Export CPU topology info via sysfs. Items (attributes) are similar
-to /proc/cpuinfo.
+to /proc/cpuinfo output of some architectures:
1) /sys/devices/system/cpu/cpuX/topology/physical_package_id:
4) /sys/devices/system/cpu/cpuX/topology/thread_siblings:
internal kernel map of cpuX's hardware threads within the same
- core as cpuX
+ core as cpuX.
-5) /sys/devices/system/cpu/cpuX/topology/core_siblings:
+5) /sys/devices/system/cpu/cpuX/topology/thread_siblings_list:
+
+ human-readable list of cpuX's hardware threads within the same
+ core as cpuX.
+
+6) /sys/devices/system/cpu/cpuX/topology/core_siblings:
internal kernel map of cpuX's hardware threads within the same
physical_package_id.
-6) /sys/devices/system/cpu/cpuX/topology/book_siblings:
+7) /sys/devices/system/cpu/cpuX/topology/core_siblings_list:
+
+ human-readable list of cpuX's hardware threads within the same
+ physical_package_id.
+
+8) /sys/devices/system/cpu/cpuX/topology/book_siblings:
internal kernel map of cpuX's hardware threads within the same
book_id.
+9) /sys/devices/system/cpu/cpuX/topology/book_siblings_list:
+
+ human-readable list of cpuX's hardware threads within the same
+ book_id.
+
To implement it in an architecture-neutral way, a new source file,
-drivers/base/topology.c, is to export the 4 or 6 attributes. The two book
+drivers/base/topology.c, is to export the 6 or 9 attributes. The three book
related sysfs files will only be created if CONFIG_SCHED_BOOK is selected.
For an architecture to support this feature, it must define some of
#define topology_physical_package_id(cpu)
#define topology_core_id(cpu)
#define topology_book_id(cpu)
-#define topology_thread_cpumask(cpu)
+#define topology_sibling_cpumask(cpu)
#define topology_core_cpumask(cpu)
#define topology_book_cpumask(cpu)
-The type of **_id is int.
-The type of siblings is (const) struct cpumask *.
+The type of **_id macros is int.
+The type of **_cpumask macros is (const) struct cpumask *. The latter
+correspond with appropriate **_siblings sysfs attributes (except for
+topology_sibling_cpumask() which corresponds with thread_siblings).
To be consistent on all architectures, include/linux/topology.h
provides default definitions for any of the above macros that are
not defined by include/asm-XXX/topology.h:
1) physical_package_id: -1
2) core_id: 0
-3) thread_siblings: just the given CPU
-4) core_siblings: just the given CPU
+3) sibling_cpumask: just the given CPU
+4) core_cpumask: just the given CPU
For architectures that don't support books (CONFIG_SCHED_BOOK) there are no
default definitions for topology_book_id() and topology_book_cpumask().
1. Overview
2. Scheduling algorithm
3. Scheduling Real-Time Tasks
+ 3.1 Definitions
+ 3.2 Schedulability Analysis for Uniprocessor Systems
+ 3.3 Schedulability Analysis for Multiprocessor Systems
+ 3.4 Relationship with SCHED_DEADLINE Parameters
4. Bandwidth management
4.1 System-wide settings
4.2 Task interface
"deadline", to schedule tasks. A SCHED_DEADLINE task should receive
"runtime" microseconds of execution time every "period" microseconds, and
these "runtime" microseconds are available within "deadline" microseconds
- from the beginning of the period. In order to implement this behaviour,
+ from the beginning of the period. In order to implement this behavior,
every time the task wakes up, the scheduler computes a "scheduling deadline"
consistent with the guarantee (using the CBS[2,3] algorithm). Tasks are then
scheduled using EDF[1] on these scheduling deadlines (the task with the
"admission control" strategy (see Section "4. Bandwidth management") is used
(clearly, if the system is overloaded this guarantee cannot be respected).
- Summing up, the CBS[2,3] algorithms assigns scheduling deadlines to tasks so
+ Summing up, the CBS[2,3] algorithm assigns scheduling deadlines to tasks so
that each task runs for at most its runtime every period, avoiding any
interference between different tasks (bandwidth isolation), while the EDF[1]
algorithm selects the task with the earliest scheduling deadline as the one
In more details, the CBS algorithm assigns scheduling deadlines to
tasks in the following way:
- - Each SCHED_DEADLINE task is characterised by the "runtime",
+ - Each SCHED_DEADLINE task is characterized by the "runtime",
"deadline", and "period" parameters;
- The state of the task is described by a "scheduling deadline", and
then, if the scheduling deadline is smaller than the current time, or
this condition is verified, the scheduling deadline and the
- remaining runtime are re-initialised as
+ remaining runtime are re-initialized as
scheduling deadline = current time + deadline
remaining runtime = runtime
suited for periodic or sporadic real-time tasks that need guarantees on their
timing behavior, e.g., multimedia, streaming, control applications, etc.
+3.1 Definitions
+------------------------
+
A typical real-time task is composed of a repetition of computation phases
(task instances, or jobs) which are activated on a periodic or sporadic
fashion.
- Each job J_j (where J_j is the j^th job of the task) is characterised by an
+ Each job J_j (where J_j is the j^th job of the task) is characterized by an
arrival time r_j (the time when the job starts), an amount of computation
time c_j needed to finish the job, and a job absolute deadline d_j, which
is the time within which the job should be finished. The maximum execution
- time max_j{c_j} is called "Worst Case Execution Time" (WCET) for the task.
+ time max{c_j} is called "Worst Case Execution Time" (WCET) for the task.
A real-time task can be periodic with period P if r_{j+1} = r_j + P, or
sporadic with minimum inter-arrival time P is r_{j+1} >= r_j + P. Finally,
d_j = r_j + D, where D is the task's relative deadline.
- The utilisation of a real-time task is defined as the ratio between its
+ Summing up, a real-time task can be described as
+ Task = (WCET, D, P)
+
+ The utilization of a real-time task is defined as the ratio between its
WCET and its period (or minimum inter-arrival time), and represents
the fraction of CPU time needed to execute the task.
- If the total utilisation sum_i(WCET_i/P_i) is larger than M (with M equal
+ If the total utilization U=sum(WCET_i/P_i) is larger than M (with M equal
to the number of CPUs), then the scheduler is unable to respect all the
deadlines.
- Note that total utilisation is defined as the sum of the utilisations
+ Note that total utilization is defined as the sum of the utilizations
WCET_i/P_i over all the real-time tasks in the system. When considering
multiple real-time tasks, the parameters of the i-th task are indicated
with the "_i" suffix.
- Moreover, if the total utilisation is larger than M, then we risk starving
+ Moreover, if the total utilization is larger than M, then we risk starving
non- real-time tasks by real-time tasks.
- If, instead, the total utilisation is smaller than M, then non real-time
+ If, instead, the total utilization is smaller than M, then non real-time
tasks will not be starved and the system might be able to respect all the
deadlines.
As a matter of fact, in this case it is possible to provide an upper bound
More precisely, it can be proven that using a global EDF scheduler the
maximum tardiness of each task is smaller or equal than
((M − 1) · WCET_max − WCET_min)/(M − (M − 2) · U_max) + WCET_max
- where WCET_max = max_i{WCET_i} is the maximum WCET, WCET_min=min_i{WCET_i}
- is the minimum WCET, and U_max = max_i{WCET_i/P_i} is the maximum utilisation.
+ where WCET_max = max{WCET_i} is the maximum WCET, WCET_min=min{WCET_i}
+ is the minimum WCET, and U_max = max{WCET_i/P_i} is the maximum
+ utilization[12].
+
+3.2 Schedulability Analysis for Uniprocessor Systems
+------------------------
If M=1 (uniprocessor system), or in case of partitioned scheduling (each
real-time task is statically assigned to one and only one CPU), it is
possible to formally check if all the deadlines are respected.
If D_i = P_i for all tasks, then EDF is able to respect all the deadlines
- of all the tasks executing on a CPU if and only if the total utilisation
+ of all the tasks executing on a CPU if and only if the total utilization
of the tasks running on such a CPU is smaller or equal than 1.
If D_i != P_i for some task, then it is possible to define the density of
- a task as C_i/min{D_i,T_i}, and EDF is able to respect all the deadlines
- of all the tasks running on a CPU if the sum sum_i C_i/min{D_i,T_i} of the
- densities of the tasks running on such a CPU is smaller or equal than 1
- (notice that this condition is only sufficient, and not necessary).
+ a task as WCET_i/min{D_i,P_i}, and EDF is able to respect all the deadlines
+ of all the tasks running on a CPU if the sum of the densities of the tasks
+ running on such a CPU is smaller or equal than 1:
+ sum(WCET_i / min{D_i, P_i}) <= 1
+ It is important to notice that this condition is only sufficient, and not
+ necessary: there are task sets that are schedulable, but do not respect the
+ condition. For example, consider the task set {Task_1,Task_2} composed by
+ Task_1=(50ms,50ms,100ms) and Task_2=(10ms,100ms,100ms).
+ EDF is clearly able to schedule the two tasks without missing any deadline
+ (Task_1 is scheduled as soon as it is released, and finishes just in time
+ to respect its deadline; Task_2 is scheduled immediately after Task_1, hence
+ its response time cannot be larger than 50ms + 10ms = 60ms) even if
+ 50 / min{50,100} + 10 / min{100, 100} = 50 / 50 + 10 / 100 = 1.1
+ Of course it is possible to test the exact schedulability of tasks with
+ D_i != P_i (checking a condition that is both sufficient and necessary),
+ but this cannot be done by comparing the total utilization or density with
+ a constant. Instead, the so called "processor demand" approach can be used,
+ computing the total amount of CPU time h(t) needed by all the tasks to
+ respect all of their deadlines in a time interval of size t, and comparing
+ such a time with the interval size t. If h(t) is smaller than t (that is,
+ the amount of time needed by the tasks in a time interval of size t is
+ smaller than the size of the interval) for all the possible values of t, then
+ EDF is able to schedule the tasks respecting all of their deadlines. Since
+ performing this check for all possible values of t is impossible, it has been
+ proven[4,5,6] that it is sufficient to perform the test for values of t
+ between 0 and a maximum value L. The cited papers contain all of the
+ mathematical details and explain how to compute h(t) and L.
+ In any case, this kind of analysis is too complex as well as too
+ time-consuming to be performed on-line. Hence, as explained in Section
+ 4 Linux uses an admission test based on the tasks' utilizations.
+
+3.3 Schedulability Analysis for Multiprocessor Systems
+------------------------
On multiprocessor systems with global EDF scheduling (non partitioned
systems), a sufficient test for schedulability can not be based on the
- utilisations (it can be shown that task sets with utilisations slightly
- larger than 1 can miss deadlines regardless of the number of CPUs M).
- However, as previously stated, enforcing that the total utilisation is smaller
- than M is enough to guarantee that non real-time tasks are not starved and
- that the tardiness of real-time tasks has an upper bound.
+ utilizations or densities: it can be shown that even if D_i = P_i task
+ sets with utilizations slightly larger than 1 can miss deadlines regardless
+ of the number of CPUs.
+
+ Consider a set {Task_1,...Task_{M+1}} of M+1 tasks on a system with M
+ CPUs, with the first task Task_1=(P,P,P) having period, relative deadline
+ and WCET equal to P. The remaining M tasks Task_i=(e,P-1,P-1) have an
+ arbitrarily small worst case execution time (indicated as "e" here) and a
+ period smaller than the one of the first task. Hence, if all the tasks
+ activate at the same time t, global EDF schedules these M tasks first
+ (because their absolute deadlines are equal to t + P - 1, hence they are
+ smaller than the absolute deadline of Task_1, which is t + P). As a
+ result, Task_1 can be scheduled only at time t + e, and will finish at
+ time t + e + P, after its absolute deadline. The total utilization of the
+ task set is U = M · e / (P - 1) + P / P = M · e / (P - 1) + 1, and for small
+ values of e this can become very close to 1. This is known as "Dhall's
+ effect"[7]. Note: the example in the original paper by Dhall has been
+ slightly simplified here (for example, Dhall more correctly computed
+ lim_{e->0}U).
+
+ More complex schedulability tests for global EDF have been developed in
+ real-time literature[8,9], but they are not based on a simple comparison
+ between total utilization (or density) and a fixed constant. If all tasks
+ have D_i = P_i, a sufficient schedulability condition can be expressed in
+ a simple way:
+ sum(WCET_i / P_i) <= M - (M - 1) · U_max
+ where U_max = max{WCET_i / P_i}[10]. Notice that for U_max = 1,
+ M - (M - 1) · U_max becomes M - M + 1 = 1 and this schedulability condition
+ just confirms the Dhall's effect. A more complete survey of the literature
+ about schedulability tests for multi-processor real-time scheduling can be
+ found in [11].
+
+ As seen, enforcing that the total utilization is smaller than M does not
+ guarantee that global EDF schedules the tasks without missing any deadline
+ (in other words, global EDF is not an optimal scheduling algorithm). However,
+ a total utilization smaller than M is enough to guarantee that non real-time
+ tasks are not starved and that the tardiness of real-time tasks has an upper
+ bound[12] (as previously noted). Different bounds on the maximum tardiness
+ experienced by real-time tasks have been developed in various papers[13,14],
+ but the theoretical result that is important for SCHED_DEADLINE is that if
+ the total utilization is smaller or equal than M then the response times of
+ the tasks are limited.
+
+3.4 Relationship with SCHED_DEADLINE Parameters
+------------------------
- SCHED_DEADLINE can be used to schedule real-time tasks guaranteeing that
- the jobs' deadlines of a task are respected. In order to do this, a task
- must be scheduled by setting:
+ Finally, it is important to understand the relationship between the
+ SCHED_DEADLINE scheduling parameters described in Section 2 (runtime,
+ deadline and period) and the real-time task parameters (WCET, D, P)
+ described in this section. Note that the tasks' temporal constraints are
+ represented by its absolute deadlines d_j = r_j + D described above, while
+ SCHED_DEADLINE schedules the tasks according to scheduling deadlines (see
+ Section 2).
+ If an admission test is used to guarantee that the scheduling deadlines
+ are respected, then SCHED_DEADLINE can be used to schedule real-time tasks
+ guaranteeing that all the jobs' deadlines of a task are respected.
+ In order to do this, a task must be scheduled by setting:
- runtime >= WCET
- deadline = D
- period <= P
- IOW, if runtime >= WCET and if period is >= P, then the scheduling deadlines
+ IOW, if runtime >= WCET and if period is <= P, then the scheduling deadlines
and the absolute deadlines (d_j) coincide, so a proper admission control
allows to respect the jobs' absolute deadlines for this task (this is what is
called "hard schedulability property" and is an extension of Lemma 1 of [2]).
Symposium, 1998. http://retis.sssup.it/~giorgio/paps/1998/rtss98-cbs.pdf
3 - L. Abeni. Server Mechanisms for Multimedia Applications. ReTiS Lab
Technical Report. http://disi.unitn.it/~abeni/tr-98-01.pdf
+ 4 - J. Y. Leung and M.L. Merril. A Note on Preemptive Scheduling of
+ Periodic, Real-Time Tasks. Information Processing Letters, vol. 11,
+ no. 3, pp. 115-118, 1980.
+ 5 - S. K. Baruah, A. K. Mok and L. E. Rosier. Preemptively Scheduling
+ Hard-Real-Time Sporadic Tasks on One Processor. Proceedings of the
+ 11th IEEE Real-time Systems Symposium, 1990.
+ 6 - S. K. Baruah, L. E. Rosier and R. R. Howell. Algorithms and Complexity
+ Concerning the Preemptive Scheduling of Periodic Real-Time tasks on
+ One Processor. Real-Time Systems Journal, vol. 4, no. 2, pp 301-324,
+ 1990.
+ 7 - S. J. Dhall and C. L. Liu. On a real-time scheduling problem. Operations
+ research, vol. 26, no. 1, pp 127-140, 1978.
+ 8 - T. Baker. Multiprocessor EDF and Deadline Monotonic Schedulability
+ Analysis. Proceedings of the 24th IEEE Real-Time Systems Symposium, 2003.
+ 9 - T. Baker. An Analysis of EDF Schedulability on a Multiprocessor.
+ IEEE Transactions on Parallel and Distributed Systems, vol. 16, no. 8,
+ pp 760-768, 2005.
+ 10 - J. Goossens, S. Funk and S. Baruah, Priority-Driven Scheduling of
+ Periodic Task Systems on Multiprocessors. Real-Time Systems Journal,
+ vol. 25, no. 2–3, pp. 187–205, 2003.
+ 11 - R. Davis and A. Burns. A Survey of Hard Real-Time Scheduling for
+ Multiprocessor Systems. ACM Computing Surveys, vol. 43, no. 4, 2011.
+ http://www-users.cs.york.ac.uk/~robdavis/papers/MPSurveyv5.0.pdf
+ 12 - U. C. Devi and J. H. Anderson. Tardiness Bounds under Global EDF
+ Scheduling on a Multiprocessor. Real-Time Systems Journal, vol. 32,
+ no. 2, pp 133-189, 2008.
+ 13 - P. Valente and G. Lipari. An Upper Bound to the Lateness of Soft
+ Real-Time Tasks Scheduled by EDF on Multiprocessors. Proceedings of
+ the 26th IEEE Real-Time Systems Symposium, 2005.
+ 14 - J. Erickson, U. Devi and S. Baruah. Improved tardiness bounds for
+ Global EDF. Proceedings of the 22nd Euromicro Conference on
+ Real-Time Systems, 2010.
+
4. Bandwidth management
=======================
no guarantee can be given on the actual scheduling of the -deadline tasks.
As already stated in Section 3, a necessary condition to be respected to
- correctly schedule a set of real-time tasks is that the total utilisation
+ correctly schedule a set of real-time tasks is that the total utilization
is smaller than M. When talking about -deadline tasks, this requires that
the sum of the ratio between runtime and period for all tasks is smaller
- than M. Notice that the ratio runtime/period is equivalent to the utilisation
+ than M. Notice that the ratio runtime/period is equivalent to the utilization
of a "traditional" real-time task, and is also often referred to as
"bandwidth".
The interface used to control the CPU bandwidth that can be allocated
The system wide settings are configured under the /proc virtual file system.
For now the -rt knobs are used for -deadline admission control and the
- -deadline runtime is accounted against the -rt runtime. We realise that this
+ -deadline runtime is accounted against the -rt runtime. We realize that this
isn't entirely desirable; however, it is better to have a small interface for
now, and be able to change it easily later. The ideal situation (see 5.) is to
run -rt tasks from a -deadline server; in which case the -rt bandwidth is a
#include <linux/smp.h>
#include <linux/interrupt.h>
#include <linux/module.h>
-
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
extern void die_if_kernel(char *,struct pt_regs *,long, unsigned long *);
/* If we're in an interrupt context, or have no user context,
we must not take the fault. */
- if (!mm || in_atomic())
+ if (!mm || faulthandler_disabled())
goto no_context;
#ifdef CONFIG_ALPHA_LARGE_VMALLOC
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
return -EFAULT;
- pagefault_disable(); /* implies preempt_disable() */
+ pagefault_disable();
switch (op) {
case FUTEX_OP_SET:
ret = -ENOSYS;
}
- pagefault_enable(); /* subsumes preempt_enable() */
+ pagefault_enable();
if (!ret) {
switch (cmp) {
return ret;
}
-/* Compare-xchg with preemption disabled.
+/* Compare-xchg with pagefaults disabled.
* Notes:
* -Best-Effort: Exchg happens only if compare succeeds.
* If compare fails, returns; leaving retry/looping to upper layers
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
return -EFAULT;
- pagefault_disable(); /* implies preempt_disable() */
+ pagefault_disable();
/* TBD : can use llock/scond */
__asm__ __volatile__(
: "r"(oldval), "r"(newval), "r"(uaddr), "ir"(-EFAULT)
: "cc", "memory");
- pagefault_enable(); /* subsumes preempt_enable() */
+ pagefault_enable();
*uval = val;
return val;
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (faulthandler_disabled() || !mm)
goto no_context;
if (user_mode(regs))
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
return -EFAULT;
+ preempt_disable();
__asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n"
"1: " TUSER(ldr) " %1, [%4]\n"
" teq %1, %2\n"
: "cc", "memory");
*uval = val;
+ preempt_enable();
+
return ret;
}
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
return -EFAULT;
- pagefault_disable(); /* implies preempt_disable() */
+#ifndef CONFIG_SMP
+ preempt_disable();
+#endif
+ pagefault_disable();
switch (op) {
case FUTEX_OP_SET:
ret = -ENOSYS;
}
- pagefault_enable(); /* subsumes preempt_enable() */
+ pagefault_enable();
+#ifndef CONFIG_SMP
+ preempt_enable();
+#endif
if (!ret) {
switch (cmp) {
#define topology_physical_package_id(cpu) (cpu_topology[cpu].socket_id)
#define topology_core_id(cpu) (cpu_topology[cpu].core_id)
#define topology_core_cpumask(cpu) (&cpu_topology[cpu].core_sibling)
-#define topology_thread_cpumask(cpu) (&cpu_topology[cpu].thread_sibling)
+#define topology_sibling_cpumask(cpu) (&cpu_topology[cpu].thread_sibling)
void init_cpu_topology(void);
void store_cpu_topology(unsigned int cpuid);
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (faulthandler_disabled() || !mm)
goto no_context;
if (user_mode(regs))
void *kmap;
int type;
+ preempt_disable();
pagefault_disable();
if (!PageHighMem(page))
return page_address(page);
kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)]));
}
pagefault_enable();
+ preempt_enable();
}
EXPORT_SYMBOL(__kunmap_atomic);
int idx, type;
struct page *page = pfn_to_page(pfn);
+ preempt_disable();
pagefault_disable();
if (!PageHighMem(page))
return page_address(page);
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
return -EFAULT;
- pagefault_disable(); /* implies preempt_disable() */
+ pagefault_disable();
switch (op) {
case FUTEX_OP_SET:
ret = -ENOSYS;
}
- pagefault_enable(); /* subsumes preempt_enable() */
+ pagefault_enable();
if (!ret) {
switch (cmp) {
#define topology_physical_package_id(cpu) (cpu_topology[cpu].cluster_id)
#define topology_core_id(cpu) (cpu_topology[cpu].core_id)
#define topology_core_cpumask(cpu) (&cpu_topology[cpu].core_sibling)
-#define topology_thread_cpumask(cpu) (&cpu_topology[cpu].thread_sibling)
+#define topology_sibling_cpumask(cpu) (&cpu_topology[cpu].thread_sibling)
void init_cpu_topology(void);
void store_cpu_topology(unsigned int cpuid);
* If we're in an interrupt or have no user context, we must not take
* the fault.
*/
- if (in_atomic() || !mm)
+ if (faulthandler_disabled() || !mm)
goto no_context;
if (user_mode(regs))
* @x: Value to copy to user space.
* @ptr: Destination address, in user space.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* This macro copies a single simple value from kernel space to user
* space. It supports simple types like char and int, but not larger
* @x: Variable to store result.
* @ptr: Source address, in user space.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* This macro copies a single simple variable from user space to kernel
* space. It supports simple types like char and int, but not larger
* @x: Value to copy to user space.
* @ptr: Destination address, in user space.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* This macro copies a single simple value from kernel space to user
* space. It supports simple types like char and int, but not larger
* @x: Variable to store result.
* @ptr: Source address, in user space.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* This macro copies a single simple variable from user space to kernel
* space. It supports simple types like char and int, but not larger
#include <linux/pagemap.h>
#include <linux/kdebug.h>
#include <linux/kprobes.h>
+#include <linux/uaccess.h>
#include <asm/mmu_context.h>
#include <asm/sysreg.h>
#include <asm/tlb.h>
-#include <asm/uaccess.h>
#ifdef CONFIG_KPROBES
static inline int notify_page_fault(struct pt_regs *regs, int trap)
* If we're in an interrupt or have no user context, we must
* not take the fault...
*/
- if (in_atomic() || !mm || regs->sr & SYSREG_BIT(GM))
+ if (faulthandler_disabled() || !mm || regs->sr & SYSREG_BIT(GM))
goto no_context;
local_irq_enable();
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/wait.h>
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
#include <arch/system.h>
extern int find_fixup_code(struct pt_regs *);
info.si_code = SEGV_MAPERR;
/*
- * If we're in an interrupt or "atomic" operation or have no
+ * If we're in an interrupt, have pagefaults disabled or have no
* user context, we must not take the fault.
*/
- if (in_atomic() || !mm)
+ if (faulthandler_disabled() || !mm)
goto no_context;
if (user_mode(regs))
#include <linux/kernel.h>
#include <linux/ptrace.h>
#include <linux/hardirq.h>
+#include <linux/uaccess.h>
#include <asm/pgtable.h>
-#include <asm/uaccess.h>
#include <asm/gdb-stub.h>
/*****************************************************************************/
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (faulthandler_disabled() || !mm)
goto no_context;
if (user_mode(__frame))
unsigned long paddr;
int type;
+ preempt_disable();
pagefault_disable();
type = kmap_atomic_idx_push();
paddr = page_to_phys(page);
}
kmap_atomic_idx_pop();
pagefault_enable();
+ preempt_enable();
}
EXPORT_SYMBOL(__kunmap_atomic);
* @addr: User space pointer to start of block to check
* @size: Size of block to check
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Checks if a pointer to a block of memory in user space is valid.
*
#define topology_physical_package_id(cpu) (cpu_data(cpu)->socket_id)
#define topology_core_id(cpu) (cpu_data(cpu)->core_id)
#define topology_core_cpumask(cpu) (&cpu_core_map[cpu])
-#define topology_thread_cpumask(cpu) (&per_cpu(cpu_sibling_map, cpu))
+#define topology_sibling_cpumask(cpu) (&per_cpu(cpu_sibling_map, cpu))
#endif
extern void arch_fix_phys_package_id(int num, u32 slot);
#include <linux/kprobes.h>
#include <linux/kdebug.h>
#include <linux/prefetch.h>
+#include <linux/uaccess.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
-#include <asm/uaccess.h>
extern int die(char *, struct pt_regs *, long);
/*
* If we're in an interrupt or have no user context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (faulthandler_disabled() || !mm)
goto no_context;
#ifdef CONFIG_VIRTUAL_MEM_MAP
* @addr: User space pointer to start of block to check
* @size: Size of block to check
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Checks if a pointer to a block of memory in user space is valid.
*
* @x: Variable to store result.
* @ptr: Source address, in user space.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* This macro copies a single simple variable from user space to kernel
* space. It supports simple types like char and int, but not larger
* @x: Value to copy to user space.
* @ptr: Destination address, in user space.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* This macro copies a single simple value from kernel space to user
* space. It supports simple types like char and int, but not larger
* @x: Variable to store result.
* @ptr: Source address, in user space.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* This macro copies a single simple variable from user space to kernel
* space. It supports simple types like char and int, but not larger
* @x: Value to copy to user space.
* @ptr: Destination address, in user space.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* This macro copies a single simple value from kernel space to user
* space. It supports simple types like char and int, but not larger
* @from: Source address, in kernel space.
* @n: Number of bytes to copy.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Copy data from kernel space to user space. Caller must check
* the specified block with access_ok() before calling this function.
* @from: Source address, in kernel space.
* @n: Number of bytes to copy.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Copy data from kernel space to user space.
*
* @from: Source address, in user space.
* @n: Number of bytes to copy.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Copy data from user space to kernel space. Caller must check
* the specified block with access_ok() before calling this function.
* @from: Source address, in user space.
* @n: Number of bytes to copy.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Copy data from user space to kernel space.
*
* strlen_user: - Get the size of a string in user space.
* @str: The string to measure.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Get the size of a NUL-terminated string in user space.
*
#include <linux/vt_kern.h> /* For unblank_screen() */
#include <linux/highmem.h>
#include <linux/module.h>
+#include <linux/uaccess.h>
#include <asm/m32r.h>
-#include <asm/uaccess.h>
#include <asm/hardirq.h>
#include <asm/mmu_context.h>
#include <asm/tlbflush.h>
mm = tsk->mm;
/*
- * If we're in an interrupt or have no user context or are running in an
- * atomic region then we must not take the fault..
+ * If we're in an interrupt or have no user context or have pagefaults
+ * disabled then we must not take the fault.
*/
- if (in_atomic() || !mm)
+ if (faulthandler_disabled() || !mm)
goto bad_area_nosemaphore;
if (error_code & ACE_USERMODE)
#define _M68K_IRQFLAGS_H
#include <linux/types.h>
-#ifdef CONFIG_MMU
-#include <linux/preempt_mask.h>
-#endif
#include <linux/preempt.h>
#include <asm/thread_info.h>
#include <asm/entry.h>
#include <linux/ptrace.h>
#include <linux/interrupt.h>
#include <linux/module.h>
+#include <linux/uaccess.h>
#include <asm/setup.h>
#include <asm/traps.h>
-#include <asm/uaccess.h>
#include <asm/pgalloc.h>
extern void die_if_kernel(char *, struct pt_regs *, long);
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (faulthandler_disabled() || !mm)
goto no_context;
if (user_mode(regs))
mm = tsk->mm;
- if (in_atomic() || !mm)
+ if (faulthandler_disabled() || !mm)
goto no_context;
if (user_mode(regs))
unsigned long vaddr;
int type;
- /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
+ preempt_disable();
pagefault_disable();
if (!PageHighMem(page))
return page_address(page);
}
pagefault_enable();
+ preempt_enable();
}
EXPORT_SYMBOL(__kunmap_atomic);
unsigned long vaddr;
int type;
+ preempt_disable();
pagefault_disable();
type = kmap_atomic_idx_push();
* @x: Variable to store result.
* @ptr: Source address, in user space.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* This macro copies a single simple variable from user space to kernel
* space. It supports simple types like char and int, but not larger
* @x: Value to copy to user space.
* @ptr: Destination address, in user space.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* This macro copies a single simple value from kernel space to user
* space. It supports simple types like char and int, but not larger
if ((error_code & 0x13) == 0x13 || (error_code & 0x11) == 0x11)
is_write = 0;
- if (unlikely(in_atomic() || !mm)) {
+ if (unlikely(faulthandler_disabled() || !mm)) {
if (kernel_mode(regs))
goto bad_area_nosemaphore;
- /* in_atomic() in user mode is really bad,
+ /* faulthandler_disabled() in user mode is really bad,
as is current->mm == NULL. */
- pr_emerg("Page fault in user mode with in_atomic(), mm = %p\n",
- mm);
+ pr_emerg("Page fault in user mode with faulthandler_disabled(), mm = %p\n",
+ mm);
pr_emerg("r15 = %lx MSR = %lx\n",
regs->r15, regs->msr);
die("Weird page fault", regs, SIGSEGV);
unsigned long vaddr;
int idx, type;
- /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
+ preempt_disable();
pagefault_disable();
if (!PageHighMem(page))
return page_address(page);
if (vaddr < __fix_to_virt(FIX_KMAP_END)) {
pagefault_enable();
+ preempt_enable();
return;
}
#endif
kmap_atomic_idx_pop();
pagefault_enable();
+ preempt_enable();
}
EXPORT_SYMBOL(__kunmap_atomic);
#define topology_physical_package_id(cpu) (cpu_data[cpu].package)
#define topology_core_id(cpu) (cpu_data[cpu].core)
#define topology_core_cpumask(cpu) (&cpu_core_map[cpu])
-#define topology_thread_cpumask(cpu) (&cpu_sibling_map[cpu])
+#define topology_sibling_cpumask(cpu) (&cpu_sibling_map[cpu])
#endif
#endif /* __ASM_TOPOLOGY_H */
* @addr: User space pointer to start of block to check
* @size: Size of block to check
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Checks if a pointer to a block of memory in user space is valid.
*
* @x: Value to copy to user space.
* @ptr: Destination address, in user space.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* This macro copies a single simple value from kernel space to user
* space. It supports simple types like char and int, but not larger
* @x: Variable to store result.
* @ptr: Source address, in user space.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* This macro copies a single simple variable from user space to kernel
* space. It supports simple types like char and int, but not larger
* @x: Value to copy to user space.
* @ptr: Destination address, in user space.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* This macro copies a single simple value from kernel space to user
* space. It supports simple types like char and int, but not larger
* @x: Variable to store result.
* @ptr: Source address, in user space.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* This macro copies a single simple variable from user space to kernel
* space. It supports simple types like char and int, but not larger
* @x: Value to copy to user space.
* @ptr: Destination address, in user space.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* This macro copies a single simple value from kernel space to user
* space. It supports simple types like char and int, but not larger
* @x: Variable to store result.
* @ptr: Source address, in user space.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* This macro copies a single simple variable from user space to kernel
* space. It supports simple types like char and int, but not larger
* @x: Value to copy to user space.
* @ptr: Destination address, in user space.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* This macro copies a single simple value from kernel space to user
* space. It supports simple types like char and int, but not larger
* @x: Variable to store result.
* @ptr: Source address, in user space.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* This macro copies a single simple variable from user space to kernel
* space. It supports simple types like char and int, but not larger
* @from: Source address, in kernel space.
* @n: Number of bytes to copy.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Copy data from kernel space to user space. Caller must check
* the specified block with access_ok() before calling this function.
* @from: Source address, in kernel space.
* @n: Number of bytes to copy.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Copy data from kernel space to user space.
*
* @from: Source address, in user space.
* @n: Number of bytes to copy.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Copy data from user space to kernel space. Caller must check
* the specified block with access_ok() before calling this function.
* @from: Source address, in user space.
* @n: Number of bytes to copy.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Copy data from user space to kernel space.
*
* strlen_user: - Get the size of a string in user space.
* @str: The string to measure.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Get the size of a NUL-terminated string in user space.
*
* strnlen_user: - Get the size of a string in user space.
* @str: The string to measure.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Get the size of a NUL-terminated string in user space.
*
extern int fpcsr_pending(unsigned int __user *fpcsr);
/* Make sure we will not lose FPU ownership */
-#ifdef CONFIG_PREEMPT
-#define lock_fpu_owner() preempt_disable()
-#define unlock_fpu_owner() preempt_enable()
-#else
-#define lock_fpu_owner() pagefault_disable()
-#define unlock_fpu_owner() pagefault_enable()
-#endif
+#define lock_fpu_owner() ({ preempt_disable(); pagefault_disable(); })
+#define unlock_fpu_owner() ({ pagefault_enable(); preempt_enable(); })
#endif /* __SIGNAL_COMMON_H */
#include <linux/module.h>
#include <linux/kprobes.h>
#include <linux/perf_event.h>
+#include <linux/uaccess.h>
#include <asm/branch.h>
#include <asm/mmu_context.h>
-#include <asm/uaccess.h>
#include <asm/ptrace.h>
#include <asm/highmem.h> /* For VMALLOC_END */
#include <linux/kdebug.h>
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (faulthandler_disabled() || !mm)
goto bad_area_nosemaphore;
if (user_mode(regs))
unsigned long vaddr;
int idx, type;
- /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
+ preempt_disable();
pagefault_disable();
if (!PageHighMem(page))
return page_address(page);
if (vaddr < FIXADDR_START) { // FIXME
pagefault_enable();
+ preempt_enable();
return;
}
#endif
kmap_atomic_idx_pop();
pagefault_enable();
+ preempt_enable();
}
EXPORT_SYMBOL(__kunmap_atomic);
unsigned long vaddr;
int idx, type;
+ preempt_disable();
pagefault_disable();
type = kmap_atomic_idx_push();
BUG_ON(Page_dcache_dirty(page));
+ preempt_disable();
pagefault_disable();
idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1);
idx += in_interrupt() ? FIX_N_COLOURS : 0;
write_c0_entryhi(old_ctx);
local_irq_restore(flags);
pagefault_enable();
+ preempt_enable();
}
void copy_user_highpage(struct page *to, struct page *from,
unsigned long vaddr;
int idx, type;
+ preempt_disable();
pagefault_disable();
if (page < highmem_start_page)
return page_address(page);
if (vaddr < FIXADDR_START) { /* FIXME */
pagefault_enable();
+ preempt_enable();
return;
}
kmap_atomic_idx_pop();
pagefault_enable();
+ preempt_enable();
}
#endif /* __KERNEL__ */
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/vt_kern.h> /* For unblank_screen() */
+#include <linux/uaccess.h>
-#include <asm/uaccess.h>
#include <asm/pgalloc.h>
#include <asm/hardirq.h>
#include <asm/cpu-regs.h>
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (faulthandler_disabled() || !mm)
goto no_context;
if ((fault_code & MMUFCR_xFC_ACCESS) == MMUFCR_xFC_ACCESS_USR)
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (faulthandler_disabled() || !mm)
goto bad_area_nosemaphore;
if (user_mode(regs))
static inline void *kmap_atomic(struct page *page)
{
+ preempt_disable();
pagefault_disable();
return page_address(page);
}
{
flush_kernel_dcache_page_addr(addr);
pagefault_enable();
+ preempt_enable();
}
#define kmap_atomic_prot(page, prot) kmap_atomic(page)
#include <linux/console.h>
#include <linux/bug.h>
#include <linux/ratelimit.h>
+#include <linux/uaccess.h>
#include <asm/assembly.h>
-#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/traps.h>
* unless pagefault_disable() was called before.
*/
- if (fault_space == 0 && !in_atomic())
+ if (fault_space == 0 && !faulthandler_disabled())
{
pdc_chassis_send_status(PDC_CHASSIS_DIRECT_PANIC);
parisc_terminate("Kernel Fault", regs, code, fault_address);
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/module.h>
+#include <linux/uaccess.h>
-#include <asm/uaccess.h>
#include <asm/traps.h>
/* Various important other fields */
int fault;
unsigned int flags;
- if (in_atomic())
+ if (pagefault_disabled())
goto no_context;
tsk = current;
#include <asm/smp.h>
#define topology_physical_package_id(cpu) (cpu_to_chip_id(cpu))
-#define topology_thread_cpumask(cpu) (per_cpu(cpu_sibling_map, cpu))
+#define topology_sibling_cpumask(cpu) (per_cpu(cpu_sibling_map, cpu))
#define topology_core_cpumask(cpu) (per_cpu(cpu_core_map, cpu))
#define topology_core_id(cpu) (cpu_to_core_id(cpu))
#endif
if (in_interrupt())
return 0;
- /* This acts as preempt_disable() as well and will make
- * enable_kernel_altivec(). We need to disable page faults
- * as they can call schedule and thus make us lose the VMX
- * context. So on page faults, we just fail which will cause
- * a fallback to the normal non-vmx copy.
+ preempt_disable();
+ /*
+ * We need to disable page faults as they can call schedule and
+ * thus make us lose the VMX context. So on page faults, we just
+ * fail which will cause a fallback to the normal non-vmx copy.
*/
pagefault_disable();
int exit_vmx_usercopy(void)
{
pagefault_enable();
+ preempt_enable();
return 0;
}
#include <linux/ratelimit.h>
#include <linux/context_tracking.h>
#include <linux/hugetlb.h>
+#include <linux/uaccess.h>
#include <asm/firmware.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/mmu.h>
#include <asm/mmu_context.h>
-#include <asm/uaccess.h>
#include <asm/tlbflush.h>
#include <asm/siginfo.h>
#include <asm/debug.h>
if (!arch_irq_disabled_regs(regs))
local_irq_enable();
- if (in_atomic() || mm == NULL) {
+ if (faulthandler_disabled() || mm == NULL) {
if (!user_mode(regs)) {
rc = SIGSEGV;
goto bail;
}
- /* in_atomic() in user mode is really bad,
+ /* faulthandler_disabled() in user mode is really bad,
as is current->mm == NULL. */
printk(KERN_EMERG "Page fault in user mode with "
- "in_atomic() = %d mm = %p\n", in_atomic(), mm);
+ "faulthandler_disabled() = %d mm = %p\n",
+ faulthandler_disabled(), mm);
printk(KERN_EMERG "NIP = %lx MSR = %lx\n",
regs->nip, regs->msr);
die("Weird page fault", regs, SIGSEGV);
unsigned long vaddr;
int idx, type;
- /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
+ preempt_disable();
pagefault_disable();
if (!PageHighMem(page))
return page_address(page);
if (vaddr < __fix_to_virt(FIX_KMAP_END)) {
pagefault_enable();
+ preempt_enable();
return;
}
kmap_atomic_idx_pop();
pagefault_enable();
+ preempt_enable();
}
EXPORT_SYMBOL(__kunmap_atomic);
static int mm_is_core_local(struct mm_struct *mm)
{
return cpumask_subset(mm_cpumask(mm),
- topology_thread_cpumask(smp_processor_id()));
+ topology_sibling_cpumask(smp_processor_id()));
}
struct tlb_flush_param {
#define topology_physical_package_id(cpu) (per_cpu(cpu_topology, cpu).socket_id)
#define topology_thread_id(cpu) (per_cpu(cpu_topology, cpu).thread_id)
-#define topology_thread_cpumask(cpu) (&per_cpu(cpu_topology, cpu).thread_mask)
+#define topology_sibling_cpumask(cpu) \
+ (&per_cpu(cpu_topology, cpu).thread_mask)
#define topology_core_id(cpu) (per_cpu(cpu_topology, cpu).core_id)
#define topology_core_cpumask(cpu) (&per_cpu(cpu_topology, cpu).core_mask)
#define topology_book_id(cpu) (per_cpu(cpu_topology, cpu).book_id)
* @from: Source address, in user space.
* @n: Number of bytes to copy.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Copy data from user space to kernel space. Caller must check
* the specified block with access_ok() before calling this function.
* @from: Source address, in kernel space.
* @n: Number of bytes to copy.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Copy data from kernel space to user space. Caller must check
* the specified block with access_ok() before calling this function.
* @from: Source address, in kernel space.
* @n: Number of bytes to copy.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Copy data from kernel space to user space.
*
* @from: Source address, in user space.
* @n: Number of bytes to copy.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Copy data from user space to kernel space.
*
* strlen_user: - Get the size of a string in user space.
* @str: The string to measure.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Get the size of a NUL-terminated string in user space.
*
* user context.
*/
fault = VM_FAULT_BADCONTEXT;
- if (unlikely(!user_space_fault(regs) || in_atomic() || !mm))
+ if (unlikely(!user_space_fault(regs) || faulthandler_disabled() || !mm))
goto out;
address = trans_exc_code & __FAIL_ADDR_MASK;
* @addr: User space pointer to start of block to check
* @size: Size of block to check
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Checks if a pointer to a block of memory in user space is valid.
*
* @x: Value to copy to user space.
* @ptr: Destination address, in user space.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* This macro copies a single simple value from kernel space to user
* space. It supports simple types like char and int, but not larger
* @x: Variable to store result.
* @ptr: Source address, in user space.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* This macro copies a single simple variable from user space to kernel
* space. It supports simple types like char and int, but not larger
* @x: Value to copy to user space.
* @ptr: Destination address, in user space.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* This macro copies a single simple value from kernel space to user
* space. It supports simple types like char and int, but not larger
* @x: Variable to store result.
* @ptr: Source address, in user space.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* This macro copies a single simple variable from user space to kernel
* space. It supports simple types like char and int, but not larger
#include <linux/string.h>
#include <linux/types.h>
#include <linux/ptrace.h>
+#include <linux/uaccess.h>
/*
* This routine handles page faults. It determines the address,
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (pagefault_disabled() || !mm)
goto bad_area_nosemaphore;
if (user_mode(regs))
#include <linux/kprobes.h>
#include <linux/perf_event.h>
#include <linux/kdebug.h>
+#include <linux/uaccess.h>
#include <asm/io_trapped.h>
#include <asm/mmu_context.h>
#include <asm/tlbflush.h>
/*
* If we're in an interrupt, have no user context or are running
- * in an atomic region then we must not take the fault:
+ * with pagefaults disabled then we must not take the fault:
*/
- if (unlikely(in_atomic() || !mm)) {
+ if (unlikely(faulthandler_disabled() || !mm)) {
bad_area_nosemaphore(regs, error_code, address);
return;
}
#define topology_physical_package_id(cpu) (cpu_data(cpu).proc_id)
#define topology_core_id(cpu) (cpu_data(cpu).core_id)
#define topology_core_cpumask(cpu) (&cpu_core_sib_map[cpu])
-#define topology_thread_cpumask(cpu) (&per_cpu(cpu_sibling_map, cpu))
+#define topology_sibling_cpumask(cpu) (&per_cpu(cpu_sibling_map, cpu))
#endif /* CONFIG_SMP */
extern cpumask_t cpu_core_map[NR_CPUS];
#include <linux/perf_event.h>
#include <linux/interrupt.h>
#include <linux/kdebug.h>
+#include <linux/uaccess.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/setup.h>
#include <asm/smp.h>
#include <asm/traps.h>
-#include <asm/uaccess.h>
#include "mm_32.h"
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (pagefault_disabled() || !mm)
goto no_context;
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
#include <linux/kdebug.h>
#include <linux/percpu.h>
#include <linux/context_tracking.h>
+#include <linux/uaccess.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/openprom.h>
#include <asm/oplib.h>
-#include <asm/uaccess.h>
#include <asm/asi.h>
#include <asm/lsu.h>
#include <asm/sections.h>
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (faulthandler_disabled() || !mm)
goto intr_or_no_mm;
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
unsigned long vaddr;
long idx, type;
- /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
+ preempt_disable();
pagefault_disable();
if (!PageHighMem(page))
return page_address(page);
if (vaddr < FIXADDR_START) { // FIXME
pagefault_enable();
+ preempt_enable();
return;
}
kmap_atomic_idx_pop();
pagefault_enable();
+ preempt_enable();
}
EXPORT_SYMBOL(__kunmap_atomic);
struct mm_struct *mm = current->mm;
struct tsb_config *tp;
- if (in_atomic() || !mm) {
+ if (faulthandler_disabled() || !mm) {
const struct exception_table_entry *entry;
entry = search_exception_tables(regs->tpc);
#define topology_physical_package_id(cpu) ((void)(cpu), 0)
#define topology_core_id(cpu) (cpu)
#define topology_core_cpumask(cpu) ((void)(cpu), cpu_online_mask)
-#define topology_thread_cpumask(cpu) cpumask_of(cpu)
+#define topology_sibling_cpumask(cpu) cpumask_of(cpu)
#endif
#endif /* _ASM_TILE_TOPOLOGY_H */
* @addr: User space pointer to start of block to check
* @size: Size of block to check
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Checks if a pointer to a block of memory in user space is valid.
*
* @x: Variable to store result.
* @ptr: Source address, in user space.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* This macro copies a single simple variable from user space to kernel
* space. It supports simple types like char and int, but not larger
* @x: Value to copy to user space.
* @ptr: Destination address, in user space.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* This macro copies a single simple value from kernel space to user
* space. It supports simple types like char and int, but not larger
* @from: Source address, in kernel space.
* @n: Number of bytes to copy.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Copy data from kernel space to user space. Caller must check
* the specified block with access_ok() before calling this function.
* @from: Source address, in user space.
* @n: Number of bytes to copy.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Copy data from user space to kernel space. Caller must check
* the specified block with access_ok() before calling this function.
* @from: Source address, in user space.
* @n: Number of bytes to copy.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Copy data from user space to user space. Caller must check
* the specified blocks with access_ok() before calling this function.
/*
* If we're in an interrupt, have no user context or are running in an
- * atomic region then we must not take the fault.
+ * region with pagefaults disabled then we must not take the fault.
*/
- if (in_atomic() || !mm) {
+ if (pagefault_disabled() || !mm) {
vma = NULL; /* happy compiler */
goto bad_area_nosemaphore;
}
int idx, type;
pte_t *pte;
- /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
+ preempt_disable();
pagefault_disable();
/* Avoid icache flushes by disallowing atomic executable mappings. */
}
pagefault_enable();
+ preempt_enable();
}
EXPORT_SYMBOL(__kunmap_atomic);
#include <linux/sched.h>
#include <linux/hardirq.h>
#include <linux/module.h>
+#include <linux/uaccess.h>
#include <asm/current.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
*code_out = SEGV_MAPERR;
/*
- * If the fault was during atomic operation, don't take the fault, just
+ * If the fault was with pagefaults disabled, don't take the fault, just
* fail.
*/
- if (in_atomic())
+ if (faulthandler_disabled())
goto out_nosemaphore;
if (is_user)
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm)
+ if (faulthandler_disabled() || !mm)
goto no_context;
if (user_mode(regs))
DECLARE_PER_CPU_READ_MOSTLY(u16, cpu_llc_id);
DECLARE_PER_CPU_READ_MOSTLY(int, cpu_number);
-static inline struct cpumask *cpu_sibling_mask(int cpu)
-{
- return per_cpu(cpu_sibling_map, cpu);
-}
-
-static inline struct cpumask *cpu_core_mask(int cpu)
-{
- return per_cpu(cpu_core_map, cpu);
-}
-
static inline struct cpumask *cpu_llc_shared_mask(int cpu)
{
return per_cpu(cpu_llc_shared_map, cpu);
#ifdef ENABLE_TOPO_DEFINES
#define topology_core_cpumask(cpu) (per_cpu(cpu_core_map, cpu))
-#define topology_thread_cpumask(cpu) (per_cpu(cpu_sibling_map, cpu))
+#define topology_sibling_cpumask(cpu) (per_cpu(cpu_sibling_map, cpu))
#endif
static inline void arch_fix_phys_package_id(int num, u32 slot)
* @addr: User space pointer to start of block to check
* @size: Size of block to check
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Checks if a pointer to a block of memory in user space is valid.
*
* @x: Variable to store result.
* @ptr: Source address, in user space.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* This macro copies a single simple variable from user space to kernel
* space. It supports simple types like char and int, but not larger
* @x: Value to copy to user space.
* @ptr: Destination address, in user space.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* This macro copies a single simple value from kernel space to user
* space. It supports simple types like char and int, but not larger
* @x: Variable to store result.
* @ptr: Source address, in user space.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* This macro copies a single simple variable from user space to kernel
* space. It supports simple types like char and int, but not larger
* @x: Value to copy to user space.
* @ptr: Destination address, in user space.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* This macro copies a single simple value from kernel space to user
* space. It supports simple types like char and int, but not larger
* @from: Source address, in kernel space.
* @n: Number of bytes to copy.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Copy data from kernel space to user space. Caller must check
* the specified block with access_ok() before calling this function.
* @from: Source address, in user space.
* @n: Number of bytes to copy.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Copy data from user space to kernel space. Caller must check
* the specified block with access_ok() before calling this function.
if (!(x86_pmu.flags & PMU_FL_NO_HT_SHARING)) {
void **onln = &cpuc->kfree_on_online[X86_PERF_KFREE_SHARED];
- for_each_cpu(i, topology_thread_cpumask(cpu)) {
+ for_each_cpu(i, topology_sibling_cpumask(cpu)) {
struct intel_shared_regs *pc;
pc = per_cpu(cpu_hw_events, i).shared_regs;
if (x86_pmu.flags & PMU_FL_EXCL_CNTRS) {
int h = x86_pmu.num_counters >> 1;
- for_each_cpu(i, topology_thread_cpumask(cpu)) {
+ for_each_cpu(i, topology_sibling_cpumask(cpu)) {
struct intel_excl_cntrs *c;
c = per_cpu(cpu_hw_events, i).excl_cntrs;
if (!(x86_pmu.flags & PMU_FL_EXCL_ENABLED))
return 0;
- w = cpumask_weight(topology_thread_cpumask(cpu));
+ w = cpumask_weight(topology_sibling_cpumask(cpu));
if (w > 1) {
pr_info("PMU erratum BJ122, BV98, HSD29 worked around, HT is on\n");
return 0;
{
#ifdef CONFIG_SMP
seq_printf(m, "physical id\t: %d\n", c->phys_proc_id);
- seq_printf(m, "siblings\t: %d\n", cpumask_weight(cpu_core_mask(cpu)));
+ seq_printf(m, "siblings\t: %d\n",
+ cpumask_weight(topology_core_cpumask(cpu)));
seq_printf(m, "core id\t\t: %d\n", c->cpu_core_id);
seq_printf(m, "cpu cores\t: %d\n", c->booted_cores);
seq_printf(m, "apicid\t\t: %d\n", c->apicid);
}
/*
- * MONITOR/MWAIT with no hints, used for default default C1 state.
- * This invokes MWAIT with interrutps enabled and no flags,
- * which is backwards compatible with the original MWAIT implementation.
+ * MONITOR/MWAIT with no hints, used for default C1 state. This invokes MWAIT
+ * with interrupts enabled and no flags, which is backwards compatible with the
+ * original MWAIT implementation.
*/
-
static void mwait_idle(void)
{
if (!current_set_polling_and_test()) {
cpu1, name, cpu2, cpu_to_node(cpu1), cpu_to_node(cpu2));
}
-#define link_mask(_m, c1, c2) \
+#define link_mask(mfunc, c1, c2) \
do { \
- cpumask_set_cpu((c1), cpu_##_m##_mask(c2)); \
- cpumask_set_cpu((c2), cpu_##_m##_mask(c1)); \
+ cpumask_set_cpu((c1), mfunc(c2)); \
+ cpumask_set_cpu((c2), mfunc(c1)); \
} while (0)
static bool match_smt(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o)
cpumask_set_cpu(cpu, cpu_sibling_setup_mask);
if (!has_mp) {
- cpumask_set_cpu(cpu, cpu_sibling_mask(cpu));
+ cpumask_set_cpu(cpu, topology_sibling_cpumask(cpu));
cpumask_set_cpu(cpu, cpu_llc_shared_mask(cpu));
- cpumask_set_cpu(cpu, cpu_core_mask(cpu));
+ cpumask_set_cpu(cpu, topology_core_cpumask(cpu));
c->booted_cores = 1;
return;
}
o = &cpu_data(i);
if ((i == cpu) || (has_smt && match_smt(c, o)))
- link_mask(sibling, cpu, i);
+ link_mask(topology_sibling_cpumask, cpu, i);
if ((i == cpu) || (has_mp && match_llc(c, o)))
- link_mask(llc_shared, cpu, i);
+ link_mask(cpu_llc_shared_mask, cpu, i);
}
/*
* This needs a separate iteration over the cpus because we rely on all
- * cpu_sibling_mask links to be set-up.
+ * topology_sibling_cpumask links to be set-up.
*/
for_each_cpu(i, cpu_sibling_setup_mask) {
o = &cpu_data(i);
if ((i == cpu) || (has_mp && match_die(c, o))) {
- link_mask(core, cpu, i);
+ link_mask(topology_core_cpumask, cpu, i);
/*
* Does this new cpu bringup a new core?
*/
- if (cpumask_weight(cpu_sibling_mask(cpu)) == 1) {
+ if (cpumask_weight(
+ topology_sibling_cpumask(cpu)) == 1) {
/*
* for each core in package, increment
* the booted_cores for this new cpu
*/
- if (cpumask_first(cpu_sibling_mask(i)) == i)
+ if (cpumask_first(
+ topology_sibling_cpumask(i)) == i)
c->booted_cores++;
/*
* increment the core count for all
physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
else
physid_set_mask_of_physid(0, &phys_cpu_present_map);
- cpumask_set_cpu(0, cpu_sibling_mask(0));
- cpumask_set_cpu(0, cpu_core_mask(0));
+ cpumask_set_cpu(0, topology_sibling_cpumask(0));
+ cpumask_set_cpu(0, topology_core_cpumask(0));
}
enum {
int sibling;
struct cpuinfo_x86 *c = &cpu_data(cpu);
- for_each_cpu(sibling, cpu_core_mask(cpu)) {
- cpumask_clear_cpu(cpu, cpu_core_mask(sibling));
+ for_each_cpu(sibling, topology_core_cpumask(cpu)) {
+ cpumask_clear_cpu(cpu, topology_core_cpumask(sibling));
/*/
* last thread sibling in this cpu core going down
*/
- if (cpumask_weight(cpu_sibling_mask(cpu)) == 1)
+ if (cpumask_weight(topology_sibling_cpumask(cpu)) == 1)
cpu_data(sibling).booted_cores--;
}
- for_each_cpu(sibling, cpu_sibling_mask(cpu))
- cpumask_clear_cpu(cpu, cpu_sibling_mask(sibling));
+ for_each_cpu(sibling, topology_sibling_cpumask(cpu))
+ cpumask_clear_cpu(cpu, topology_sibling_cpumask(sibling));
for_each_cpu(sibling, cpu_llc_shared_mask(cpu))
cpumask_clear_cpu(cpu, cpu_llc_shared_mask(sibling));
cpumask_clear(cpu_llc_shared_mask(cpu));
- cpumask_clear(cpu_sibling_mask(cpu));
- cpumask_clear(cpu_core_mask(cpu));
+ cpumask_clear(topology_sibling_cpumask(cpu));
+ cpumask_clear(topology_core_cpumask(cpu));
c->phys_proc_id = 0;
c->cpu_core_id = 0;
cpumask_clear_cpu(cpu, cpu_sibling_setup_mask);
*/
static inline unsigned int loop_timeout(int cpu)
{
- return (cpumask_weight(cpu_core_mask(cpu)) > 1) ? 2 : 20;
+ return (cpumask_weight(topology_core_cpumask(cpu)) > 1) ? 2 : 20;
}
/*
* @from: Source address, in kernel space.
* @n: Number of bytes to copy.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Copy data from kernel space to user space.
*
* @from: Source address, in user space.
* @n: Number of bytes to copy.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Copy data from user space to kernel space.
*
#include <linux/hugetlb.h> /* hstate_index_to_shift */
#include <linux/prefetch.h> /* prefetchw */
#include <linux/context_tracking.h> /* exception_enter(), ... */
+#include <linux/uaccess.h> /* faulthandler_disabled() */
#include <asm/traps.h> /* dotraplinkage, ... */
#include <asm/pgalloc.h> /* pgd_*(), ... */
/*
* If we're in an interrupt, have no user context or are running
- * in an atomic region then we must not take the fault:
+ * in a region with pagefaults disabled then we must not take the fault
*/
- if (unlikely(in_atomic() || !mm)) {
+ if (unlikely(faulthandler_disabled() || !mm)) {
bad_area_nosemaphore(regs, error_code, address);
return;
}
unsigned long vaddr;
int idx, type;
- /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
+ preempt_disable();
pagefault_disable();
if (!PageHighMem(page))
#endif
pagefault_enable();
+ preempt_enable();
}
EXPORT_SYMBOL(__kunmap_atomic);
unsigned long vaddr;
int idx, type;
+ preempt_disable();
pagefault_disable();
type = kmap_atomic_idx_push();
}
pagefault_enable();
+ preempt_enable();
}
EXPORT_SYMBOL_GPL(iounmap_atomic);
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/hardirq.h>
+#include <linux/uaccess.h>
#include <asm/mmu_context.h>
#include <asm/cacheflush.h>
#include <asm/hardirq.h>
-#include <asm/uaccess.h>
#include <asm/pgalloc.h>
DEFINE_PER_CPU(unsigned long, asid_cache) = ASID_USER_FIRST;
/* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
- if (in_atomic() || !mm) {
+ if (faulthandler_disabled() || !mm) {
bad_page_fault(regs, address, SIGSEGV);
return;
}
enum fixed_addresses idx;
unsigned long vaddr;
+ preempt_disable();
pagefault_disable();
if (!PageHighMem(page))
return page_address(page);
}
pagefault_enable();
+ preempt_enable();
}
EXPORT_SYMBOL(__kunmap_atomic);
{
unsigned int ret;
- ret = cpumask_first(topology_thread_cpumask(cpu));
+ ret = cpumask_first(topology_sibling_cpumask(cpu));
if (ret < nr_cpu_ids)
return ret;
mutex_lock(&round_robin_lock);
cpumask_clear(tmp);
for_each_cpu(cpu, pad_busy_cpus)
- cpumask_or(tmp, tmp, topology_thread_cpumask(cpu));
+ cpumask_or(tmp, tmp, topology_sibling_cpumask(cpu));
cpumask_andnot(tmp, cpu_online_mask, tmp);
/* avoid HT sibilings if possible */
if (cpumask_empty(tmp))
define_id_show_func(core_id);
static DEVICE_ATTR_RO(core_id);
-define_siblings_show_func(thread_siblings, thread_cpumask);
+define_siblings_show_func(thread_siblings, sibling_cpumask);
static DEVICE_ATTR_RO(thread_siblings);
static DEVICE_ATTR_RO(thread_siblings_list);
dmi_check_system(sw_any_bug_dmi_table);
if (bios_with_sw_any_bug && !policy_is_shared(policy)) {
policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
- cpumask_copy(policy->cpus, cpu_core_mask(cpu));
+ cpumask_copy(policy->cpus, topology_core_cpumask(cpu));
}
if (check_amd_hwpstate_cpu(cpu) && !acpi_pstate_strict) {
cpumask_clear(policy->cpus);
cpumask_set_cpu(cpu, policy->cpus);
- cpumask_copy(data->freqdomain_cpus, cpu_sibling_mask(cpu));
+ cpumask_copy(data->freqdomain_cpus,
+ topology_sibling_cpumask(cpu));
policy->shared_type = CPUFREQ_SHARED_TYPE_HW;
pr_info_once(PFX "overriding BIOS provided _PSD data\n");
}
unsigned int i;
#ifdef CONFIG_SMP
- cpumask_copy(policy->cpus, cpu_sibling_mask(policy->cpu));
+ cpumask_copy(policy->cpus, topology_sibling_cpumask(policy->cpu));
#endif
/* Errata workaround */
static struct cpufreq_driver cpufreq_amd64_driver;
-#ifndef CONFIG_SMP
-static inline const struct cpumask *cpu_core_mask(int cpu)
-{
- return cpumask_of(0);
-}
-#endif
-
/* Return a frequency in MHz, given an input fid */
static u32 find_freq_from_fid(u32 fid)
{
pr_debug("cfid 0x%x, cvid 0x%x\n", data->currfid, data->currvid);
data->powernow_table = powernow_table;
- if (cpumask_first(cpu_core_mask(data->cpu)) == data->cpu)
+ if (cpumask_first(topology_core_cpumask(data->cpu)) == data->cpu)
print_basics(data);
for (j = 0; j < data->numps; j++)
CPUFREQ_TABLE_END;
data->powernow_table = powernow_table;
- if (cpumask_first(cpu_core_mask(data->cpu)) == data->cpu)
+ if (cpumask_first(topology_core_cpumask(data->cpu)) == data->cpu)
print_basics(data);
/* notify BIOS that we exist */
if (rc != 0)
goto err_out_exit_acpi;
- cpumask_copy(pol->cpus, cpu_core_mask(pol->cpu));
+ cpumask_copy(pol->cpus, topology_core_cpumask(pol->cpu));
data->available_cores = pol->cpus;
/* min/max the cpu is capable of */
/* only run on CPU to be set, or on its sibling */
#ifdef CONFIG_SMP
- cpumask_copy(policy->cpus, cpu_sibling_mask(policy->cpu));
+ cpumask_copy(policy->cpus, topology_sibling_cpumask(policy->cpu));
#endif
policy_cpu = cpumask_any_and(policy->cpus, cpu_online_mask);
int ret;
struct p8_aes_ctx *ctx = crypto_tfm_ctx(tfm);
+ preempt_disable();
pagefault_disable();
enable_kernel_altivec();
ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key);
ret += aes_p8_set_decrypt_key(key, keylen * 8, &ctx->dec_key);
pagefault_enable();
-
+ preempt_enable();
+
ret += crypto_cipher_setkey(ctx->fallback, key, keylen);
return ret;
}
if (in_interrupt()) {
crypto_cipher_encrypt_one(ctx->fallback, dst, src);
} else {
+ preempt_disable();
pagefault_disable();
enable_kernel_altivec();
aes_p8_encrypt(src, dst, &ctx->enc_key);
pagefault_enable();
+ preempt_enable();
}
}
if (in_interrupt()) {
crypto_cipher_decrypt_one(ctx->fallback, dst, src);
} else {
+ preempt_disable();
pagefault_disable();
enable_kernel_altivec();
aes_p8_decrypt(src, dst, &ctx->dec_key);
pagefault_enable();
+ preempt_enable();
}
}
int ret;
struct p8_aes_cbc_ctx *ctx = crypto_tfm_ctx(tfm);
+ preempt_disable();
pagefault_disable();
enable_kernel_altivec();
ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key);
ret += aes_p8_set_decrypt_key(key, keylen * 8, &ctx->dec_key);
pagefault_enable();
+ preempt_enable();
ret += crypto_blkcipher_setkey(ctx->fallback, key, keylen);
return ret;
if (in_interrupt()) {
ret = crypto_blkcipher_encrypt(&fallback_desc, dst, src, nbytes);
} else {
+ preempt_disable();
pagefault_disable();
enable_kernel_altivec();
}
pagefault_enable();
+ preempt_enable();
}
return ret;
if (in_interrupt()) {
ret = crypto_blkcipher_decrypt(&fallback_desc, dst, src, nbytes);
} else {
+ preempt_disable();
pagefault_disable();
enable_kernel_altivec();
}
pagefault_enable();
+ preempt_enable();
}
return ret;
if (keylen != GHASH_KEY_LEN)
return -EINVAL;
+ preempt_disable();
pagefault_disable();
enable_kernel_altivec();
enable_kernel_fp();
gcm_init_p8(ctx->htable, (const u64 *) key);
pagefault_enable();
+ preempt_enable();
return crypto_shash_setkey(ctx->fallback, key, keylen);
}
}
memcpy(dctx->buffer + dctx->bytes, src,
GHASH_DIGEST_SIZE - dctx->bytes);
+ preempt_disable();
pagefault_disable();
enable_kernel_altivec();
enable_kernel_fp();
gcm_ghash_p8(dctx->shash, ctx->htable, dctx->buffer,
GHASH_DIGEST_SIZE);
pagefault_enable();
+ preempt_enable();
src += GHASH_DIGEST_SIZE - dctx->bytes;
srclen -= GHASH_DIGEST_SIZE - dctx->bytes;
dctx->bytes = 0;
}
len = srclen & ~(GHASH_DIGEST_SIZE - 1);
if (len) {
+ preempt_disable();
pagefault_disable();
enable_kernel_altivec();
enable_kernel_fp();
gcm_ghash_p8(dctx->shash, ctx->htable, src, len);
pagefault_enable();
+ preempt_enable();
src += len;
srclen -= len;
}
if (dctx->bytes) {
for (i = dctx->bytes; i < GHASH_DIGEST_SIZE; i++)
dctx->buffer[i] = 0;
+ preempt_disable();
pagefault_disable();
enable_kernel_altivec();
enable_kernel_fp();
gcm_ghash_p8(dctx->shash, ctx->htable, dctx->buffer,
GHASH_DIGEST_SIZE);
pagefault_enable();
+ preempt_enable();
dctx->bytes = 0;
}
memcpy(out, dctx->shash, GHASH_DIGEST_SIZE);
#include "i915_trace.h"
#include "intel_drv.h"
#include <linux/dma_remapping.h>
+#include <linux/uaccess.h>
#define __EXEC_OBJECT_HAS_PIN (1<<31)
#define __EXEC_OBJECT_HAS_FENCE (1<<30)
}
/* We can't wait for rendering with pagefaults disabled */
- if (obj->active && in_atomic())
+ if (obj->active && pagefault_disabled())
return -EFAULT;
if (use_cpu_reloc(obj))
#define TO_ATTR_NO(cpu) (TO_CORE_ID(cpu) + BASE_SYSFS_ATTR_NO)
#ifdef CONFIG_SMP
-#define for_each_sibling(i, cpu) for_each_cpu(i, cpu_sibling_mask(cpu))
+#define for_each_sibling(i, cpu) \
+ for_each_cpu(i, topology_sibling_cpumask(cpu))
#else
#define for_each_sibling(i, cpu) for (i = 0; false; )
#endif
if (!cpumask_test_cpu(cpu, thread_mask)) {
++count;
cpumask_or(thread_mask, thread_mask,
- topology_thread_cpumask(cpu));
+ topology_sibling_cpumask(cpu));
}
}
/* return cpumask of HTs in the same core */
static void cfs_cpu_ht_siblings(int cpu, cpumask_t *mask)
{
- cpumask_copy(mask, topology_thread_cpumask(cpu));
+ cpumask_copy(mask, topology_sibling_cpumask(cpu));
}
static void cfs_node_to_cpumask(int node, cpumask_t *mask)
* there are.
*/
/* weight is # of HTs */
- if (cpumask_weight(topology_thread_cpumask(0)) > 1) {
+ if (cpumask_weight(topology_sibling_cpumask(0)) > 1) {
/* depress thread factor for hyper-thread */
factor = factor - (factor >> 1) + (factor >> 3);
}
init_waitqueue_head(&ptlrpc_hr.hr_waitq);
- weight = cpumask_weight(topology_thread_cpumask(0));
+ weight = cpumask_weight(topology_sibling_cpumask(0));
cfs_percpt_for_each(hrp, i, ptlrpc_hr.hr_partitions) {
hrp->hrp_cpt = i;
#ifndef CONFIG_SMP
/*
* The following implementation only for uniprocessor machines.
- * For UP, it's relies on the fact that pagefault_disable() also disables
- * preemption to ensure mutual exclusion.
+ * It relies on preempt_disable() ensuring mutual exclusion.
*
*/
if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
oparg = 1 << oparg;
+ preempt_disable();
pagefault_disable();
ret = -EFAULT;
out_pagefault_enable:
pagefault_enable();
+ preempt_enable();
if (ret == 0) {
switch (cmp) {
{
u32 val;
+ preempt_disable();
if (unlikely(get_user(val, uaddr) != 0))
return -EFAULT;
return -EFAULT;
*uval = val;
+ preempt_enable();
return 0;
}
#define _LINUX_BH_H
#include <linux/preempt.h>
-#include <linux/preempt_mask.h>
#ifdef CONFIG_TRACE_IRQFLAGS
extern void __local_bh_disable_ip(unsigned long ip, unsigned int cnt);
#ifndef LINUX_HARDIRQ_H
#define LINUX_HARDIRQ_H
-#include <linux/preempt_mask.h>
+#include <linux/preempt.h>
#include <linux/lockdep.h>
#include <linux/ftrace_irq.h>
#include <linux/vtime.h>
static inline void *kmap_atomic(struct page *page)
{
+ preempt_disable();
pagefault_disable();
return page_address(page);
}
static inline void __kunmap_atomic(void *addr)
{
pagefault_enable();
+ preempt_enable();
}
#define kmap_atomic_pfn(pfn) kmap_atomic(pfn_to_page(pfn))
.cpu_timers = INIT_CPU_TIMERS(sig.cpu_timers), \
.rlim = INIT_RLIMITS, \
.cputimer = { \
- .cputime = INIT_CPUTIME, \
- .running = 0, \
- .lock = __RAW_SPIN_LOCK_UNLOCKED(sig.cputimer.lock), \
+ .cputime_atomic = INIT_CPUTIME_ATOMIC, \
+ .running = 0, \
}, \
.cred_guard_mutex = \
__MUTEX_INITIALIZER(sig.cred_guard_mutex), \
io_mapping_map_atomic_wc(struct io_mapping *mapping,
unsigned long offset)
{
+ preempt_disable();
pagefault_disable();
return ((char __force __iomem *) mapping) + offset;
}
io_mapping_unmap_atomic(void __iomem *vaddr)
{
pagefault_enable();
+ preempt_enable();
}
/* Non-atomic map/unmap */
#if defined(CONFIG_MMU) && \
(defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP))
-void might_fault(void);
+#define might_fault() __might_fault(__FILE__, __LINE__)
+void __might_fault(const char *file, int line);
#else
static inline void might_fault(void) { }
#endif
#include <linux/list.h>
/*
- * We use the MSB mostly because its available; see <linux/preempt_mask.h> for
- * the other bits -- can't include that header due to inclusion hell.
+ * We put the hardirq and softirq counter into the preemption
+ * counter. The bitmask has the following meaning:
+ *
+ * - bits 0-7 are the preemption count (max preemption depth: 256)
+ * - bits 8-15 are the softirq count (max # of softirqs: 256)
+ *
+ * The hardirq count could in theory be the same as the number of
+ * interrupts in the system, but we run all interrupt handlers with
+ * interrupts disabled, so we cannot have nesting interrupts. Though
+ * there are a few palaeontologic drivers which reenable interrupts in
+ * the handler, so we need more than one bit here.
+ *
+ * PREEMPT_MASK: 0x000000ff
+ * SOFTIRQ_MASK: 0x0000ff00
+ * HARDIRQ_MASK: 0x000f0000
+ * NMI_MASK: 0x00100000
+ * PREEMPT_ACTIVE: 0x00200000
+ * PREEMPT_NEED_RESCHED: 0x80000000
*/
+#define PREEMPT_BITS 8
+#define SOFTIRQ_BITS 8
+#define HARDIRQ_BITS 4
+#define NMI_BITS 1
+
+#define PREEMPT_SHIFT 0
+#define SOFTIRQ_SHIFT (PREEMPT_SHIFT + PREEMPT_BITS)
+#define HARDIRQ_SHIFT (SOFTIRQ_SHIFT + SOFTIRQ_BITS)
+#define NMI_SHIFT (HARDIRQ_SHIFT + HARDIRQ_BITS)
+
+#define __IRQ_MASK(x) ((1UL << (x))-1)
+
+#define PREEMPT_MASK (__IRQ_MASK(PREEMPT_BITS) << PREEMPT_SHIFT)
+#define SOFTIRQ_MASK (__IRQ_MASK(SOFTIRQ_BITS) << SOFTIRQ_SHIFT)
+#define HARDIRQ_MASK (__IRQ_MASK(HARDIRQ_BITS) << HARDIRQ_SHIFT)
+#define NMI_MASK (__IRQ_MASK(NMI_BITS) << NMI_SHIFT)
+
+#define PREEMPT_OFFSET (1UL << PREEMPT_SHIFT)
+#define SOFTIRQ_OFFSET (1UL << SOFTIRQ_SHIFT)
+#define HARDIRQ_OFFSET (1UL << HARDIRQ_SHIFT)
+#define NMI_OFFSET (1UL << NMI_SHIFT)
+
+#define SOFTIRQ_DISABLE_OFFSET (2 * SOFTIRQ_OFFSET)
+
+#define PREEMPT_ACTIVE_BITS 1
+#define PREEMPT_ACTIVE_SHIFT (NMI_SHIFT + NMI_BITS)
+#define PREEMPT_ACTIVE (__IRQ_MASK(PREEMPT_ACTIVE_BITS) << PREEMPT_ACTIVE_SHIFT)
+
+/* We use the MSB mostly because its available */
#define PREEMPT_NEED_RESCHED 0x80000000
+/* preempt_count() and related functions, depends on PREEMPT_NEED_RESCHED */
#include <asm/preempt.h>
+#define hardirq_count() (preempt_count() & HARDIRQ_MASK)
+#define softirq_count() (preempt_count() & SOFTIRQ_MASK)
+#define irq_count() (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_MASK \
+ | NMI_MASK))
+
+/*
+ * Are we doing bottom half or hardware interrupt processing?
+ * Are we in a softirq context? Interrupt context?
+ * in_softirq - Are we currently processing softirq or have bh disabled?
+ * in_serving_softirq - Are we currently processing softirq?
+ */
+#define in_irq() (hardirq_count())
+#define in_softirq() (softirq_count())
+#define in_interrupt() (irq_count())
+#define in_serving_softirq() (softirq_count() & SOFTIRQ_OFFSET)
+
+/*
+ * Are we in NMI context?
+ */
+#define in_nmi() (preempt_count() & NMI_MASK)
+
+#if defined(CONFIG_PREEMPT_COUNT)
+# define PREEMPT_DISABLE_OFFSET 1
+#else
+# define PREEMPT_DISABLE_OFFSET 0
+#endif
+
+/*
+ * The preempt_count offset needed for things like:
+ *
+ * spin_lock_bh()
+ *
+ * Which need to disable both preemption (CONFIG_PREEMPT_COUNT) and
+ * softirqs, such that unlock sequences of:
+ *
+ * spin_unlock();
+ * local_bh_enable();
+ *
+ * Work as expected.
+ */
+#define SOFTIRQ_LOCK_OFFSET (SOFTIRQ_DISABLE_OFFSET + PREEMPT_DISABLE_OFFSET)
+
+/*
+ * Are we running in atomic context? WARNING: this macro cannot
+ * always detect atomic context; in particular, it cannot know about
+ * held spinlocks in non-preemptible kernels. Thus it should not be
+ * used in the general case to determine whether sleeping is possible.
+ * Do not use in_atomic() in driver code.
+ */
+#define in_atomic() (preempt_count() != 0)
+
+/*
+ * Check whether we were atomic before we did preempt_disable():
+ * (used by the scheduler)
+ */
+#define in_atomic_preempt_off() \
+ ((preempt_count() & ~PREEMPT_ACTIVE) != PREEMPT_DISABLE_OFFSET)
+
#if defined(CONFIG_DEBUG_PREEMPT) || defined(CONFIG_PREEMPT_TRACER)
extern void preempt_count_add(int val);
extern void preempt_count_sub(int val);
#define preempt_count_inc() preempt_count_add(1)
#define preempt_count_dec() preempt_count_sub(1)
+#define preempt_active_enter() \
+do { \
+ preempt_count_add(PREEMPT_ACTIVE + PREEMPT_DISABLE_OFFSET); \
+ barrier(); \
+} while (0)
+
+#define preempt_active_exit() \
+do { \
+ barrier(); \
+ preempt_count_sub(PREEMPT_ACTIVE + PREEMPT_DISABLE_OFFSET); \
+} while (0)
+
#ifdef CONFIG_PREEMPT_COUNT
#define preempt_disable() \
#define preempt_enable_no_resched() sched_preempt_enable_no_resched()
+#define preemptible() (preempt_count() == 0 && !irqs_disabled())
+
#ifdef CONFIG_PREEMPT
#define preempt_enable() \
do { \
#define preempt_disable_notrace() barrier()
#define preempt_enable_no_resched_notrace() barrier()
#define preempt_enable_notrace() barrier()
+#define preemptible() 0
#endif /* CONFIG_PREEMPT_COUNT */
+++ /dev/null
-#ifndef LINUX_PREEMPT_MASK_H
-#define LINUX_PREEMPT_MASK_H
-
-#include <linux/preempt.h>
-
-/*
- * We put the hardirq and softirq counter into the preemption
- * counter. The bitmask has the following meaning:
- *
- * - bits 0-7 are the preemption count (max preemption depth: 256)
- * - bits 8-15 are the softirq count (max # of softirqs: 256)
- *
- * The hardirq count could in theory be the same as the number of
- * interrupts in the system, but we run all interrupt handlers with
- * interrupts disabled, so we cannot have nesting interrupts. Though
- * there are a few palaeontologic drivers which reenable interrupts in
- * the handler, so we need more than one bit here.
- *
- * PREEMPT_MASK: 0x000000ff
- * SOFTIRQ_MASK: 0x0000ff00
- * HARDIRQ_MASK: 0x000f0000
- * NMI_MASK: 0x00100000
- * PREEMPT_ACTIVE: 0x00200000
- */
-#define PREEMPT_BITS 8
-#define SOFTIRQ_BITS 8
-#define HARDIRQ_BITS 4
-#define NMI_BITS 1
-
-#define PREEMPT_SHIFT 0
-#define SOFTIRQ_SHIFT (PREEMPT_SHIFT + PREEMPT_BITS)
-#define HARDIRQ_SHIFT (SOFTIRQ_SHIFT + SOFTIRQ_BITS)
-#define NMI_SHIFT (HARDIRQ_SHIFT + HARDIRQ_BITS)
-
-#define __IRQ_MASK(x) ((1UL << (x))-1)
-
-#define PREEMPT_MASK (__IRQ_MASK(PREEMPT_BITS) << PREEMPT_SHIFT)
-#define SOFTIRQ_MASK (__IRQ_MASK(SOFTIRQ_BITS) << SOFTIRQ_SHIFT)
-#define HARDIRQ_MASK (__IRQ_MASK(HARDIRQ_BITS) << HARDIRQ_SHIFT)
-#define NMI_MASK (__IRQ_MASK(NMI_BITS) << NMI_SHIFT)
-
-#define PREEMPT_OFFSET (1UL << PREEMPT_SHIFT)
-#define SOFTIRQ_OFFSET (1UL << SOFTIRQ_SHIFT)
-#define HARDIRQ_OFFSET (1UL << HARDIRQ_SHIFT)
-#define NMI_OFFSET (1UL << NMI_SHIFT)
-
-#define SOFTIRQ_DISABLE_OFFSET (2 * SOFTIRQ_OFFSET)
-
-#define PREEMPT_ACTIVE_BITS 1
-#define PREEMPT_ACTIVE_SHIFT (NMI_SHIFT + NMI_BITS)
-#define PREEMPT_ACTIVE (__IRQ_MASK(PREEMPT_ACTIVE_BITS) << PREEMPT_ACTIVE_SHIFT)
-
-#define hardirq_count() (preempt_count() & HARDIRQ_MASK)
-#define softirq_count() (preempt_count() & SOFTIRQ_MASK)
-#define irq_count() (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_MASK \
- | NMI_MASK))
-
-/*
- * Are we doing bottom half or hardware interrupt processing?
- * Are we in a softirq context? Interrupt context?
- * in_softirq - Are we currently processing softirq or have bh disabled?
- * in_serving_softirq - Are we currently processing softirq?
- */
-#define in_irq() (hardirq_count())
-#define in_softirq() (softirq_count())
-#define in_interrupt() (irq_count())
-#define in_serving_softirq() (softirq_count() & SOFTIRQ_OFFSET)
-
-/*
- * Are we in NMI context?
- */
-#define in_nmi() (preempt_count() & NMI_MASK)
-
-#if defined(CONFIG_PREEMPT_COUNT)
-# define PREEMPT_CHECK_OFFSET 1
-#else
-# define PREEMPT_CHECK_OFFSET 0
-#endif
-
-/*
- * The preempt_count offset needed for things like:
- *
- * spin_lock_bh()
- *
- * Which need to disable both preemption (CONFIG_PREEMPT_COUNT) and
- * softirqs, such that unlock sequences of:
- *
- * spin_unlock();
- * local_bh_enable();
- *
- * Work as expected.
- */
-#define SOFTIRQ_LOCK_OFFSET (SOFTIRQ_DISABLE_OFFSET + PREEMPT_CHECK_OFFSET)
-
-/*
- * Are we running in atomic context? WARNING: this macro cannot
- * always detect atomic context; in particular, it cannot know about
- * held spinlocks in non-preemptible kernels. Thus it should not be
- * used in the general case to determine whether sleeping is possible.
- * Do not use in_atomic() in driver code.
- */
-#define in_atomic() ((preempt_count() & ~PREEMPT_ACTIVE) != 0)
-
-/*
- * Check whether we were atomic before we did preempt_disable():
- * (used by the scheduler, *after* releasing the kernel lock)
- */
-#define in_atomic_preempt_off() \
- ((preempt_count() & ~PREEMPT_ACTIVE) != PREEMPT_CHECK_OFFSET)
-
-#ifdef CONFIG_PREEMPT_COUNT
-# define preemptible() (preempt_count() == 0 && !irqs_disabled())
-#else
-# define preemptible() 0
-#endif
-
-#endif /* LINUX_PREEMPT_MASK_H */
#include <linux/errno.h>
#include <linux/nodemask.h>
#include <linux/mm_types.h>
-#include <linux/preempt_mask.h>
+#include <linux/preempt.h>
#include <asm/page.h>
#include <asm/ptrace.h>
extern void get_iowait_load(unsigned long *nr_waiters, unsigned long *load);
extern void calc_global_load(unsigned long ticks);
+
+#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
extern void update_cpu_load_nohz(void);
+#else
+static inline void update_cpu_load_nohz(void) { }
+#endif
extern unsigned long get_parent_ip(unsigned long addr);
#define TASK_WAKEKILL 128
#define TASK_WAKING 256
#define TASK_PARKED 512
-#define TASK_STATE_MAX 1024
+#define TASK_NOLOAD 1024
+#define TASK_STATE_MAX 2048
-#define TASK_STATE_TO_CHAR_STR "RSDTtXZxKWP"
+#define TASK_STATE_TO_CHAR_STR "RSDTtXZxKWPN"
extern char ___assert_task_state[1 - 2*!!(
sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1)];
#define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED)
#define TASK_TRACED (TASK_WAKEKILL | __TASK_TRACED)
+#define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
+
/* Convenience macros for the sake of wake_up */
#define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
#define TASK_ALL (TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
#define task_contributes_to_load(task) \
((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
- (task->flags & PF_FROZEN) == 0)
+ (task->flags & PF_FROZEN) == 0 && \
+ (task->state & TASK_NOLOAD) == 0)
#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
.sum_exec_runtime = 0, \
}
+/*
+ * This is the atomic variant of task_cputime, which can be used for
+ * storing and updating task_cputime statistics without locking.
+ */
+struct task_cputime_atomic {
+ atomic64_t utime;
+ atomic64_t stime;
+ atomic64_t sum_exec_runtime;
+};
+
+#define INIT_CPUTIME_ATOMIC \
+ (struct task_cputime_atomic) { \
+ .utime = ATOMIC64_INIT(0), \
+ .stime = ATOMIC64_INIT(0), \
+ .sum_exec_runtime = ATOMIC64_INIT(0), \
+ }
+
#ifdef CONFIG_PREEMPT_COUNT
#define PREEMPT_DISABLED (1 + PREEMPT_ENABLED)
#else
/**
* struct thread_group_cputimer - thread group interval timer counts
- * @cputime: thread group interval timers.
+ * @cputime_atomic: atomic thread group interval timers.
* @running: non-zero when there are timers running and
* @cputime receives updates.
- * @lock: lock for fields in this struct.
*
* This structure contains the version of task_cputime, above, that is
* used for thread group CPU timer calculations.
*/
struct thread_group_cputimer {
- struct task_cputime cputime;
+ struct task_cputime_atomic cputime_atomic;
int running;
- raw_spinlock_t lock;
};
#include <linux/rwsem.h>
#define SCHED_CAPACITY_SHIFT 10
#define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT)
+/*
+ * Wake-queues are lists of tasks with a pending wakeup, whose
+ * callers have already marked the task as woken internally,
+ * and can thus carry on. A common use case is being able to
+ * do the wakeups once the corresponding user lock as been
+ * released.
+ *
+ * We hold reference to each task in the list across the wakeup,
+ * thus guaranteeing that the memory is still valid by the time
+ * the actual wakeups are performed in wake_up_q().
+ *
+ * One per task suffices, because there's never a need for a task to be
+ * in two wake queues simultaneously; it is forbidden to abandon a task
+ * in a wake queue (a call to wake_up_q() _must_ follow), so if a task is
+ * already in a wake queue, the wakeup will happen soon and the second
+ * waker can just skip it.
+ *
+ * The WAKE_Q macro declares and initializes the list head.
+ * wake_up_q() does NOT reinitialize the list; it's expected to be
+ * called near the end of a function, where the fact that the queue is
+ * not used again will be easy to see by inspection.
+ *
+ * Note that this can cause spurious wakeups. schedule() callers
+ * must ensure the call is done inside a loop, confirming that the
+ * wakeup condition has in fact occurred.
+ */
+struct wake_q_node {
+ struct wake_q_node *next;
+};
+
+struct wake_q_head {
+ struct wake_q_node *first;
+ struct wake_q_node **lastp;
+};
+
+#define WAKE_Q_TAIL ((struct wake_q_node *) 0x01)
+
+#define WAKE_Q(name) \
+ struct wake_q_head name = { WAKE_Q_TAIL, &name.first }
+
+extern void wake_q_add(struct wake_q_head *head,
+ struct task_struct *task);
+extern void wake_up_q(struct wake_q_head *head);
+
/*
* sched-domains (multiprocessor balancing) declarations:
*/
int rcu_read_lock_nesting;
union rcu_special rcu_read_unlock_special;
struct list_head rcu_node_entry;
-#endif /* #ifdef CONFIG_PREEMPT_RCU */
-#ifdef CONFIG_PREEMPT_RCU
struct rcu_node *rcu_blocked_node;
#endif /* #ifdef CONFIG_PREEMPT_RCU */
#ifdef CONFIG_TASKS_RCU
int exit_state;
int exit_code, exit_signal;
int pdeath_signal; /* The signal sent when the parent dies */
- unsigned int jobctl; /* JOBCTL_*, siglock protected */
+ unsigned long jobctl; /* JOBCTL_*, siglock protected */
/* Used for emulating ABI behavior of previous Linux versions */
unsigned int personality;
/* Protection of the PI data structures: */
raw_spinlock_t pi_lock;
+ struct wake_q_node wake_q;
+
#ifdef CONFIG_RT_MUTEXES
/* PI waiters blocked on a rt_mutex held by this task */
struct rb_root pi_waiters;
#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
unsigned long task_state_change;
#endif
+ int pagefault_disabled;
};
/* Future-safe accessor for struct task_struct's cpus_allowed. */
#define JOBCTL_TRAPPING_BIT 21 /* switching to TRACED */
#define JOBCTL_LISTENING_BIT 22 /* ptracer is listening for events */
-#define JOBCTL_STOP_DEQUEUED (1 << JOBCTL_STOP_DEQUEUED_BIT)
-#define JOBCTL_STOP_PENDING (1 << JOBCTL_STOP_PENDING_BIT)
-#define JOBCTL_STOP_CONSUME (1 << JOBCTL_STOP_CONSUME_BIT)
-#define JOBCTL_TRAP_STOP (1 << JOBCTL_TRAP_STOP_BIT)
-#define JOBCTL_TRAP_NOTIFY (1 << JOBCTL_TRAP_NOTIFY_BIT)
-#define JOBCTL_TRAPPING (1 << JOBCTL_TRAPPING_BIT)
-#define JOBCTL_LISTENING (1 << JOBCTL_LISTENING_BIT)
+#define JOBCTL_STOP_DEQUEUED (1UL << JOBCTL_STOP_DEQUEUED_BIT)
+#define JOBCTL_STOP_PENDING (1UL << JOBCTL_STOP_PENDING_BIT)
+#define JOBCTL_STOP_CONSUME (1UL << JOBCTL_STOP_CONSUME_BIT)
+#define JOBCTL_TRAP_STOP (1UL << JOBCTL_TRAP_STOP_BIT)
+#define JOBCTL_TRAP_NOTIFY (1UL << JOBCTL_TRAP_NOTIFY_BIT)
+#define JOBCTL_TRAPPING (1UL << JOBCTL_TRAPPING_BIT)
+#define JOBCTL_LISTENING (1UL << JOBCTL_LISTENING_BIT)
#define JOBCTL_TRAP_MASK (JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY)
#define JOBCTL_PENDING_MASK (JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK)
extern bool task_set_jobctl_pending(struct task_struct *task,
- unsigned int mask);
+ unsigned long mask);
extern void task_clear_jobctl_trapping(struct task_struct *task);
extern void task_clear_jobctl_pending(struct task_struct *task,
- unsigned int mask);
+ unsigned long mask);
static inline void rcu_copy_process(struct task_struct *p)
{
void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
-static inline void thread_group_cputime_init(struct signal_struct *sig)
-{
- raw_spin_lock_init(&sig->cputimer.lock);
-}
-
/*
* Reevaluate whether the task has signals pending delivery.
* Wake the task if so.
static inline unsigned long task_rlimit(const struct task_struct *tsk,
unsigned int limit)
{
- return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_cur);
+ return READ_ONCE(tsk->signal->rlim[limit].rlim_cur);
}
static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
unsigned int limit)
{
- return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_max);
+ return READ_ONCE(tsk->signal->rlim[limit].rlim_max);
}
static inline unsigned long rlimit(unsigned int limit)
#ifndef topology_core_id
#define topology_core_id(cpu) ((void)(cpu), 0)
#endif
-#ifndef topology_thread_cpumask
-#define topology_thread_cpumask(cpu) cpumask_of(cpu)
+#ifndef topology_sibling_cpumask
+#define topology_sibling_cpumask(cpu) cpumask_of(cpu)
#endif
#ifndef topology_core_cpumask
#define topology_core_cpumask(cpu) cpumask_of(cpu)
#ifdef CONFIG_SCHED_SMT
static inline const struct cpumask *cpu_smt_mask(int cpu)
{
- return topology_thread_cpumask(cpu);
+ return topology_sibling_cpumask(cpu);
}
#endif
#ifndef __LINUX_UACCESS_H__
#define __LINUX_UACCESS_H__
-#include <linux/preempt.h>
+#include <linux/sched.h>
#include <asm/uaccess.h>
+static __always_inline void pagefault_disabled_inc(void)
+{
+ current->pagefault_disabled++;
+}
+
+static __always_inline void pagefault_disabled_dec(void)
+{
+ current->pagefault_disabled--;
+ WARN_ON(current->pagefault_disabled < 0);
+}
+
/*
- * These routines enable/disable the pagefault handler in that
- * it will not take any locks and go straight to the fixup table.
+ * These routines enable/disable the pagefault handler. If disabled, it will
+ * not take any locks and go straight to the fixup table.
*
- * They have great resemblance to the preempt_disable/enable calls
- * and in fact they are identical; this is because currently there is
- * no other way to make the pagefault handlers do this. So we do
- * disable preemption but we don't necessarily care about that.
+ * User access methods will not sleep when called from a pagefault_disabled()
+ * environment.
*/
static inline void pagefault_disable(void)
{
- preempt_count_inc();
+ pagefault_disabled_inc();
/*
* make sure to have issued the store before a pagefault
* can hit.
static inline void pagefault_enable(void)
{
-#ifndef CONFIG_PREEMPT
/*
* make sure to issue those last loads/stores before enabling
* the pagefault handler again.
*/
barrier();
- preempt_count_dec();
-#else
- preempt_enable();
-#endif
+ pagefault_disabled_dec();
}
+/*
+ * Is the pagefault handler disabled? If so, user access methods will not sleep.
+ */
+#define pagefault_disabled() (current->pagefault_disabled != 0)
+
+/*
+ * The pagefault handler is in general disabled by pagefault_disable() or
+ * when in irq context (via in_atomic()).
+ *
+ * This function should only be used by the fault handlers. Other users should
+ * stick to pagefault_disabled().
+ * Please NEVER use preempt_disable() to disable the fault handler. With
+ * !CONFIG_PREEMPT_COUNT, this is like a NOP. So the handler won't be disabled.
+ * in_atomic() will report different values based on !CONFIG_PREEMPT_COUNT.
+ */
+#define faulthandler_disabled() (pagefault_disabled() || in_atomic())
+
#ifndef ARCH_HAS_NOCACHE_UACCESS
static inline unsigned long __copy_from_user_inatomic_nocache(void *to,
* on that signal.
*/
static inline int
-wait_on_bit(void *word, int bit, unsigned mode)
+wait_on_bit(unsigned long *word, int bit, unsigned mode)
{
might_sleep();
if (!test_bit(bit, word))
* on that signal.
*/
static inline int
-wait_on_bit_io(void *word, int bit, unsigned mode)
+wait_on_bit_io(unsigned long *word, int bit, unsigned mode)
{
might_sleep();
if (!test_bit(bit, word))
* received a signal and the mode permitted wakeup on that signal.
*/
static inline int
-wait_on_bit_timeout(void *word, int bit, unsigned mode, unsigned long timeout)
+wait_on_bit_timeout(unsigned long *word, int bit, unsigned mode,
+ unsigned long timeout)
{
might_sleep();
if (!test_bit(bit, word))
* on that signal.
*/
static inline int
-wait_on_bit_action(void *word, int bit, wait_bit_action_f *action, unsigned mode)
+wait_on_bit_action(unsigned long *word, int bit, wait_bit_action_f *action,
+ unsigned mode)
{
might_sleep();
if (!test_bit(bit, word))
* the @mode allows that signal to wake the process.
*/
static inline int
-wait_on_bit_lock(void *word, int bit, unsigned mode)
+wait_on_bit_lock(unsigned long *word, int bit, unsigned mode)
{
might_sleep();
if (!test_and_set_bit(bit, word))
* the @mode allows that signal to wake the process.
*/
static inline int
-wait_on_bit_lock_io(void *word, int bit, unsigned mode)
+wait_on_bit_lock_io(unsigned long *word, int bit, unsigned mode)
{
might_sleep();
if (!test_and_set_bit(bit, word))
* the @mode allows that signal to wake the process.
*/
static inline int
-wait_on_bit_lock_action(void *word, int bit, wait_bit_action_f *action, unsigned mode)
+wait_on_bit_lock_action(unsigned long *word, int bit, wait_bit_action_f *action,
+ unsigned mode)
{
might_sleep();
if (!test_and_set_bit(bit, word))
__print_flags(__entry->prev_state & (TASK_STATE_MAX-1), "|",
{ 1, "S"} , { 2, "D" }, { 4, "T" }, { 8, "t" },
{ 16, "Z" }, { 32, "X" }, { 64, "x" },
- { 128, "K" }, { 256, "W" }, { 512, "P" }) : "R",
+ { 128, "K" }, { 256, "W" }, { 512, "P" },
+ { 1024, "N" }) : "R",
__entry->prev_state & TASK_STATE_MAX ? "+" : "",
__entry->next_comm, __entry->next_pid, __entry->next_prio)
);
#define RECV 1
#define STATE_NONE 0
-#define STATE_PENDING 1
-#define STATE_READY 2
+#define STATE_READY 1
struct posix_msg_tree_node {
struct rb_node rb_node;
wq_add(info, sr, ewp);
for (;;) {
- set_current_state(TASK_INTERRUPTIBLE);
+ __set_current_state(TASK_INTERRUPTIBLE);
spin_unlock(&info->lock);
time = schedule_hrtimeout_range_clock(timeout, 0,
HRTIMER_MODE_ABS, CLOCK_REALTIME);
- while (ewp->state == STATE_PENDING)
- cpu_relax();
-
if (ewp->state == STATE_READY) {
retval = 0;
goto out;
* list of waiting receivers. A sender checks that list before adding the new
* message into the message array. If there is a waiting receiver, then it
* bypasses the message array and directly hands the message over to the
- * receiver.
- * The receiver accepts the message and returns without grabbing the queue
- * spinlock. Therefore an intermediate STATE_PENDING state and memory barriers
- * are necessary. The same algorithm is used for sysv semaphores, see
- * ipc/sem.c for more details.
+ * receiver. The receiver accepts the message and returns without grabbing the
+ * queue spinlock:
+ *
+ * - Set pointer to message.
+ * - Queue the receiver task for later wakeup (without the info->lock).
+ * - Update its state to STATE_READY. Now the receiver can continue.
+ * - Wake up the process after the lock is dropped. Should the process wake up
+ * before this wakeup (due to a timeout or a signal) it will either see
+ * STATE_READY and continue or acquire the lock to check the state again.
*
* The same algorithm is used for senders.
*/
/* pipelined_send() - send a message directly to the task waiting in
* sys_mq_timedreceive() (without inserting message into a queue).
*/
-static inline void pipelined_send(struct mqueue_inode_info *info,
+static inline void pipelined_send(struct wake_q_head *wake_q,
+ struct mqueue_inode_info *info,
struct msg_msg *message,
struct ext_wait_queue *receiver)
{
receiver->msg = message;
list_del(&receiver->list);
- receiver->state = STATE_PENDING;
- wake_up_process(receiver->task);
- smp_wmb();
+ wake_q_add(wake_q, receiver->task);
+ /*
+ * Rely on the implicit cmpxchg barrier from wake_q_add such
+ * that we can ensure that updating receiver->state is the last
+ * write operation: As once set, the receiver can continue,
+ * and if we don't have the reference count from the wake_q,
+ * yet, at that point we can later have a use-after-free
+ * condition and bogus wakeup.
+ */
receiver->state = STATE_READY;
}
/* pipelined_receive() - if there is task waiting in sys_mq_timedsend()
* gets its message and put to the queue (we have one free place for sure). */
-static inline void pipelined_receive(struct mqueue_inode_info *info)
+static inline void pipelined_receive(struct wake_q_head *wake_q,
+ struct mqueue_inode_info *info)
{
struct ext_wait_queue *sender = wq_get_first_waiter(info, SEND);
}
if (msg_insert(sender->msg, info))
return;
+
list_del(&sender->list);
- sender->state = STATE_PENDING;
- wake_up_process(sender->task);
- smp_wmb();
+ wake_q_add(wake_q, sender->task);
sender->state = STATE_READY;
}
struct timespec ts;
struct posix_msg_tree_node *new_leaf = NULL;
int ret = 0;
+ WAKE_Q(wake_q);
if (u_abs_timeout) {
int res = prepare_timeout(u_abs_timeout, &expires, &ts);
} else {
receiver = wq_get_first_waiter(info, RECV);
if (receiver) {
- pipelined_send(info, msg_ptr, receiver);
+ pipelined_send(&wake_q, info, msg_ptr, receiver);
} else {
/* adds message to the queue */
ret = msg_insert(msg_ptr, info);
}
out_unlock:
spin_unlock(&info->lock);
+ wake_up_q(&wake_q);
out_free:
if (ret)
free_msg(msg_ptr);
msg_ptr = wait.msg;
}
} else {
+ WAKE_Q(wake_q);
+
msg_ptr = msg_get(info);
inode->i_atime = inode->i_mtime = inode->i_ctime =
CURRENT_TIME;
/* There is now free space in queue. */
- pipelined_receive(info);
+ pipelined_receive(&wake_q, info);
spin_unlock(&info->lock);
+ wake_up_q(&wake_q);
ret = 0;
}
if (ret == 0) {
{
unsigned long cpu_limit;
- /* Thread group counters. */
- thread_group_cputime_init(sig);
-
- cpu_limit = ACCESS_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur);
+ cpu_limit = READ_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur);
if (cpu_limit != RLIM_INFINITY) {
sig->cputime_expires.prof_exp = secs_to_cputime(cpu_limit);
sig->cputimer.running = 1;
p->hardirq_context = 0;
p->softirq_context = 0;
#endif
+
+ p->pagefault_disabled = 0;
+
#ifdef CONFIG_LOCKDEP
p->lockdep_depth = 0; /* no locks held yet */
p->curr_chain_key = 0;
/*
* The hash bucket lock must be held when this is called.
- * Afterwards, the futex_q must not be accessed.
+ * Afterwards, the futex_q must not be accessed. Callers
+ * must ensure to later call wake_up_q() for the actual
+ * wakeups to occur.
*/
-static void wake_futex(struct futex_q *q)
+static void mark_wake_futex(struct wake_q_head *wake_q, struct futex_q *q)
{
struct task_struct *p = q->task;
return;
/*
- * We set q->lock_ptr = NULL _before_ we wake up the task. If
- * a non-futex wake up happens on another CPU then the task
- * might exit and p would dereference a non-existing task
- * struct. Prevent this by holding a reference on p across the
- * wake up.
+ * Queue the task for later wakeup for after we've released
+ * the hb->lock. wake_q_add() grabs reference to p.
*/
- get_task_struct(p);
-
+ wake_q_add(wake_q, p);
__unqueue_futex(q);
/*
* The waiting task can free the futex_q as soon as
*/
smp_wmb();
q->lock_ptr = NULL;
-
- wake_up_state(p, TASK_NORMAL);
- put_task_struct(p);
}
static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this)
struct futex_q *this, *next;
union futex_key key = FUTEX_KEY_INIT;
int ret;
+ WAKE_Q(wake_q);
if (!bitset)
return -EINVAL;
if (!(this->bitset & bitset))
continue;
- wake_futex(this);
+ mark_wake_futex(&wake_q, this);
if (++ret >= nr_wake)
break;
}
}
spin_unlock(&hb->lock);
+ wake_up_q(&wake_q);
out_put_key:
put_futex_key(&key);
out:
struct futex_hash_bucket *hb1, *hb2;
struct futex_q *this, *next;
int ret, op_ret;
+ WAKE_Q(wake_q);
retry:
ret = get_futex_key(uaddr1, flags & FLAGS_SHARED, &key1, VERIFY_READ);
ret = -EINVAL;
goto out_unlock;
}
- wake_futex(this);
+ mark_wake_futex(&wake_q, this);
if (++ret >= nr_wake)
break;
}
ret = -EINVAL;
goto out_unlock;
}
- wake_futex(this);
+ mark_wake_futex(&wake_q, this);
if (++op_ret >= nr_wake2)
break;
}
out_unlock:
double_unlock_hb(hb1, hb2);
+ wake_up_q(&wake_q);
out_put_keys:
put_futex_key(&key2);
out_put_key1:
struct futex_pi_state *pi_state = NULL;
struct futex_hash_bucket *hb1, *hb2;
struct futex_q *this, *next;
+ WAKE_Q(wake_q);
if (requeue_pi) {
/*
* woken by futex_unlock_pi().
*/
if (++task_count <= nr_wake && !requeue_pi) {
- wake_futex(this);
+ mark_wake_futex(&wake_q, this);
continue;
}
out_unlock:
free_pi_state(pi_state);
double_unlock_hb(hb1, hb2);
+ wake_up_q(&wake_q);
hb_waiters_dec(hb2);
/*
CFLAGS_core.o := $(PROFILING) -fno-omit-frame-pointer
endif
-obj-y += core.o proc.o clock.o cputime.o
+obj-y += core.o loadavg.o clock.o cputime.o
obj-y += idle_task.o fair.o rt.o deadline.o stop_task.o
obj-y += wait.o completion.o idle.o
obj-$(CONFIG_SMP) += cpupri.o cpudeadline.o
-#ifdef CONFIG_SCHED_AUTOGROUP
-
#include "sched.h"
#include <linux/proc_fs.h>
p->signal->autogroup = autogroup_kref_get(ag);
- if (!ACCESS_ONCE(sysctl_sched_autogroup_enabled))
+ if (!READ_ONCE(sysctl_sched_autogroup_enabled))
goto out;
for_each_thread(p, t)
return snprintf(buf, buflen, "%s-%ld", "/autogroup", tg->autogroup->id);
}
#endif /* CONFIG_SCHED_DEBUG */
-
-#endif /* CONFIG_SCHED_AUTOGROUP */
static inline struct task_group *
autogroup_task_group(struct task_struct *p, struct task_group *tg)
{
- int enabled = ACCESS_ONCE(sysctl_sched_autogroup_enabled);
+ int enabled = READ_ONCE(sysctl_sched_autogroup_enabled);
if (enabled && task_wants_autogroup(p, tg))
return p->signal->autogroup->tg;
static bool set_nr_if_polling(struct task_struct *p)
{
struct thread_info *ti = task_thread_info(p);
- typeof(ti->flags) old, val = ACCESS_ONCE(ti->flags);
+ typeof(ti->flags) old, val = READ_ONCE(ti->flags);
for (;;) {
if (!(val & _TIF_POLLING_NRFLAG))
#endif
#endif
+void wake_q_add(struct wake_q_head *head, struct task_struct *task)
+{
+ struct wake_q_node *node = &task->wake_q;
+
+ /*
+ * Atomically grab the task, if ->wake_q is !nil already it means
+ * its already queued (either by us or someone else) and will get the
+ * wakeup due to that.
+ *
+ * This cmpxchg() implies a full barrier, which pairs with the write
+ * barrier implied by the wakeup in wake_up_list().
+ */
+ if (cmpxchg(&node->next, NULL, WAKE_Q_TAIL))
+ return;
+
+ get_task_struct(task);
+
+ /*
+ * The head is context local, there can be no concurrency.
+ */
+ *head->lastp = node;
+ head->lastp = &node->next;
+}
+
+void wake_up_q(struct wake_q_head *head)
+{
+ struct wake_q_node *node = head->first;
+
+ while (node != WAKE_Q_TAIL) {
+ struct task_struct *task;
+
+ task = container_of(node, struct task_struct, wake_q);
+ BUG_ON(!task);
+ /* task can safely be re-inserted now */
+ node = node->next;
+ task->wake_q.next = NULL;
+
+ /*
+ * wake_up_process() implies a wmb() to pair with the queueing
+ * in wake_q_add() so as not to miss wakeups.
+ */
+ wake_up_process(task);
+ put_task_struct(task);
+ }
+}
+
/*
* resched_curr - mark rq's current task 'to be rescheduled now'.
*
void get_iowait_load(unsigned long *nr_waiters, unsigned long *load)
{
- struct rq *this = this_rq();
- *nr_waiters = atomic_read(&this->nr_iowait);
- *load = this->cpu_load[0];
+ struct rq *rq = this_rq();
+ *nr_waiters = atomic_read(&rq->nr_iowait);
+ *load = rq->load.weight;
}
#ifdef CONFIG_SMP
update_rq_clock(rq);
curr->sched_class->task_tick(rq, curr, 0);
update_cpu_load_active(rq);
+ calc_global_load_tick(rq);
raw_spin_unlock(&rq->lock);
perf_event_task_tick();
u64 scheduler_tick_max_deferment(void)
{
struct rq *rq = this_rq();
- unsigned long next, now = ACCESS_ONCE(jiffies);
+ unsigned long next, now = READ_ONCE(jiffies);
next = rq->last_sched_tick + HZ;
* - return from syscall or exception to user-space
* - return from interrupt-handler to user-space
*
- * WARNING: all callers must re-check need_resched() afterward and reschedule
- * accordingly in case an event triggered the need for rescheduling (such as
- * an interrupt waking up a task) while preemption was disabled in __schedule().
+ * WARNING: must be called with preemption disabled!
*/
static void __sched __schedule(void)
{
struct rq *rq;
int cpu;
- preempt_disable();
cpu = smp_processor_id();
rq = cpu_rq(cpu);
rcu_note_context_switch();
raw_spin_unlock_irq(&rq->lock);
post_schedule(rq);
-
- sched_preempt_enable_no_resched();
}
static inline void sched_submit_work(struct task_struct *tsk)
sched_submit_work(tsk);
do {
+ preempt_disable();
__schedule();
+ sched_preempt_enable_no_resched();
} while (need_resched());
}
EXPORT_SYMBOL(schedule);
static void __sched notrace preempt_schedule_common(void)
{
do {
- __preempt_count_add(PREEMPT_ACTIVE);
+ preempt_active_enter();
__schedule();
- __preempt_count_sub(PREEMPT_ACTIVE);
+ preempt_active_exit();
/*
* Check again in case we missed a preemption opportunity
* between schedule and now.
*/
- barrier();
} while (need_resched());
}
return;
do {
- __preempt_count_add(PREEMPT_ACTIVE);
+ preempt_active_enter();
/*
* Needs preempt disabled in case user_exit() is traced
* and the tracer calls preempt_enable_notrace() causing
__schedule();
exception_exit(prev_ctx);
- __preempt_count_sub(PREEMPT_ACTIVE);
- barrier();
+ preempt_active_exit();
} while (need_resched());
}
EXPORT_SYMBOL_GPL(preempt_schedule_context);
prev_state = exception_enter();
do {
- __preempt_count_add(PREEMPT_ACTIVE);
+ preempt_active_enter();
local_irq_enable();
__schedule();
local_irq_disable();
- __preempt_count_sub(PREEMPT_ACTIVE);
-
- /*
- * Check again in case we missed a preemption opportunity
- * between schedule and now.
- */
- barrier();
+ preempt_active_exit();
} while (need_resched());
exception_exit(prev_state);
.priority = CPU_PRI_MIGRATION,
};
-static void __cpuinit set_cpu_rq_start_time(void)
+static void set_cpu_rq_start_time(void)
{
int cpu = smp_processor_id();
struct rq *rq = cpu_rq(cpu);
return rt_runtime_us;
}
-static int sched_group_set_rt_period(struct task_group *tg, long rt_period_us)
+static int sched_group_set_rt_period(struct task_group *tg, u64 rt_period_us)
{
u64 rt_runtime, rt_period;
- rt_period = (u64)rt_period_us * NSEC_PER_USEC;
+ rt_period = rt_period_us * NSEC_PER_USEC;
rt_runtime = tg->rt_bandwidth.rt_runtime;
return tg_set_rt_bandwidth(tg, rt_period, rt_runtime);
{
cputime_t old;
- while (new > (old = ACCESS_ONCE(*counter)))
+ while (new > (old = READ_ONCE(*counter)))
cmpxchg_cputime(counter, old, new);
}
rq = cpu_rq(cpu);
rcu_read_lock();
- curr = ACCESS_ONCE(rq->curr); /* unlocked access */
+ curr = READ_ONCE(rq->curr); /* unlocked access */
/*
* If we are dealing with a -deadline task, we must
*
* This idea comes from the SD scheduler of Con Kolivas:
*/
-static int get_update_sysctl_factor(void)
+static unsigned int get_update_sysctl_factor(void)
{
- unsigned int cpus = min_t(int, num_online_cpus(), 8);
+ unsigned int cpus = min_t(unsigned int, num_online_cpus(), 8);
unsigned int factor;
switch (sysctl_sched_tunable_scaling) {
loff_t *ppos)
{
int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
- int factor = get_update_sysctl_factor();
+ unsigned int factor = get_update_sysctl_factor();
if (ret || !write)
return ret;
static unsigned int task_scan_min(struct task_struct *p)
{
- unsigned int scan_size = ACCESS_ONCE(sysctl_numa_balancing_scan_size);
+ unsigned int scan_size = READ_ONCE(sysctl_numa_balancing_scan_size);
unsigned int scan, floor;
unsigned int windows = 1;
u64 runtime, period;
spinlock_t *group_lock = NULL;
- seq = ACCESS_ONCE(p->mm->numa_scan_seq);
+ /*
+ * The p->mm->numa_scan_seq field gets updated without
+ * exclusive access. Use READ_ONCE() here to ensure
+ * that the field is read in a single access:
+ */
+ seq = READ_ONCE(p->mm->numa_scan_seq);
if (p->numa_scan_seq == seq)
return;
p->numa_scan_seq = seq;
}
rcu_read_lock();
- tsk = ACCESS_ONCE(cpu_rq(cpu)->curr);
+ tsk = READ_ONCE(cpu_rq(cpu)->curr);
if (!cpupid_match_pid(tsk, cpupid))
goto no_join;
static void reset_ptenuma_scan(struct task_struct *p)
{
- ACCESS_ONCE(p->mm->numa_scan_seq)++;
+ /*
+ * We only did a read acquisition of the mmap sem, so
+ * p->mm->numa_scan_seq is written to without exclusive access
+ * and the update is not guaranteed to be atomic. That's not
+ * much of an issue though, since this is just used for
+ * statistical sampling. Use READ_ONCE/WRITE_ONCE, which are not
+ * expensive, to avoid any form of compiler optimizations:
+ */
+ WRITE_ONCE(p->mm->numa_scan_seq, READ_ONCE(p->mm->numa_scan_seq) + 1);
p->mm->numa_scan_offset = 0;
}
}
#ifdef CONFIG_SMP
+
+/*
+ * per rq 'load' arrray crap; XXX kill this.
+ */
+
+/*
+ * The exact cpuload at various idx values, calculated at every tick would be
+ * load = (2^idx - 1) / 2^idx * load + 1 / 2^idx * cur_load
+ *
+ * If a cpu misses updates for n-1 ticks (as it was idle) and update gets called
+ * on nth tick when cpu may be busy, then we have:
+ * load = ((2^idx - 1) / 2^idx)^(n-1) * load
+ * load = (2^idx - 1) / 2^idx) * load + 1 / 2^idx * cur_load
+ *
+ * decay_load_missed() below does efficient calculation of
+ * load = ((2^idx - 1) / 2^idx)^(n-1) * load
+ * avoiding 0..n-1 loop doing load = ((2^idx - 1) / 2^idx) * load
+ *
+ * The calculation is approximated on a 128 point scale.
+ * degrade_zero_ticks is the number of ticks after which load at any
+ * particular idx is approximated to be zero.
+ * degrade_factor is a precomputed table, a row for each load idx.
+ * Each column corresponds to degradation factor for a power of two ticks,
+ * based on 128 point scale.
+ * Example:
+ * row 2, col 3 (=12) says that the degradation at load idx 2 after
+ * 8 ticks is 12/128 (which is an approximation of exact factor 3^8/4^8).
+ *
+ * With this power of 2 load factors, we can degrade the load n times
+ * by looking at 1 bits in n and doing as many mult/shift instead of
+ * n mult/shifts needed by the exact degradation.
+ */
+#define DEGRADE_SHIFT 7
+static const unsigned char
+ degrade_zero_ticks[CPU_LOAD_IDX_MAX] = {0, 8, 32, 64, 128};
+static const unsigned char
+ degrade_factor[CPU_LOAD_IDX_MAX][DEGRADE_SHIFT + 1] = {
+ {0, 0, 0, 0, 0, 0, 0, 0},
+ {64, 32, 8, 0, 0, 0, 0, 0},
+ {96, 72, 40, 12, 1, 0, 0},
+ {112, 98, 75, 43, 15, 1, 0},
+ {120, 112, 98, 76, 45, 16, 2} };
+
+/*
+ * Update cpu_load for any missed ticks, due to tickless idle. The backlog
+ * would be when CPU is idle and so we just decay the old load without
+ * adding any new load.
+ */
+static unsigned long
+decay_load_missed(unsigned long load, unsigned long missed_updates, int idx)
+{
+ int j = 0;
+
+ if (!missed_updates)
+ return load;
+
+ if (missed_updates >= degrade_zero_ticks[idx])
+ return 0;
+
+ if (idx == 1)
+ return load >> missed_updates;
+
+ while (missed_updates) {
+ if (missed_updates % 2)
+ load = (load * degrade_factor[idx][j]) >> DEGRADE_SHIFT;
+
+ missed_updates >>= 1;
+ j++;
+ }
+ return load;
+}
+
+/*
+ * Update rq->cpu_load[] statistics. This function is usually called every
+ * scheduler tick (TICK_NSEC). With tickless idle this will not be called
+ * every tick. We fix it up based on jiffies.
+ */
+static void __update_cpu_load(struct rq *this_rq, unsigned long this_load,
+ unsigned long pending_updates)
+{
+ int i, scale;
+
+ this_rq->nr_load_updates++;
+
+ /* Update our load: */
+ this_rq->cpu_load[0] = this_load; /* Fasttrack for idx 0 */
+ for (i = 1, scale = 2; i < CPU_LOAD_IDX_MAX; i++, scale += scale) {
+ unsigned long old_load, new_load;
+
+ /* scale is effectively 1 << i now, and >> i divides by scale */
+
+ old_load = this_rq->cpu_load[i];
+ old_load = decay_load_missed(old_load, pending_updates - 1, i);
+ new_load = this_load;
+ /*
+ * Round up the averaging division if load is increasing. This
+ * prevents us from getting stuck on 9 if the load is 10, for
+ * example.
+ */
+ if (new_load > old_load)
+ new_load += scale - 1;
+
+ this_rq->cpu_load[i] = (old_load * (scale - 1) + new_load) >> i;
+ }
+
+ sched_avg_update(this_rq);
+}
+
+#ifdef CONFIG_NO_HZ_COMMON
+/*
+ * There is no sane way to deal with nohz on smp when using jiffies because the
+ * cpu doing the jiffies update might drift wrt the cpu doing the jiffy reading
+ * causing off-by-one errors in observed deltas; {0,2} instead of {1,1}.
+ *
+ * Therefore we cannot use the delta approach from the regular tick since that
+ * would seriously skew the load calculation. However we'll make do for those
+ * updates happening while idle (nohz_idle_balance) or coming out of idle
+ * (tick_nohz_idle_exit).
+ *
+ * This means we might still be one tick off for nohz periods.
+ */
+
+/*
+ * Called from nohz_idle_balance() to update the load ratings before doing the
+ * idle balance.
+ */
+static void update_idle_cpu_load(struct rq *this_rq)
+{
+ unsigned long curr_jiffies = READ_ONCE(jiffies);
+ unsigned long load = this_rq->cfs.runnable_load_avg;
+ unsigned long pending_updates;
+
+ /*
+ * bail if there's load or we're actually up-to-date.
+ */
+ if (load || curr_jiffies == this_rq->last_load_update_tick)
+ return;
+
+ pending_updates = curr_jiffies - this_rq->last_load_update_tick;
+ this_rq->last_load_update_tick = curr_jiffies;
+
+ __update_cpu_load(this_rq, load, pending_updates);
+}
+
+/*
+ * Called from tick_nohz_idle_exit() -- try and fix up the ticks we missed.
+ */
+void update_cpu_load_nohz(void)
+{
+ struct rq *this_rq = this_rq();
+ unsigned long curr_jiffies = READ_ONCE(jiffies);
+ unsigned long pending_updates;
+
+ if (curr_jiffies == this_rq->last_load_update_tick)
+ return;
+
+ raw_spin_lock(&this_rq->lock);
+ pending_updates = curr_jiffies - this_rq->last_load_update_tick;
+ if (pending_updates) {
+ this_rq->last_load_update_tick = curr_jiffies;
+ /*
+ * We were idle, this means load 0, the current load might be
+ * !0 due to remote wakeups and the sort.
+ */
+ __update_cpu_load(this_rq, 0, pending_updates);
+ }
+ raw_spin_unlock(&this_rq->lock);
+}
+#endif /* CONFIG_NO_HZ */
+
+/*
+ * Called from scheduler_tick()
+ */
+void update_cpu_load_active(struct rq *this_rq)
+{
+ unsigned long load = this_rq->cfs.runnable_load_avg;
+ /*
+ * See the mess around update_idle_cpu_load() / update_cpu_load_nohz().
+ */
+ this_rq->last_load_update_tick = jiffies;
+ __update_cpu_load(this_rq, load, 1);
+}
+
/* Used instead of source_load when we know the type == 0 */
static unsigned long weighted_cpuload(const int cpu)
{
static unsigned long cpu_avg_load_per_task(int cpu)
{
struct rq *rq = cpu_rq(cpu);
- unsigned long nr_running = ACCESS_ONCE(rq->cfs.h_nr_running);
+ unsigned long nr_running = READ_ONCE(rq->cfs.h_nr_running);
unsigned long load_avg = rq->cfs.runnable_load_avg;
if (nr_running)
}
#ifdef CONFIG_NUMA_BALANCING
-/* Returns true if the destination node has incurred more faults */
+/*
+ * Returns true if the destination node is the preferred node.
+ * Needs to match fbq_classify_rq(): if there is a runnable task
+ * that is not on its preferred node, we should identify it.
+ */
static bool migrate_improves_locality(struct task_struct *p, struct lb_env *env)
{
struct numa_group *numa_group = rcu_dereference(p->numa_group);
+ unsigned long src_faults, dst_faults;
int src_nid, dst_nid;
if (!sched_feat(NUMA_FAVOUR_HIGHER) || !p->numa_faults ||
if (src_nid == dst_nid)
return false;
- if (numa_group) {
- /* Task is already in the group's interleave set. */
- if (node_isset(src_nid, numa_group->active_nodes))
- return false;
-
- /* Task is moving into the group's interleave set. */
- if (node_isset(dst_nid, numa_group->active_nodes))
- return true;
-
- return group_faults(p, dst_nid) > group_faults(p, src_nid);
- }
-
/* Encourage migration to the preferred node. */
if (dst_nid == p->numa_preferred_nid)
return true;
- return task_faults(p, dst_nid) > task_faults(p, src_nid);
+ /* Migrating away from the preferred node is bad. */
+ if (src_nid == p->numa_preferred_nid)
+ return false;
+
+ if (numa_group) {
+ src_faults = group_faults(p, src_nid);
+ dst_faults = group_faults(p, dst_nid);
+ } else {
+ src_faults = task_faults(p, src_nid);
+ dst_faults = task_faults(p, dst_nid);
+ }
+
+ return dst_faults > src_faults;
}
static bool migrate_degrades_locality(struct task_struct *p, struct lb_env *env)
{
struct numa_group *numa_group = rcu_dereference(p->numa_group);
+ unsigned long src_faults, dst_faults;
int src_nid, dst_nid;
if (!sched_feat(NUMA) || !sched_feat(NUMA_RESIST_LOWER))
if (src_nid == dst_nid)
return false;
- if (numa_group) {
- /* Task is moving within/into the group's interleave set. */
- if (node_isset(dst_nid, numa_group->active_nodes))
- return false;
+ /* Migrating away from the preferred node is bad. */
+ if (src_nid == p->numa_preferred_nid)
+ return true;
- /* Task is moving out of the group's interleave set. */
- if (node_isset(src_nid, numa_group->active_nodes))
- return true;
+ /* Encourage migration to the preferred node. */
+ if (dst_nid == p->numa_preferred_nid)
+ return false;
- return group_faults(p, dst_nid) < group_faults(p, src_nid);
+ if (numa_group) {
+ src_faults = group_faults(p, src_nid);
+ dst_faults = group_faults(p, dst_nid);
+ } else {
+ src_faults = task_faults(p, src_nid);
+ dst_faults = task_faults(p, dst_nid);
}
- /* Migrating away from the preferred node is always bad. */
- if (src_nid == p->numa_preferred_nid)
- return true;
-
- return task_faults(p, dst_nid) < task_faults(p, src_nid);
+ return dst_faults < src_faults;
}
#else
* Since we're reading these variables without serialization make sure
* we read them once before doing sanity checks on them.
*/
- age_stamp = ACCESS_ONCE(rq->age_stamp);
- avg = ACCESS_ONCE(rq->rt_avg);
+ age_stamp = READ_ONCE(rq->age_stamp);
+ avg = READ_ONCE(rq->rt_avg);
delta = __rq_clock_broken(rq) - age_stamp;
if (unlikely(delta < 0))
--- /dev/null
+/*
+ * kernel/sched/loadavg.c
+ *
+ * This file contains the magic bits required to compute the global loadavg
+ * figure. Its a silly number but people think its important. We go through
+ * great pains to make it work on big machines and tickless kernels.
+ */
+
+#include <linux/export.h>
+
+#include "sched.h"
+
+/*
+ * Global load-average calculations
+ *
+ * We take a distributed and async approach to calculating the global load-avg
+ * in order to minimize overhead.
+ *
+ * The global load average is an exponentially decaying average of nr_running +
+ * nr_uninterruptible.
+ *
+ * Once every LOAD_FREQ:
+ *
+ * nr_active = 0;
+ * for_each_possible_cpu(cpu)
+ * nr_active += cpu_of(cpu)->nr_running + cpu_of(cpu)->nr_uninterruptible;
+ *
+ * avenrun[n] = avenrun[0] * exp_n + nr_active * (1 - exp_n)
+ *
+ * Due to a number of reasons the above turns in the mess below:
+ *
+ * - for_each_possible_cpu() is prohibitively expensive on machines with
+ * serious number of cpus, therefore we need to take a distributed approach
+ * to calculating nr_active.
+ *
+ * \Sum_i x_i(t) = \Sum_i x_i(t) - x_i(t_0) | x_i(t_0) := 0
+ * = \Sum_i { \Sum_j=1 x_i(t_j) - x_i(t_j-1) }
+ *
+ * So assuming nr_active := 0 when we start out -- true per definition, we
+ * can simply take per-cpu deltas and fold those into a global accumulate
+ * to obtain the same result. See calc_load_fold_active().
+ *
+ * Furthermore, in order to avoid synchronizing all per-cpu delta folding
+ * across the machine, we assume 10 ticks is sufficient time for every
+ * cpu to have completed this task.
+ *
+ * This places an upper-bound on the IRQ-off latency of the machine. Then
+ * again, being late doesn't loose the delta, just wrecks the sample.
+ *
+ * - cpu_rq()->nr_uninterruptible isn't accurately tracked per-cpu because
+ * this would add another cross-cpu cacheline miss and atomic operation
+ * to the wakeup path. Instead we increment on whatever cpu the task ran
+ * when it went into uninterruptible state and decrement on whatever cpu
+ * did the wakeup. This means that only the sum of nr_uninterruptible over
+ * all cpus yields the correct result.
+ *
+ * This covers the NO_HZ=n code, for extra head-aches, see the comment below.
+ */
+
+/* Variables and functions for calc_load */
+atomic_long_t calc_load_tasks;
+unsigned long calc_load_update;
+unsigned long avenrun[3];
+EXPORT_SYMBOL(avenrun); /* should be removed */
+
+/**
+ * get_avenrun - get the load average array
+ * @loads: pointer to dest load array
+ * @offset: offset to add
+ * @shift: shift count to shift the result left
+ *
+ * These values are estimates at best, so no need for locking.
+ */
+void get_avenrun(unsigned long *loads, unsigned long offset, int shift)
+{
+ loads[0] = (avenrun[0] + offset) << shift;
+ loads[1] = (avenrun[1] + offset) << shift;
+ loads[2] = (avenrun[2] + offset) << shift;
+}
+
+long calc_load_fold_active(struct rq *this_rq)
+{
+ long nr_active, delta = 0;
+
+ nr_active = this_rq->nr_running;
+ nr_active += (long)this_rq->nr_uninterruptible;
+
+ if (nr_active != this_rq->calc_load_active) {
+ delta = nr_active - this_rq->calc_load_active;
+ this_rq->calc_load_active = nr_active;
+ }
+
+ return delta;
+}
+
+/*
+ * a1 = a0 * e + a * (1 - e)
+ */
+static unsigned long
+calc_load(unsigned long load, unsigned long exp, unsigned long active)
+{
+ load *= exp;
+ load += active * (FIXED_1 - exp);
+ load += 1UL << (FSHIFT - 1);
+ return load >> FSHIFT;
+}
+
+#ifdef CONFIG_NO_HZ_COMMON
+/*
+ * Handle NO_HZ for the global load-average.
+ *
+ * Since the above described distributed algorithm to compute the global
+ * load-average relies on per-cpu sampling from the tick, it is affected by
+ * NO_HZ.
+ *
+ * The basic idea is to fold the nr_active delta into a global idle-delta upon
+ * entering NO_HZ state such that we can include this as an 'extra' cpu delta
+ * when we read the global state.
+ *
+ * Obviously reality has to ruin such a delightfully simple scheme:
+ *
+ * - When we go NO_HZ idle during the window, we can negate our sample
+ * contribution, causing under-accounting.
+ *
+ * We avoid this by keeping two idle-delta counters and flipping them
+ * when the window starts, thus separating old and new NO_HZ load.
+ *
+ * The only trick is the slight shift in index flip for read vs write.
+ *
+ * 0s 5s 10s 15s
+ * +10 +10 +10 +10
+ * |-|-----------|-|-----------|-|-----------|-|
+ * r:0 0 1 1 0 0 1 1 0
+ * w:0 1 1 0 0 1 1 0 0
+ *
+ * This ensures we'll fold the old idle contribution in this window while
+ * accumlating the new one.
+ *
+ * - When we wake up from NO_HZ idle during the window, we push up our
+ * contribution, since we effectively move our sample point to a known
+ * busy state.
+ *
+ * This is solved by pushing the window forward, and thus skipping the
+ * sample, for this cpu (effectively using the idle-delta for this cpu which
+ * was in effect at the time the window opened). This also solves the issue
+ * of having to deal with a cpu having been in NOHZ idle for multiple
+ * LOAD_FREQ intervals.
+ *
+ * When making the ILB scale, we should try to pull this in as well.
+ */
+static atomic_long_t calc_load_idle[2];
+static int calc_load_idx;
+
+static inline int calc_load_write_idx(void)
+{
+ int idx = calc_load_idx;
+
+ /*
+ * See calc_global_nohz(), if we observe the new index, we also
+ * need to observe the new update time.
+ */
+ smp_rmb();
+
+ /*
+ * If the folding window started, make sure we start writing in the
+ * next idle-delta.
+ */
+ if (!time_before(jiffies, calc_load_update))
+ idx++;
+
+ return idx & 1;
+}
+
+static inline int calc_load_read_idx(void)
+{
+ return calc_load_idx & 1;
+}
+
+void calc_load_enter_idle(void)
+{
+ struct rq *this_rq = this_rq();
+ long delta;
+
+ /*
+ * We're going into NOHZ mode, if there's any pending delta, fold it
+ * into the pending idle delta.
+ */
+ delta = calc_load_fold_active(this_rq);
+ if (delta) {
+ int idx = calc_load_write_idx();
+
+ atomic_long_add(delta, &calc_load_idle[idx]);
+ }
+}
+
+void calc_load_exit_idle(void)
+{
+ struct rq *this_rq = this_rq();
+
+ /*
+ * If we're still before the sample window, we're done.
+ */
+ if (time_before(jiffies, this_rq->calc_load_update))
+ return;
+
+ /*
+ * We woke inside or after the sample window, this means we're already
+ * accounted through the nohz accounting, so skip the entire deal and
+ * sync up for the next window.
+ */
+ this_rq->calc_load_update = calc_load_update;
+ if (time_before(jiffies, this_rq->calc_load_update + 10))
+ this_rq->calc_load_update += LOAD_FREQ;
+}
+
+static long calc_load_fold_idle(void)
+{
+ int idx = calc_load_read_idx();
+ long delta = 0;
+
+ if (atomic_long_read(&calc_load_idle[idx]))
+ delta = atomic_long_xchg(&calc_load_idle[idx], 0);
+
+ return delta;
+}
+
+/**
+ * fixed_power_int - compute: x^n, in O(log n) time
+ *
+ * @x: base of the power
+ * @frac_bits: fractional bits of @x
+ * @n: power to raise @x to.
+ *
+ * By exploiting the relation between the definition of the natural power
+ * function: x^n := x*x*...*x (x multiplied by itself for n times), and
+ * the binary encoding of numbers used by computers: n := \Sum n_i * 2^i,
+ * (where: n_i \elem {0, 1}, the binary vector representing n),
+ * we find: x^n := x^(\Sum n_i * 2^i) := \Prod x^(n_i * 2^i), which is
+ * of course trivially computable in O(log_2 n), the length of our binary
+ * vector.
+ */
+static unsigned long
+fixed_power_int(unsigned long x, unsigned int frac_bits, unsigned int n)
+{
+ unsigned long result = 1UL << frac_bits;
+
+ if (n) {
+ for (;;) {
+ if (n & 1) {
+ result *= x;
+ result += 1UL << (frac_bits - 1);
+ result >>= frac_bits;
+ }
+ n >>= 1;
+ if (!n)
+ break;
+ x *= x;
+ x += 1UL << (frac_bits - 1);
+ x >>= frac_bits;
+ }
+ }
+
+ return result;
+}
+
+/*
+ * a1 = a0 * e + a * (1 - e)
+ *
+ * a2 = a1 * e + a * (1 - e)
+ * = (a0 * e + a * (1 - e)) * e + a * (1 - e)
+ * = a0 * e^2 + a * (1 - e) * (1 + e)
+ *
+ * a3 = a2 * e + a * (1 - e)
+ * = (a0 * e^2 + a * (1 - e) * (1 + e)) * e + a * (1 - e)
+ * = a0 * e^3 + a * (1 - e) * (1 + e + e^2)
+ *
+ * ...
+ *
+ * an = a0 * e^n + a * (1 - e) * (1 + e + ... + e^n-1) [1]
+ * = a0 * e^n + a * (1 - e) * (1 - e^n)/(1 - e)
+ * = a0 * e^n + a * (1 - e^n)
+ *
+ * [1] application of the geometric series:
+ *
+ * n 1 - x^(n+1)
+ * S_n := \Sum x^i = -------------
+ * i=0 1 - x
+ */
+static unsigned long
+calc_load_n(unsigned long load, unsigned long exp,
+ unsigned long active, unsigned int n)
+{
+ return calc_load(load, fixed_power_int(exp, FSHIFT, n), active);
+}
+
+/*
+ * NO_HZ can leave us missing all per-cpu ticks calling
+ * calc_load_account_active(), but since an idle CPU folds its delta into
+ * calc_load_tasks_idle per calc_load_account_idle(), all we need to do is fold
+ * in the pending idle delta if our idle period crossed a load cycle boundary.
+ *
+ * Once we've updated the global active value, we need to apply the exponential
+ * weights adjusted to the number of cycles missed.
+ */
+static void calc_global_nohz(void)
+{
+ long delta, active, n;
+
+ if (!time_before(jiffies, calc_load_update + 10)) {
+ /*
+ * Catch-up, fold however many we are behind still
+ */
+ delta = jiffies - calc_load_update - 10;
+ n = 1 + (delta / LOAD_FREQ);
+
+ active = atomic_long_read(&calc_load_tasks);
+ active = active > 0 ? active * FIXED_1 : 0;
+
+ avenrun[0] = calc_load_n(avenrun[0], EXP_1, active, n);
+ avenrun[1] = calc_load_n(avenrun[1], EXP_5, active, n);
+ avenrun[2] = calc_load_n(avenrun[2], EXP_15, active, n);
+
+ calc_load_update += n * LOAD_FREQ;
+ }
+
+ /*
+ * Flip the idle index...
+ *
+ * Make sure we first write the new time then flip the index, so that
+ * calc_load_write_idx() will see the new time when it reads the new
+ * index, this avoids a double flip messing things up.
+ */
+ smp_wmb();
+ calc_load_idx++;
+}
+#else /* !CONFIG_NO_HZ_COMMON */
+
+static inline long calc_load_fold_idle(void) { return 0; }
+static inline void calc_global_nohz(void) { }
+
+#endif /* CONFIG_NO_HZ_COMMON */
+
+/*
+ * calc_load - update the avenrun load estimates 10 ticks after the
+ * CPUs have updated calc_load_tasks.
+ *
+ * Called from the global timer code.
+ */
+void calc_global_load(unsigned long ticks)
+{
+ long active, delta;
+
+ if (time_before(jiffies, calc_load_update + 10))
+ return;
+
+ /*
+ * Fold the 'old' idle-delta to include all NO_HZ cpus.
+ */
+ delta = calc_load_fold_idle();
+ if (delta)
+ atomic_long_add(delta, &calc_load_tasks);
+
+ active = atomic_long_read(&calc_load_tasks);
+ active = active > 0 ? active * FIXED_1 : 0;
+
+ avenrun[0] = calc_load(avenrun[0], EXP_1, active);
+ avenrun[1] = calc_load(avenrun[1], EXP_5, active);
+ avenrun[2] = calc_load(avenrun[2], EXP_15, active);
+
+ calc_load_update += LOAD_FREQ;
+
+ /*
+ * In case we idled for multiple LOAD_FREQ intervals, catch up in bulk.
+ */
+ calc_global_nohz();
+}
+
+/*
+ * Called from scheduler_tick() to periodically update this CPU's
+ * active count.
+ */
+void calc_global_load_tick(struct rq *this_rq)
+{
+ long delta;
+
+ if (time_before(jiffies, this_rq->calc_load_update))
+ return;
+
+ delta = calc_load_fold_active(this_rq);
+ if (delta)
+ atomic_long_add(delta, &calc_load_tasks);
+
+ this_rq->calc_load_update += LOAD_FREQ;
+}
+++ /dev/null
-/*
- * kernel/sched/proc.c
- *
- * Kernel load calculations, forked from sched/core.c
- */
-
-#include <linux/export.h>
-
-#include "sched.h"
-
-/*
- * Global load-average calculations
- *
- * We take a distributed and async approach to calculating the global load-avg
- * in order to minimize overhead.
- *
- * The global load average is an exponentially decaying average of nr_running +
- * nr_uninterruptible.
- *
- * Once every LOAD_FREQ:
- *
- * nr_active = 0;
- * for_each_possible_cpu(cpu)
- * nr_active += cpu_of(cpu)->nr_running + cpu_of(cpu)->nr_uninterruptible;
- *
- * avenrun[n] = avenrun[0] * exp_n + nr_active * (1 - exp_n)
- *
- * Due to a number of reasons the above turns in the mess below:
- *
- * - for_each_possible_cpu() is prohibitively expensive on machines with
- * serious number of cpus, therefore we need to take a distributed approach
- * to calculating nr_active.
- *
- * \Sum_i x_i(t) = \Sum_i x_i(t) - x_i(t_0) | x_i(t_0) := 0
- * = \Sum_i { \Sum_j=1 x_i(t_j) - x_i(t_j-1) }
- *
- * So assuming nr_active := 0 when we start out -- true per definition, we
- * can simply take per-cpu deltas and fold those into a global accumulate
- * to obtain the same result. See calc_load_fold_active().
- *
- * Furthermore, in order to avoid synchronizing all per-cpu delta folding
- * across the machine, we assume 10 ticks is sufficient time for every
- * cpu to have completed this task.
- *
- * This places an upper-bound on the IRQ-off latency of the machine. Then
- * again, being late doesn't loose the delta, just wrecks the sample.
- *
- * - cpu_rq()->nr_uninterruptible isn't accurately tracked per-cpu because
- * this would add another cross-cpu cacheline miss and atomic operation
- * to the wakeup path. Instead we increment on whatever cpu the task ran
- * when it went into uninterruptible state and decrement on whatever cpu
- * did the wakeup. This means that only the sum of nr_uninterruptible over
- * all cpus yields the correct result.
- *
- * This covers the NO_HZ=n code, for extra head-aches, see the comment below.
- */
-
-/* Variables and functions for calc_load */
-atomic_long_t calc_load_tasks;
-unsigned long calc_load_update;
-unsigned long avenrun[3];
-EXPORT_SYMBOL(avenrun); /* should be removed */
-
-/**
- * get_avenrun - get the load average array
- * @loads: pointer to dest load array
- * @offset: offset to add
- * @shift: shift count to shift the result left
- *
- * These values are estimates at best, so no need for locking.
- */
-void get_avenrun(unsigned long *loads, unsigned long offset, int shift)
-{
- loads[0] = (avenrun[0] + offset) << shift;
- loads[1] = (avenrun[1] + offset) << shift;
- loads[2] = (avenrun[2] + offset) << shift;
-}
-
-long calc_load_fold_active(struct rq *this_rq)
-{
- long nr_active, delta = 0;
-
- nr_active = this_rq->nr_running;
- nr_active += (long) this_rq->nr_uninterruptible;
-
- if (nr_active != this_rq->calc_load_active) {
- delta = nr_active - this_rq->calc_load_active;
- this_rq->calc_load_active = nr_active;
- }
-
- return delta;
-}
-
-/*
- * a1 = a0 * e + a * (1 - e)
- */
-static unsigned long
-calc_load(unsigned long load, unsigned long exp, unsigned long active)
-{
- load *= exp;
- load += active * (FIXED_1 - exp);
- load += 1UL << (FSHIFT - 1);
- return load >> FSHIFT;
-}
-
-#ifdef CONFIG_NO_HZ_COMMON
-/*
- * Handle NO_HZ for the global load-average.
- *
- * Since the above described distributed algorithm to compute the global
- * load-average relies on per-cpu sampling from the tick, it is affected by
- * NO_HZ.
- *
- * The basic idea is to fold the nr_active delta into a global idle-delta upon
- * entering NO_HZ state such that we can include this as an 'extra' cpu delta
- * when we read the global state.
- *
- * Obviously reality has to ruin such a delightfully simple scheme:
- *
- * - When we go NO_HZ idle during the window, we can negate our sample
- * contribution, causing under-accounting.
- *
- * We avoid this by keeping two idle-delta counters and flipping them
- * when the window starts, thus separating old and new NO_HZ load.
- *
- * The only trick is the slight shift in index flip for read vs write.
- *
- * 0s 5s 10s 15s
- * +10 +10 +10 +10
- * |-|-----------|-|-----------|-|-----------|-|
- * r:0 0 1 1 0 0 1 1 0
- * w:0 1 1 0 0 1 1 0 0
- *
- * This ensures we'll fold the old idle contribution in this window while
- * accumlating the new one.
- *
- * - When we wake up from NO_HZ idle during the window, we push up our
- * contribution, since we effectively move our sample point to a known
- * busy state.
- *
- * This is solved by pushing the window forward, and thus skipping the
- * sample, for this cpu (effectively using the idle-delta for this cpu which
- * was in effect at the time the window opened). This also solves the issue
- * of having to deal with a cpu having been in NOHZ idle for multiple
- * LOAD_FREQ intervals.
- *
- * When making the ILB scale, we should try to pull this in as well.
- */
-static atomic_long_t calc_load_idle[2];
-static int calc_load_idx;
-
-static inline int calc_load_write_idx(void)
-{
- int idx = calc_load_idx;
-
- /*
- * See calc_global_nohz(), if we observe the new index, we also
- * need to observe the new update time.
- */
- smp_rmb();
-
- /*
- * If the folding window started, make sure we start writing in the
- * next idle-delta.
- */
- if (!time_before(jiffies, calc_load_update))
- idx++;
-
- return idx & 1;
-}
-
-static inline int calc_load_read_idx(void)
-{
- return calc_load_idx & 1;
-}
-
-void calc_load_enter_idle(void)
-{
- struct rq *this_rq = this_rq();
- long delta;
-
- /*
- * We're going into NOHZ mode, if there's any pending delta, fold it
- * into the pending idle delta.
- */
- delta = calc_load_fold_active(this_rq);
- if (delta) {
- int idx = calc_load_write_idx();
- atomic_long_add(delta, &calc_load_idle[idx]);
- }
-}
-
-void calc_load_exit_idle(void)
-{
- struct rq *this_rq = this_rq();
-
- /*
- * If we're still before the sample window, we're done.
- */
- if (time_before(jiffies, this_rq->calc_load_update))
- return;
-
- /*
- * We woke inside or after the sample window, this means we're already
- * accounted through the nohz accounting, so skip the entire deal and
- * sync up for the next window.
- */
- this_rq->calc_load_update = calc_load_update;
- if (time_before(jiffies, this_rq->calc_load_update + 10))
- this_rq->calc_load_update += LOAD_FREQ;
-}
-
-static long calc_load_fold_idle(void)
-{
- int idx = calc_load_read_idx();
- long delta = 0;
-
- if (atomic_long_read(&calc_load_idle[idx]))
- delta = atomic_long_xchg(&calc_load_idle[idx], 0);
-
- return delta;
-}
-
-/**
- * fixed_power_int - compute: x^n, in O(log n) time
- *
- * @x: base of the power
- * @frac_bits: fractional bits of @x
- * @n: power to raise @x to.
- *
- * By exploiting the relation between the definition of the natural power
- * function: x^n := x*x*...*x (x multiplied by itself for n times), and
- * the binary encoding of numbers used by computers: n := \Sum n_i * 2^i,
- * (where: n_i \elem {0, 1}, the binary vector representing n),
- * we find: x^n := x^(\Sum n_i * 2^i) := \Prod x^(n_i * 2^i), which is
- * of course trivially computable in O(log_2 n), the length of our binary
- * vector.
- */
-static unsigned long
-fixed_power_int(unsigned long x, unsigned int frac_bits, unsigned int n)
-{
- unsigned long result = 1UL << frac_bits;
-
- if (n) for (;;) {
- if (n & 1) {
- result *= x;
- result += 1UL << (frac_bits - 1);
- result >>= frac_bits;
- }
- n >>= 1;
- if (!n)
- break;
- x *= x;
- x += 1UL << (frac_bits - 1);
- x >>= frac_bits;
- }
-
- return result;
-}
-
-/*
- * a1 = a0 * e + a * (1 - e)
- *
- * a2 = a1 * e + a * (1 - e)
- * = (a0 * e + a * (1 - e)) * e + a * (1 - e)
- * = a0 * e^2 + a * (1 - e) * (1 + e)
- *
- * a3 = a2 * e + a * (1 - e)
- * = (a0 * e^2 + a * (1 - e) * (1 + e)) * e + a * (1 - e)
- * = a0 * e^3 + a * (1 - e) * (1 + e + e^2)
- *
- * ...
- *
- * an = a0 * e^n + a * (1 - e) * (1 + e + ... + e^n-1) [1]
- * = a0 * e^n + a * (1 - e) * (1 - e^n)/(1 - e)
- * = a0 * e^n + a * (1 - e^n)
- *
- * [1] application of the geometric series:
- *
- * n 1 - x^(n+1)
- * S_n := \Sum x^i = -------------
- * i=0 1 - x
- */
-static unsigned long
-calc_load_n(unsigned long load, unsigned long exp,
- unsigned long active, unsigned int n)
-{
-
- return calc_load(load, fixed_power_int(exp, FSHIFT, n), active);
-}
-
-/*
- * NO_HZ can leave us missing all per-cpu ticks calling
- * calc_load_account_active(), but since an idle CPU folds its delta into
- * calc_load_tasks_idle per calc_load_account_idle(), all we need to do is fold
- * in the pending idle delta if our idle period crossed a load cycle boundary.
- *
- * Once we've updated the global active value, we need to apply the exponential
- * weights adjusted to the number of cycles missed.
- */
-static void calc_global_nohz(void)
-{
- long delta, active, n;
-
- if (!time_before(jiffies, calc_load_update + 10)) {
- /*
- * Catch-up, fold however many we are behind still
- */
- delta = jiffies - calc_load_update - 10;
- n = 1 + (delta / LOAD_FREQ);
-
- active = atomic_long_read(&calc_load_tasks);
- active = active > 0 ? active * FIXED_1 : 0;
-
- avenrun[0] = calc_load_n(avenrun[0], EXP_1, active, n);
- avenrun[1] = calc_load_n(avenrun[1], EXP_5, active, n);
- avenrun[2] = calc_load_n(avenrun[2], EXP_15, active, n);
-
- calc_load_update += n * LOAD_FREQ;
- }
-
- /*
- * Flip the idle index...
- *
- * Make sure we first write the new time then flip the index, so that
- * calc_load_write_idx() will see the new time when it reads the new
- * index, this avoids a double flip messing things up.
- */
- smp_wmb();
- calc_load_idx++;
-}
-#else /* !CONFIG_NO_HZ_COMMON */
-
-static inline long calc_load_fold_idle(void) { return 0; }
-static inline void calc_global_nohz(void) { }
-
-#endif /* CONFIG_NO_HZ_COMMON */
-
-/*
- * calc_load - update the avenrun load estimates 10 ticks after the
- * CPUs have updated calc_load_tasks.
- */
-void calc_global_load(unsigned long ticks)
-{
- long active, delta;
-
- if (time_before(jiffies, calc_load_update + 10))
- return;
-
- /*
- * Fold the 'old' idle-delta to include all NO_HZ cpus.
- */
- delta = calc_load_fold_idle();
- if (delta)
- atomic_long_add(delta, &calc_load_tasks);
-
- active = atomic_long_read(&calc_load_tasks);
- active = active > 0 ? active * FIXED_1 : 0;
-
- avenrun[0] = calc_load(avenrun[0], EXP_1, active);
- avenrun[1] = calc_load(avenrun[1], EXP_5, active);
- avenrun[2] = calc_load(avenrun[2], EXP_15, active);
-
- calc_load_update += LOAD_FREQ;
-
- /*
- * In case we idled for multiple LOAD_FREQ intervals, catch up in bulk.
- */
- calc_global_nohz();
-}
-
-/*
- * Called from update_cpu_load() to periodically update this CPU's
- * active count.
- */
-static void calc_load_account_active(struct rq *this_rq)
-{
- long delta;
-
- if (time_before(jiffies, this_rq->calc_load_update))
- return;
-
- delta = calc_load_fold_active(this_rq);
- if (delta)
- atomic_long_add(delta, &calc_load_tasks);
-
- this_rq->calc_load_update += LOAD_FREQ;
-}
-
-/*
- * End of global load-average stuff
- */
-
-/*
- * The exact cpuload at various idx values, calculated at every tick would be
- * load = (2^idx - 1) / 2^idx * load + 1 / 2^idx * cur_load
- *
- * If a cpu misses updates for n-1 ticks (as it was idle) and update gets called
- * on nth tick when cpu may be busy, then we have:
- * load = ((2^idx - 1) / 2^idx)^(n-1) * load
- * load = (2^idx - 1) / 2^idx) * load + 1 / 2^idx * cur_load
- *
- * decay_load_missed() below does efficient calculation of
- * load = ((2^idx - 1) / 2^idx)^(n-1) * load
- * avoiding 0..n-1 loop doing load = ((2^idx - 1) / 2^idx) * load
- *
- * The calculation is approximated on a 128 point scale.
- * degrade_zero_ticks is the number of ticks after which load at any
- * particular idx is approximated to be zero.
- * degrade_factor is a precomputed table, a row for each load idx.
- * Each column corresponds to degradation factor for a power of two ticks,
- * based on 128 point scale.
- * Example:
- * row 2, col 3 (=12) says that the degradation at load idx 2 after
- * 8 ticks is 12/128 (which is an approximation of exact factor 3^8/4^8).
- *
- * With this power of 2 load factors, we can degrade the load n times
- * by looking at 1 bits in n and doing as many mult/shift instead of
- * n mult/shifts needed by the exact degradation.
- */
-#define DEGRADE_SHIFT 7
-static const unsigned char
- degrade_zero_ticks[CPU_LOAD_IDX_MAX] = {0, 8, 32, 64, 128};
-static const unsigned char
- degrade_factor[CPU_LOAD_IDX_MAX][DEGRADE_SHIFT + 1] = {
- {0, 0, 0, 0, 0, 0, 0, 0},
- {64, 32, 8, 0, 0, 0, 0, 0},
- {96, 72, 40, 12, 1, 0, 0},
- {112, 98, 75, 43, 15, 1, 0},
- {120, 112, 98, 76, 45, 16, 2} };
-
-/*
- * Update cpu_load for any missed ticks, due to tickless idle. The backlog
- * would be when CPU is idle and so we just decay the old load without
- * adding any new load.
- */
-static unsigned long
-decay_load_missed(unsigned long load, unsigned long missed_updates, int idx)
-{
- int j = 0;
-
- if (!missed_updates)
- return load;
-
- if (missed_updates >= degrade_zero_ticks[idx])
- return 0;
-
- if (idx == 1)
- return load >> missed_updates;
-
- while (missed_updates) {
- if (missed_updates % 2)
- load = (load * degrade_factor[idx][j]) >> DEGRADE_SHIFT;
-
- missed_updates >>= 1;
- j++;
- }
- return load;
-}
-
-/*
- * Update rq->cpu_load[] statistics. This function is usually called every
- * scheduler tick (TICK_NSEC). With tickless idle this will not be called
- * every tick. We fix it up based on jiffies.
- */
-static void __update_cpu_load(struct rq *this_rq, unsigned long this_load,
- unsigned long pending_updates)
-{
- int i, scale;
-
- this_rq->nr_load_updates++;
-
- /* Update our load: */
- this_rq->cpu_load[0] = this_load; /* Fasttrack for idx 0 */
- for (i = 1, scale = 2; i < CPU_LOAD_IDX_MAX; i++, scale += scale) {
- unsigned long old_load, new_load;
-
- /* scale is effectively 1 << i now, and >> i divides by scale */
-
- old_load = this_rq->cpu_load[i];
- old_load = decay_load_missed(old_load, pending_updates - 1, i);
- new_load = this_load;
- /*
- * Round up the averaging division if load is increasing. This
- * prevents us from getting stuck on 9 if the load is 10, for
- * example.
- */
- if (new_load > old_load)
- new_load += scale - 1;
-
- this_rq->cpu_load[i] = (old_load * (scale - 1) + new_load) >> i;
- }
-
- sched_avg_update(this_rq);
-}
-
-#ifdef CONFIG_SMP
-static inline unsigned long get_rq_runnable_load(struct rq *rq)
-{
- return rq->cfs.runnable_load_avg;
-}
-#else
-static inline unsigned long get_rq_runnable_load(struct rq *rq)
-{
- return rq->load.weight;
-}
-#endif
-
-#ifdef CONFIG_NO_HZ_COMMON
-/*
- * There is no sane way to deal with nohz on smp when using jiffies because the
- * cpu doing the jiffies update might drift wrt the cpu doing the jiffy reading
- * causing off-by-one errors in observed deltas; {0,2} instead of {1,1}.
- *
- * Therefore we cannot use the delta approach from the regular tick since that
- * would seriously skew the load calculation. However we'll make do for those
- * updates happening while idle (nohz_idle_balance) or coming out of idle
- * (tick_nohz_idle_exit).
- *
- * This means we might still be one tick off for nohz periods.
- */
-
-/*
- * Called from nohz_idle_balance() to update the load ratings before doing the
- * idle balance.
- */
-void update_idle_cpu_load(struct rq *this_rq)
-{
- unsigned long curr_jiffies = ACCESS_ONCE(jiffies);
- unsigned long load = get_rq_runnable_load(this_rq);
- unsigned long pending_updates;
-
- /*
- * bail if there's load or we're actually up-to-date.
- */
- if (load || curr_jiffies == this_rq->last_load_update_tick)
- return;
-
- pending_updates = curr_jiffies - this_rq->last_load_update_tick;
- this_rq->last_load_update_tick = curr_jiffies;
-
- __update_cpu_load(this_rq, load, pending_updates);
-}
-
-/*
- * Called from tick_nohz_idle_exit() -- try and fix up the ticks we missed.
- */
-void update_cpu_load_nohz(void)
-{
- struct rq *this_rq = this_rq();
- unsigned long curr_jiffies = ACCESS_ONCE(jiffies);
- unsigned long pending_updates;
-
- if (curr_jiffies == this_rq->last_load_update_tick)
- return;
-
- raw_spin_lock(&this_rq->lock);
- pending_updates = curr_jiffies - this_rq->last_load_update_tick;
- if (pending_updates) {
- this_rq->last_load_update_tick = curr_jiffies;
- /*
- * We were idle, this means load 0, the current load might be
- * !0 due to remote wakeups and the sort.
- */
- __update_cpu_load(this_rq, 0, pending_updates);
- }
- raw_spin_unlock(&this_rq->lock);
-}
-#endif /* CONFIG_NO_HZ */
-
-/*
- * Called from scheduler_tick()
- */
-void update_cpu_load_active(struct rq *this_rq)
-{
- unsigned long load = get_rq_runnable_load(this_rq);
- /*
- * See the mess around update_idle_cpu_load() / update_cpu_load_nohz().
- */
- this_rq->last_load_update_tick = jiffies;
- __update_cpu_load(this_rq, load, 1);
-
- calc_load_account_active(this_rq);
-}
rq = cpu_rq(cpu);
rcu_read_lock();
- curr = ACCESS_ONCE(rq->curr); /* unlocked access */
+ curr = READ_ONCE(rq->curr); /* unlocked access */
/*
* If the current task on @p's runqueue is an RT task, then
extern unsigned long calc_load_update;
extern atomic_long_t calc_load_tasks;
+extern void calc_global_load_tick(struct rq *this_rq);
extern long calc_load_fold_active(struct rq *this_rq);
+
+#ifdef CONFIG_SMP
extern void update_cpu_load_active(struct rq *this_rq);
+#else
+static inline void update_cpu_load_active(struct rq *this_rq) { }
+#endif
/*
* Helpers for converting nanosecond timing to jiffy resolution
static inline u64 __rq_clock_broken(struct rq *rq)
{
- return ACCESS_ONCE(rq->clock);
+ return READ_ONCE(rq->clock);
}
static inline u64 rq_clock(struct rq *rq)
unsigned long to_ratio(u64 period, u64 runtime);
-extern void update_idle_cpu_load(struct rq *this_rq);
-
extern void init_task_runnable_average(struct task_struct *p);
static inline void add_nr_running(struct rq *rq, unsigned count)
{
struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
- if (!cputimer->running)
+ /* Check if cputimer isn't running. This is accessed without locking. */
+ if (!READ_ONCE(cputimer->running))
return false;
/*
if (!cputimer_running(tsk))
return;
- raw_spin_lock(&cputimer->lock);
- cputimer->cputime.utime += cputime;
- raw_spin_unlock(&cputimer->lock);
+ atomic64_add(cputime, &cputimer->cputime_atomic.utime);
}
/**
if (!cputimer_running(tsk))
return;
- raw_spin_lock(&cputimer->lock);
- cputimer->cputime.stime += cputime;
- raw_spin_unlock(&cputimer->lock);
+ atomic64_add(cputime, &cputimer->cputime_atomic.stime);
}
/**
if (!cputimer_running(tsk))
return;
- raw_spin_lock(&cputimer->lock);
- cputimer->cputime.sum_exec_runtime += ns;
- raw_spin_unlock(&cputimer->lock);
+ atomic64_add(ns, &cputimer->cputime_atomic.sum_exec_runtime);
}
__sched int bit_wait_timeout(struct wait_bit_key *word)
{
- unsigned long now = ACCESS_ONCE(jiffies);
+ unsigned long now = READ_ONCE(jiffies);
if (signal_pending_state(current->state, current))
return 1;
if (time_after_eq(now, word->timeout))
__sched int bit_wait_io_timeout(struct wait_bit_key *word)
{
- unsigned long now = ACCESS_ONCE(jiffies);
+ unsigned long now = READ_ONCE(jiffies);
if (signal_pending_state(current->state, current))
return 1;
if (time_after_eq(now, word->timeout))
* RETURNS:
* %true if @mask is set, %false if made noop because @task was dying.
*/
-bool task_set_jobctl_pending(struct task_struct *task, unsigned int mask)
+bool task_set_jobctl_pending(struct task_struct *task, unsigned long mask)
{
BUG_ON(mask & ~(JOBCTL_PENDING_MASK | JOBCTL_STOP_CONSUME |
JOBCTL_STOP_SIGMASK | JOBCTL_TRAPPING));
* CONTEXT:
* Must be called with @task->sighand->siglock held.
*/
-void task_clear_jobctl_pending(struct task_struct *task, unsigned int mask)
+void task_clear_jobctl_pending(struct task_struct *task, unsigned long mask)
{
BUG_ON(mask & ~JOBCTL_PENDING_MASK);
struct signal_struct *sig = current->signal;
if (!(current->jobctl & JOBCTL_STOP_PENDING)) {
- unsigned int gstop = JOBCTL_STOP_PENDING | JOBCTL_STOP_CONSUME;
+ unsigned long gstop = JOBCTL_STOP_PENDING | JOBCTL_STOP_CONSUME;
struct task_struct *t;
/* signr will be recorded in task->jobctl for retries */
return 0;
}
-static void update_gt_cputime(struct task_cputime *a, struct task_cputime *b)
+/*
+ * Set cputime to sum_cputime if sum_cputime > cputime. Use cmpxchg
+ * to avoid race conditions with concurrent updates to cputime.
+ */
+static inline void __update_gt_cputime(atomic64_t *cputime, u64 sum_cputime)
{
- if (b->utime > a->utime)
- a->utime = b->utime;
+ u64 curr_cputime;
+retry:
+ curr_cputime = atomic64_read(cputime);
+ if (sum_cputime > curr_cputime) {
+ if (atomic64_cmpxchg(cputime, curr_cputime, sum_cputime) != curr_cputime)
+ goto retry;
+ }
+}
- if (b->stime > a->stime)
- a->stime = b->stime;
+static void update_gt_cputime(struct task_cputime_atomic *cputime_atomic, struct task_cputime *sum)
+{
+ __update_gt_cputime(&cputime_atomic->utime, sum->utime);
+ __update_gt_cputime(&cputime_atomic->stime, sum->stime);
+ __update_gt_cputime(&cputime_atomic->sum_exec_runtime, sum->sum_exec_runtime);
+}
- if (b->sum_exec_runtime > a->sum_exec_runtime)
- a->sum_exec_runtime = b->sum_exec_runtime;
+/* Sample task_cputime_atomic values in "atomic_timers", store results in "times". */
+static inline void sample_cputime_atomic(struct task_cputime *times,
+ struct task_cputime_atomic *atomic_times)
+{
+ times->utime = atomic64_read(&atomic_times->utime);
+ times->stime = atomic64_read(&atomic_times->stime);
+ times->sum_exec_runtime = atomic64_read(&atomic_times->sum_exec_runtime);
}
void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times)
{
struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
struct task_cputime sum;
- unsigned long flags;
- if (!cputimer->running) {
+ /* Check if cputimer isn't running. This is accessed without locking. */
+ if (!READ_ONCE(cputimer->running)) {
/*
* The POSIX timer interface allows for absolute time expiry
* values through the TIMER_ABSTIME flag, therefore we have
- * to synchronize the timer to the clock every time we start
- * it.
+ * to synchronize the timer to the clock every time we start it.
*/
thread_group_cputime(tsk, &sum);
- raw_spin_lock_irqsave(&cputimer->lock, flags);
- cputimer->running = 1;
- update_gt_cputime(&cputimer->cputime, &sum);
- } else
- raw_spin_lock_irqsave(&cputimer->lock, flags);
- *times = cputimer->cputime;
- raw_spin_unlock_irqrestore(&cputimer->lock, flags);
+ update_gt_cputime(&cputimer->cputime_atomic, &sum);
+
+ /*
+ * We're setting cputimer->running without a lock. Ensure
+ * this only gets written to in one operation. We set
+ * running after update_gt_cputime() as a small optimization,
+ * but barriers are not required because update_gt_cputime()
+ * can handle concurrent updates.
+ */
+ WRITE_ONCE(cputimer->running, 1);
+ }
+ sample_cputime_atomic(times, &cputimer->cputime_atomic);
}
/*
if (!task_cputime_zero(&tsk->cputime_expires))
return false;
- if (tsk->signal->cputimer.running)
+ /* Check if cputimer is running. This is accessed without locking. */
+ if (READ_ONCE(tsk->signal->cputimer.running))
return false;
return true;
/*
* Check for the special case thread timers.
*/
- soft = ACCESS_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_cur);
+ soft = READ_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_cur);
if (soft != RLIM_INFINITY) {
unsigned long hard =
- ACCESS_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_max);
+ READ_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_max);
if (hard != RLIM_INFINITY &&
tsk->rt.timeout > DIV_ROUND_UP(hard, USEC_PER_SEC/HZ)) {
}
}
-static void stop_process_timers(struct signal_struct *sig)
+static inline void stop_process_timers(struct signal_struct *sig)
{
struct thread_group_cputimer *cputimer = &sig->cputimer;
- unsigned long flags;
- raw_spin_lock_irqsave(&cputimer->lock, flags);
- cputimer->running = 0;
- raw_spin_unlock_irqrestore(&cputimer->lock, flags);
+ /* Turn off cputimer->running. This is done without locking. */
+ WRITE_ONCE(cputimer->running, 0);
}
static u32 onecputick;
SIGPROF);
check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT], &virt_expires, utime,
SIGVTALRM);
- soft = ACCESS_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur);
+ soft = READ_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur);
if (soft != RLIM_INFINITY) {
unsigned long psecs = cputime_to_secs(ptime);
unsigned long hard =
- ACCESS_ONCE(sig->rlim[RLIMIT_CPU].rlim_max);
+ READ_ONCE(sig->rlim[RLIMIT_CPU].rlim_max);
cputime_t x;
if (psecs >= hard) {
/*
}
sig = tsk->signal;
- if (sig->cputimer.running) {
+ /* Check if cputimer is running. This is accessed without locking. */
+ if (READ_ONCE(sig->cputimer.running)) {
struct task_cputime group_sample;
- raw_spin_lock(&sig->cputimer.lock);
- group_sample = sig->cputimer.cputime;
- raw_spin_unlock(&sig->cputimer.lock);
+ sample_cputime_atomic(&group_sample, &sig->cputimer.cputime_atomic);
if (task_cputime_expired(&group_sample, &sig->cputime_expires))
return 1;
* If there are any active process wide timers (POSIX 1.b, itimers,
* RLIMIT_CPU) cputimer must be running.
*/
- if (tsk->signal->cputimer.running)
+ if (READ_ONCE(tsk->signal->cputimer.running))
check_process_timers(tsk, &firing);
/*
/* Update distances based on topology */
for_each_cpu(cpu, update_mask) {
if (cpu_rmap_copy_neigh(rmap, cpu,
- topology_thread_cpumask(cpu), 1))
+ topology_sibling_cpumask(cpu), 1))
continue;
if (cpu_rmap_copy_neigh(rmap, cpu,
topology_core_cpumask(cpu), 2))
#include <linux/string.h>
#include <linux/bitops.h>
#include <linux/rcupdate.h>
-#include <linux/preempt_mask.h> /* in_interrupt() */
+#include <linux/preempt.h> /* in_interrupt() */
/*
* @str: The string to measure.
* @count: Maximum count (including NUL character)
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Get the size of a NUL-terminated string in user space.
*
* strlen_user: - Get the size of a user string INCLUDING final NUL.
* @str: The string to measure.
*
- * Context: User context only. This function may sleep.
+ * Context: User context only. This function may sleep if pagefaults are
+ * enabled.
*
* Get the size of a NUL-terminated string in user space.
*
}
#if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP)
-void might_fault(void)
+void __might_fault(const char *file, int line)
{
/*
* Some code (nfs/sunrpc) uses socket ops on kernel memory while
*/
if (segment_eq(get_fs(), KERNEL_DS))
return;
-
- /*
- * it would be nicer only to annotate paths which are not under
- * pagefault_disable, however that requires a larger audit and
- * providing helpers like get_user_atomic.
- */
- if (in_atomic())
+ if (pagefault_disabled())
return;
-
- __might_sleep(__FILE__, __LINE__, 0);
-
+ __might_sleep(file, line, 0);
+#if defined(CONFIG_DEBUG_ATOMIC_SLEEP)
if (current->mm)
might_lock_read(¤t->mm->mmap_sem);
+#endif
}
-EXPORT_SYMBOL(might_fault);
+EXPORT_SYMBOL(__might_fault);
#endif
#if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLBFS)
projects / cascardo / linux.git / commitdiff