depends on SYSCTL
default y
+ config FHANDLE
+ bool "open by fhandle syscalls"
+ select EXPORTFS
+ help
+ If you say Y here, a user level program will be able to map
+ file names to handle and then later use the handle for
+ different file system operations. This is useful in implementing
+ userspace file servers, which now track files using handles instead
+ of names. The handle would remain the same even if file names
+ get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
+ syscalls.
+
+ config AUDIT
+ bool "Auditing support"
+ depends on NET
+ help
+ Enable auditing infrastructure that can be used with another
+ kernel subsystem, such as SELinux (which requires this for
+ logging of avc messages output). Does not do system-call
+ auditing without CONFIG_AUDITSYSCALL.
+
+ config AUDITSYSCALL
+ bool "Enable system-call auditing support"
+ depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH || (ARM && AEABI && !OABI_COMPAT))
+ default y if SECURITY_SELINUX
+ help
+ Enable low-overhead system-call auditing infrastructure that
+ can be used independently or with another kernel subsystem,
+ such as SELinux.
+
+ config AUDIT_WATCH
+ def_bool y
+ depends on AUDITSYSCALL
+ select FSNOTIFY
+
+ config AUDIT_TREE
+ def_bool y
+ depends on AUDITSYSCALL
+ select FSNOTIFY
+
+ config AUDIT_LOGINUID_IMMUTABLE
+ bool "Make audit loginuid immutable"
+ depends on AUDIT
+ help
+ The config option toggles if a task setting its loginuid requires
+ CAP_SYS_AUDITCONTROL or if that task should require no special permissions
+ but should instead only allow setting its loginuid if it was never
+ previously set. On systems which use systemd or a similar central
+ process to restart login services this should be set to true. On older
+ systems in which an admin would typically have to directly stop and
+ start processes this should be set to false. Setting this to true allows
+ one to drop potentially dangerous capabilites from the login tasks,
+ but may not be backwards compatible with older init systems.
+
+ source "kernel/irq/Kconfig"
+ source "kernel/time/Kconfig"
+
+ menu "CPU/Task time and stats accounting"
+
+ choice
+ prompt "Cputime accounting"
+ default TICK_CPU_ACCOUNTING if !PPC64
+ default VIRT_CPU_ACCOUNTING if PPC64
+
+ # Kind of a stub config for the pure tick based cputime accounting
+ config TICK_CPU_ACCOUNTING
+ bool "Simple tick based cputime accounting"
+ depends on !S390
+ help
+ This is the basic tick based cputime accounting that maintains
+ statistics about user, system and idle time spent on per jiffies
+ granularity.
+
+ If unsure, say Y.
+
+ config VIRT_CPU_ACCOUNTING
+ bool "Deterministic task and CPU time accounting"
+ depends on HAVE_VIRT_CPU_ACCOUNTING
+ help
+ Select this option to enable more accurate task and CPU time
+ accounting. This is done by reading a CPU counter on each
+ kernel entry and exit and on transitions within the kernel
+ between system, softirq and hardirq state, so there is a
+ small performance impact. In the case of s390 or IBM POWER > 5,
+ this also enables accounting of stolen time on logically-partitioned
+ systems.
+
+ config IRQ_TIME_ACCOUNTING
+ bool "Fine granularity task level IRQ time accounting"
+ depends on HAVE_IRQ_TIME_ACCOUNTING
+ help
+ Select this option to enable fine granularity task irq time
+ accounting. This is done by reading a timestamp on each
+ transitions between softirq and hardirq state, so there can be a
+ small performance impact.
+
+ If in doubt, say N here.
+
+ endchoice
+
config BSD_PROCESS_ACCT
bool "BSD Process Accounting"
help
for processing it. A preliminary version of these tools is available
at <http://www.gnu.org/software/acct/>.
- config FHANDLE
- bool "open by fhandle syscalls"
- select EXPORTFS
- help
- If you say Y here, a user level program will be able to map
- file names to handle and then later use the handle for
- different file system operations. This is useful in implementing
- userspace file servers, which now track files using handles instead
- of names. The handle would remain the same even if file names
- get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
- syscalls.
-
config TASKSTATS
bool "Export task/process statistics through netlink (EXPERIMENTAL)"
depends on NET
Say N if unsure.
- config AUDIT
- bool "Auditing support"
- depends on NET
- help
- Enable auditing infrastructure that can be used with another
- kernel subsystem, such as SELinux (which requires this for
- logging of avc messages output). Does not do system-call
- auditing without CONFIG_AUDITSYSCALL.
-
- config AUDITSYSCALL
- bool "Enable system-call auditing support"
- depends on AUDIT && (X86 || PPC || S390 || IA64 || UML || SPARC64 || SUPERH || (ARM && AEABI && !OABI_COMPAT))
- default y if SECURITY_SELINUX
- help
- Enable low-overhead system-call auditing infrastructure that
- can be used independently or with another kernel subsystem,
- such as SELinux.
-
- config AUDIT_WATCH
- def_bool y
- depends on AUDITSYSCALL
- select FSNOTIFY
-
- config AUDIT_TREE
- def_bool y
- depends on AUDITSYSCALL
- select FSNOTIFY
-
- config AUDIT_LOGINUID_IMMUTABLE
- bool "Make audit loginuid immutable"
- depends on AUDIT
- help
- The config option toggles if a task setting its loginuid requires
- CAP_SYS_AUDITCONTROL or if that task should require no special permissions
- but should instead only allow setting its loginuid if it was never
- previously set. On systems which use systemd or a similar central
- process to restart login services this should be set to true. On older
- systems in which an admin would typically have to directly stop and
- start processes this should be set to false. Setting this to true allows
- one to drop potentially dangerous capabilites from the login tasks,
- but may not be backwards compatible with older init systems.
-
- source "kernel/irq/Kconfig"
- source "kernel/time/Kconfig"
+ endmenu # "CPU/Task time and stats accounting"
menu "RCU Subsystem"
This option enables preemptible-RCU code that is common between
the TREE_PREEMPT_RCU and TINY_PREEMPT_RCU implementations.
+config RCU_USER_QS
+ bool "Consider userspace as in RCU extended quiescent state"
+ depends on HAVE_RCU_USER_QS && SMP
+ help
+ This option sets hooks on kernel / userspace boundaries and
+ puts RCU in extended quiescent state when the CPU runs in
+ userspace. It means that when a CPU runs in userspace, it is
+ excluded from the global RCU state machine and thus doesn't
+ to keep the timer tick on for RCU.
+
+config RCU_USER_QS_FORCE
+ bool "Force userspace extended QS by default"
+ depends on RCU_USER_QS
+ help
+ Set the hooks in user/kernel boundaries by default in order to
+ test this feature that treats userspace as an extended quiescent
+ state until we have a real user like a full adaptive nohz option.
+
config RCU_FANOUT
int "Tree-based hierarchical RCU fanout value"
range 2 64 if 64BIT
dequeue_task(rq, p, flags);
}
- #ifdef CONFIG_IRQ_TIME_ACCOUNTING
-
- /*
- * There are no locks covering percpu hardirq/softirq time.
- * They are only modified in account_system_vtime, on corresponding CPU
- * with interrupts disabled. So, writes are safe.
- * They are read and saved off onto struct rq in update_rq_clock().
- * This may result in other CPU reading this CPU's irq time and can
- * race with irq/account_system_vtime on this CPU. We would either get old
- * or new value with a side effect of accounting a slice of irq time to wrong
- * task when irq is in progress while we read rq->clock. That is a worthy
- * compromise in place of having locks on each irq in account_system_time.
- */
- static DEFINE_PER_CPU(u64, cpu_hardirq_time);
- static DEFINE_PER_CPU(u64, cpu_softirq_time);
-
- static DEFINE_PER_CPU(u64, irq_start_time);
- static int sched_clock_irqtime;
-
- void enable_sched_clock_irqtime(void)
- {
- sched_clock_irqtime = 1;
- }
-
- void disable_sched_clock_irqtime(void)
- {
- sched_clock_irqtime = 0;
- }
-
- #ifndef CONFIG_64BIT
- static DEFINE_PER_CPU(seqcount_t, irq_time_seq);
-
- static inline void irq_time_write_begin(void)
- {
- __this_cpu_inc(irq_time_seq.sequence);
- smp_wmb();
- }
-
- static inline void irq_time_write_end(void)
- {
- smp_wmb();
- __this_cpu_inc(irq_time_seq.sequence);
- }
-
- static inline u64 irq_time_read(int cpu)
- {
- u64 irq_time;
- unsigned seq;
-
- do {
- seq = read_seqcount_begin(&per_cpu(irq_time_seq, cpu));
- irq_time = per_cpu(cpu_softirq_time, cpu) +
- per_cpu(cpu_hardirq_time, cpu);
- } while (read_seqcount_retry(&per_cpu(irq_time_seq, cpu), seq));
-
- return irq_time;
- }
- #else /* CONFIG_64BIT */
- static inline void irq_time_write_begin(void)
- {
- }
-
- static inline void irq_time_write_end(void)
- {
- }
-
- static inline u64 irq_time_read(int cpu)
- {
- return per_cpu(cpu_softirq_time, cpu) + per_cpu(cpu_hardirq_time, cpu);
- }
- #endif /* CONFIG_64BIT */
-
- /*
- * Called before incrementing preempt_count on {soft,}irq_enter
- * and before decrementing preempt_count on {soft,}irq_exit.
- */
- void account_system_vtime(struct task_struct *curr)
- {
- unsigned long flags;
- s64 delta;
- int cpu;
-
- if (!sched_clock_irqtime)
- return;
-
- local_irq_save(flags);
-
- cpu = smp_processor_id();
- delta = sched_clock_cpu(cpu) - __this_cpu_read(irq_start_time);
- __this_cpu_add(irq_start_time, delta);
-
- irq_time_write_begin();
- /*
- * We do not account for softirq time from ksoftirqd here.
- * We want to continue accounting softirq time to ksoftirqd thread
- * in that case, so as not to confuse scheduler with a special task
- * that do not consume any time, but still wants to run.
- */
- if (hardirq_count())
- __this_cpu_add(cpu_hardirq_time, delta);
- else if (in_serving_softirq() && curr != this_cpu_ksoftirqd())
- __this_cpu_add(cpu_softirq_time, delta);
-
- irq_time_write_end();
- local_irq_restore(flags);
- }
- EXPORT_SYMBOL_GPL(account_system_vtime);
-
- #endif /* CONFIG_IRQ_TIME_ACCOUNTING */
-
- #ifdef CONFIG_PARAVIRT
- static inline u64 steal_ticks(u64 steal)
- {
- if (unlikely(steal > NSEC_PER_SEC))
- return div_u64(steal, TICK_NSEC);
-
- return __iter_div_u64_rem(steal, TICK_NSEC, &steal);
- }
- #endif
-
static void update_rq_clock_task(struct rq *rq, s64 delta)
{
/*
#endif
}
- #ifdef CONFIG_IRQ_TIME_ACCOUNTING
- static int irqtime_account_hi_update(void)
- {
- u64 *cpustat = kcpustat_this_cpu->cpustat;
- unsigned long flags;
- u64 latest_ns;
- int ret = 0;
-
- local_irq_save(flags);
- latest_ns = this_cpu_read(cpu_hardirq_time);
- if (nsecs_to_cputime64(latest_ns) > cpustat[CPUTIME_IRQ])
- ret = 1;
- local_irq_restore(flags);
- return ret;
- }
-
- static int irqtime_account_si_update(void)
- {
- u64 *cpustat = kcpustat_this_cpu->cpustat;
- unsigned long flags;
- u64 latest_ns;
- int ret = 0;
-
- local_irq_save(flags);
- latest_ns = this_cpu_read(cpu_softirq_time);
- if (nsecs_to_cputime64(latest_ns) > cpustat[CPUTIME_SOFTIRQ])
- ret = 1;
- local_irq_restore(flags);
- return ret;
- }
-
- #else /* CONFIG_IRQ_TIME_ACCOUNTING */
-
- #define sched_clock_irqtime (0)
-
- #endif
-
void sched_set_stop_task(int cpu, struct task_struct *stop)
{
struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
smp_send_reschedule(cpu);
}
- #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
- static int ttwu_activate_remote(struct task_struct *p, int wake_flags)
- {
- struct rq *rq;
- int ret = 0;
-
- rq = __task_rq_lock(p);
- if (p->on_cpu) {
- ttwu_activate(rq, p, ENQUEUE_WAKEUP);
- ttwu_do_wakeup(rq, p, wake_flags);
- ret = 1;
- }
- __task_rq_unlock(rq);
-
- return ret;
-
- }
- #endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */
-
bool cpus_share_cache(int this_cpu, int that_cpu)
{
return per_cpu(sd_llc_id, this_cpu) == per_cpu(sd_llc_id, that_cpu);
* If the owning (remote) cpu is still in the middle of schedule() with
* this task as prev, wait until its done referencing the task.
*/
- while (p->on_cpu) {
- #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
- /*
- * In case the architecture enables interrupts in
- * context_switch(), we cannot busy wait, since that
- * would lead to deadlocks when an interrupt hits and
- * tries to wake up @prev. So bail and do a complete
- * remote wakeup.
- */
- if (ttwu_activate_remote(p, wake_flags))
- goto stat;
- #else
+ while (p->on_cpu)
cpu_relax();
- #endif
- }
/*
* Pairs with the smp_wmb() in finish_lock_switch().
*/
* Manfred Spraul <manfred@colorfullife.com>
*/
prev_state = prev->state;
+ vtime_task_switch(prev);
finish_arch_switch(prev);
- #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
- local_irq_disable();
- #endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */
perf_event_task_sched_in(prev, current);
- #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
- local_irq_enable();
- #endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */
finish_lock_switch(rq, prev);
finish_arch_post_lock_switch();
#endif
/* Here we just switch the register state and the stack. */
+ rcu_switch(prev, next);
switch_to(prev, next, prev);
barrier();
return ns;
}
- #ifdef CONFIG_CGROUP_CPUACCT
- struct cgroup_subsys cpuacct_subsys;
- struct cpuacct root_cpuacct;
- #endif
-
- static inline void task_group_account_field(struct task_struct *p, int index,
- u64 tmp)
- {
- #ifdef CONFIG_CGROUP_CPUACCT
- struct kernel_cpustat *kcpustat;
- struct cpuacct *ca;
- #endif
- /*
- * Since all updates are sure to touch the root cgroup, we
- * get ourselves ahead and touch it first. If the root cgroup
- * is the only cgroup, then nothing else should be necessary.
- *
- */
- __get_cpu_var(kernel_cpustat).cpustat[index] += tmp;
-
- #ifdef CONFIG_CGROUP_CPUACCT
- if (unlikely(!cpuacct_subsys.active))
- return;
-
- rcu_read_lock();
- ca = task_ca(p);
- while (ca && (ca != &root_cpuacct)) {
- kcpustat = this_cpu_ptr(ca->cpustat);
- kcpustat->cpustat[index] += tmp;
- ca = parent_ca(ca);
- }
- rcu_read_unlock();
- #endif
- }
-
-
- /*
- * Account user cpu time to a process.
- * @p: the process that the cpu time gets accounted to
- * @cputime: the cpu time spent in user space since the last update
- * @cputime_scaled: cputime scaled by cpu frequency
- */
- void account_user_time(struct task_struct *p, cputime_t cputime,
- cputime_t cputime_scaled)
- {
- int index;
-
- /* Add user time to process. */
- p->utime += cputime;
- p->utimescaled += cputime_scaled;
- account_group_user_time(p, cputime);
-
- index = (TASK_NICE(p) > 0) ? CPUTIME_NICE : CPUTIME_USER;
-
- /* Add user time to cpustat. */
- task_group_account_field(p, index, (__force u64) cputime);
-
- /* Account for user time used */
- acct_update_integrals(p);
- }
-
- /*
- * Account guest cpu time to a process.
- * @p: the process that the cpu time gets accounted to
- * @cputime: the cpu time spent in virtual machine since the last update
- * @cputime_scaled: cputime scaled by cpu frequency
- */
- static void account_guest_time(struct task_struct *p, cputime_t cputime,
- cputime_t cputime_scaled)
- {
- u64 *cpustat = kcpustat_this_cpu->cpustat;
-
- /* Add guest time to process. */
- p->utime += cputime;
- p->utimescaled += cputime_scaled;
- account_group_user_time(p, cputime);
- p->gtime += cputime;
-
- /* Add guest time to cpustat. */
- if (TASK_NICE(p) > 0) {
- cpustat[CPUTIME_NICE] += (__force u64) cputime;
- cpustat[CPUTIME_GUEST_NICE] += (__force u64) cputime;
- } else {
- cpustat[CPUTIME_USER] += (__force u64) cputime;
- cpustat[CPUTIME_GUEST] += (__force u64) cputime;
- }
- }
-
- /*
- * Account system cpu time to a process and desired cpustat field
- * @p: the process that the cpu time gets accounted to
- * @cputime: the cpu time spent in kernel space since the last update
- * @cputime_scaled: cputime scaled by cpu frequency
- * @target_cputime64: pointer to cpustat field that has to be updated
- */
- static inline
- void __account_system_time(struct task_struct *p, cputime_t cputime,
- cputime_t cputime_scaled, int index)
- {
- /* Add system time to process. */
- p->stime += cputime;
- p->stimescaled += cputime_scaled;
- account_group_system_time(p, cputime);
-
- /* Add system time to cpustat. */
- task_group_account_field(p, index, (__force u64) cputime);
-
- /* Account for system time used */
- acct_update_integrals(p);
- }
-
- /*
- * Account system cpu time to a process.
- * @p: the process that the cpu time gets accounted to
- * @hardirq_offset: the offset to subtract from hardirq_count()
- * @cputime: the cpu time spent in kernel space since the last update
- * @cputime_scaled: cputime scaled by cpu frequency
- */
- void account_system_time(struct task_struct *p, int hardirq_offset,
- cputime_t cputime, cputime_t cputime_scaled)
- {
- int index;
-
- if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0)) {
- account_guest_time(p, cputime, cputime_scaled);
- return;
- }
-
- if (hardirq_count() - hardirq_offset)
- index = CPUTIME_IRQ;
- else if (in_serving_softirq())
- index = CPUTIME_SOFTIRQ;
- else
- index = CPUTIME_SYSTEM;
-
- __account_system_time(p, cputime, cputime_scaled, index);
- }
-
- /*
- * Account for involuntary wait time.
- * @cputime: the cpu time spent in involuntary wait
- */
- void account_steal_time(cputime_t cputime)
- {
- u64 *cpustat = kcpustat_this_cpu->cpustat;
-
- cpustat[CPUTIME_STEAL] += (__force u64) cputime;
- }
-
- /*
- * Account for idle time.
- * @cputime: the cpu time spent in idle wait
- */
- void account_idle_time(cputime_t cputime)
- {
- u64 *cpustat = kcpustat_this_cpu->cpustat;
- struct rq *rq = this_rq();
-
- if (atomic_read(&rq->nr_iowait) > 0)
- cpustat[CPUTIME_IOWAIT] += (__force u64) cputime;
- else
- cpustat[CPUTIME_IDLE] += (__force u64) cputime;
- }
-
- static __always_inline bool steal_account_process_tick(void)
- {
- #ifdef CONFIG_PARAVIRT
- if (static_key_false(¶virt_steal_enabled)) {
- u64 steal, st = 0;
-
- steal = paravirt_steal_clock(smp_processor_id());
- steal -= this_rq()->prev_steal_time;
-
- st = steal_ticks(steal);
- this_rq()->prev_steal_time += st * TICK_NSEC;
-
- account_steal_time(st);
- return st;
- }
- #endif
- return false;
- }
-
- #ifndef CONFIG_VIRT_CPU_ACCOUNTING
-
- #ifdef CONFIG_IRQ_TIME_ACCOUNTING
- /*
- * Account a tick to a process and cpustat
- * @p: the process that the cpu time gets accounted to
- * @user_tick: is the tick from userspace
- * @rq: the pointer to rq
- *
- * Tick demultiplexing follows the order
- * - pending hardirq update
- * - pending softirq update
- * - user_time
- * - idle_time
- * - system time
- * - check for guest_time
- * - else account as system_time
- *
- * Check for hardirq is done both for system and user time as there is
- * no timer going off while we are on hardirq and hence we may never get an
- * opportunity to update it solely in system time.
- * p->stime and friends are only updated on system time and not on irq
- * softirq as those do not count in task exec_runtime any more.
- */
- static void irqtime_account_process_tick(struct task_struct *p, int user_tick,
- struct rq *rq)
- {
- cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy);
- u64 *cpustat = kcpustat_this_cpu->cpustat;
-
- if (steal_account_process_tick())
- return;
-
- if (irqtime_account_hi_update()) {
- cpustat[CPUTIME_IRQ] += (__force u64) cputime_one_jiffy;
- } else if (irqtime_account_si_update()) {
- cpustat[CPUTIME_SOFTIRQ] += (__force u64) cputime_one_jiffy;
- } else if (this_cpu_ksoftirqd() == p) {
- /*
- * ksoftirqd time do not get accounted in cpu_softirq_time.
- * So, we have to handle it separately here.
- * Also, p->stime needs to be updated for ksoftirqd.
- */
- __account_system_time(p, cputime_one_jiffy, one_jiffy_scaled,
- CPUTIME_SOFTIRQ);
- } else if (user_tick) {
- account_user_time(p, cputime_one_jiffy, one_jiffy_scaled);
- } else if (p == rq->idle) {
- account_idle_time(cputime_one_jiffy);
- } else if (p->flags & PF_VCPU) { /* System time or guest time */
- account_guest_time(p, cputime_one_jiffy, one_jiffy_scaled);
- } else {
- __account_system_time(p, cputime_one_jiffy, one_jiffy_scaled,
- CPUTIME_SYSTEM);
- }
- }
-
- static void irqtime_account_idle_ticks(int ticks)
- {
- int i;
- struct rq *rq = this_rq();
-
- for (i = 0; i < ticks; i++)
- irqtime_account_process_tick(current, 0, rq);
- }
- #else /* CONFIG_IRQ_TIME_ACCOUNTING */
- static void irqtime_account_idle_ticks(int ticks) {}
- static void irqtime_account_process_tick(struct task_struct *p, int user_tick,
- struct rq *rq) {}
- #endif /* CONFIG_IRQ_TIME_ACCOUNTING */
-
- /*
- * Account a single tick of cpu time.
- * @p: the process that the cpu time gets accounted to
- * @user_tick: indicates if the tick is a user or a system tick
- */
- void account_process_tick(struct task_struct *p, int user_tick)
- {
- cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy);
- struct rq *rq = this_rq();
-
- if (sched_clock_irqtime) {
- irqtime_account_process_tick(p, user_tick, rq);
- return;
- }
-
- if (steal_account_process_tick())
- return;
-
- if (user_tick)
- account_user_time(p, cputime_one_jiffy, one_jiffy_scaled);
- else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET))
- account_system_time(p, HARDIRQ_OFFSET, cputime_one_jiffy,
- one_jiffy_scaled);
- else
- account_idle_time(cputime_one_jiffy);
- }
-
- /*
- * Account multiple ticks of steal time.
- * @p: the process from which the cpu time has been stolen
- * @ticks: number of stolen ticks
- */
- void account_steal_ticks(unsigned long ticks)
- {
- account_steal_time(jiffies_to_cputime(ticks));
- }
-
- /*
- * Account multiple ticks of idle time.
- * @ticks: number of stolen ticks
- */
- void account_idle_ticks(unsigned long ticks)
- {
-
- if (sched_clock_irqtime) {
- irqtime_account_idle_ticks(ticks);
- return;
- }
-
- account_idle_time(jiffies_to_cputime(ticks));
- }
-
- #endif
-
- /*
- * Use precise platform statistics if available:
- */
- #ifdef CONFIG_VIRT_CPU_ACCOUNTING
- void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
- {
- *ut = p->utime;
- *st = p->stime;
- }
-
- void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
- {
- struct task_cputime cputime;
-
- thread_group_cputime(p, &cputime);
-
- *ut = cputime.utime;
- *st = cputime.stime;
- }
- #else
-
- #ifndef nsecs_to_cputime
- # define nsecs_to_cputime(__nsecs) nsecs_to_jiffies(__nsecs)
- #endif
-
- static cputime_t scale_utime(cputime_t utime, cputime_t rtime, cputime_t total)
- {
- u64 temp = (__force u64) rtime;
-
- temp *= (__force u64) utime;
-
- if (sizeof(cputime_t) == 4)
- temp = div_u64(temp, (__force u32) total);
- else
- temp = div64_u64(temp, (__force u64) total);
-
- return (__force cputime_t) temp;
- }
-
- void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
- {
- cputime_t rtime, utime = p->utime, total = utime + p->stime;
-
- /*
- * Use CFS's precise accounting:
- */
- rtime = nsecs_to_cputime(p->se.sum_exec_runtime);
-
- if (total)
- utime = scale_utime(utime, rtime, total);
- else
- utime = rtime;
-
- /*
- * Compare with previous values, to keep monotonicity:
- */
- p->prev_utime = max(p->prev_utime, utime);
- p->prev_stime = max(p->prev_stime, rtime - p->prev_utime);
-
- *ut = p->prev_utime;
- *st = p->prev_stime;
- }
-
- /*
- * Must be called with siglock held.
- */
- void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
- {
- struct signal_struct *sig = p->signal;
- struct task_cputime cputime;
- cputime_t rtime, utime, total;
-
- thread_group_cputime(p, &cputime);
-
- total = cputime.utime + cputime.stime;
- rtime = nsecs_to_cputime(cputime.sum_exec_runtime);
-
- if (total)
- utime = scale_utime(cputime.utime, rtime, total);
- else
- utime = rtime;
-
- sig->prev_utime = max(sig->prev_utime, utime);
- sig->prev_stime = max(sig->prev_stime, rtime - sig->prev_utime);
-
- *ut = sig->prev_utime;
- *st = sig->prev_stime;
- }
- #endif
-
/*
* This function gets called by the timer code, with HZ frequency.
* We call it with interrupts disabled.
/*
* __schedule() is the main scheduler function.
+ *
+ * The main means of driving the scheduler and thus entering this function are:
+ *
+ * 1. Explicit blocking: mutex, semaphore, waitqueue, etc.
+ *
+ * 2. TIF_NEED_RESCHED flag is checked on interrupt and userspace return
+ * paths. For example, see arch/x86/entry_64.S.
+ *
+ * To drive preemption between tasks, the scheduler sets the flag in timer
+ * interrupt handler scheduler_tick().
+ *
+ * 3. Wakeups don't really cause entry into schedule(). They add a
+ * task to the run-queue and that's it.
+ *
+ * Now, if the new task added to the run-queue preempts the current
+ * task, then the wakeup sets TIF_NEED_RESCHED and schedule() gets
+ * called on the nearest possible occasion:
+ *
+ * - If the kernel is preemptible (CONFIG_PREEMPT=y):
+ *
+ * - in syscall or exception context, at the next outmost
+ * preempt_enable(). (this might be as soon as the wake_up()'s
+ * spin_unlock()!)
+ *
+ * - in IRQ context, return from interrupt-handler to
+ * preemptible context
+ *
+ * - If the kernel is not preemptible (CONFIG_PREEMPT is not set)
+ * then at the next:
+ *
+ * - cond_resched() call
+ * - explicit schedule() call
+ * - return from syscall or exception to user-space
+ * - return from interrupt-handler to user-space
*/
static void __sched __schedule(void)
{
}
EXPORT_SYMBOL(schedule);
+#ifdef CONFIG_RCU_USER_QS
+asmlinkage void __sched schedule_user(void)
+{
+ /*
+ * If we come here after a random call to set_need_resched(),
+ * or we have been woken up remotely but the IPI has not yet arrived,
+ * we haven't yet exited the RCU idle mode. Do it here manually until
+ * we find a better solution.
+ */
+ rcu_user_exit();
+ schedule();
+ rcu_user_enter();
+}
+#endif
+
/**
* schedule_preempt_disabled - called with preemption disabled
*
/* Catch callers which need to be fixed */
BUG_ON(ti->preempt_count || !irqs_disabled());
+ rcu_user_exit();
do {
add_preempt_count(PREEMPT_ACTIVE);
local_irq_enable();
*/
if (preempt && rq != p_rq)
resched_task(p_rq->curr);
- } else {
- /*
- * We might have set it in task_yield_fair(), but are
- * not going to schedule(), so don't want to skip
- * the next update.
- */
- rq->skip_clock_update = 0;
}
out:
*tablep = NULL;
}
+ static int min_load_idx = 0;
+ static int max_load_idx = CPU_LOAD_IDX_MAX;
+
static void
set_table_entry(struct ctl_table *entry,
const char *procname, void *data, int maxlen,
- umode_t mode, proc_handler *proc_handler)
+ umode_t mode, proc_handler *proc_handler,
+ bool load_idx)
{
entry->procname = procname;
entry->data = data;
entry->maxlen = maxlen;
entry->mode = mode;
entry->proc_handler = proc_handler;
+
+ if (load_idx) {
+ entry->extra1 = &min_load_idx;
+ entry->extra2 = &max_load_idx;
+ }
}
static struct ctl_table *
return NULL;
set_table_entry(&table[0], "min_interval", &sd->min_interval,
- sizeof(long), 0644, proc_doulongvec_minmax);
+ sizeof(long), 0644, proc_doulongvec_minmax, false);
set_table_entry(&table[1], "max_interval", &sd->max_interval,
- sizeof(long), 0644, proc_doulongvec_minmax);
+ sizeof(long), 0644, proc_doulongvec_minmax, false);
set_table_entry(&table[2], "busy_idx", &sd->busy_idx,
- sizeof(int), 0644, proc_dointvec_minmax);
+ sizeof(int), 0644, proc_dointvec_minmax, true);
set_table_entry(&table[3], "idle_idx", &sd->idle_idx,
- sizeof(int), 0644, proc_dointvec_minmax);
+ sizeof(int), 0644, proc_dointvec_minmax, true);
set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx,
- sizeof(int), 0644, proc_dointvec_minmax);
+ sizeof(int), 0644, proc_dointvec_minmax, true);
set_table_entry(&table[5], "wake_idx", &sd->wake_idx,
- sizeof(int), 0644, proc_dointvec_minmax);
+ sizeof(int), 0644, proc_dointvec_minmax, true);
set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx,
- sizeof(int), 0644, proc_dointvec_minmax);
+ sizeof(int), 0644, proc_dointvec_minmax, true);
set_table_entry(&table[7], "busy_factor", &sd->busy_factor,
- sizeof(int), 0644, proc_dointvec_minmax);
+ sizeof(int), 0644, proc_dointvec_minmax, false);
set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct,
- sizeof(int), 0644, proc_dointvec_minmax);
+ sizeof(int), 0644, proc_dointvec_minmax, false);
set_table_entry(&table[9], "cache_nice_tries",
&sd->cache_nice_tries,
- sizeof(int), 0644, proc_dointvec_minmax);
+ sizeof(int), 0644, proc_dointvec_minmax, false);
set_table_entry(&table[10], "flags", &sd->flags,
- sizeof(int), 0644, proc_dointvec_minmax);
+ sizeof(int), 0644, proc_dointvec_minmax, false);
set_table_entry(&table[11], "name", sd->name,
- CORENAME_MAX_SIZE, 0444, proc_dostring);
+ CORENAME_MAX_SIZE, 0444, proc_dostring, false);
/* &table[12] is terminator */
return table;
* SD_SHARE_PKG_RESOURCE set (Last Level Cache Domain) for this
* allows us to avoid some pointer chasing select_idle_sibling().
*
- * Iterate domains and sched_groups downward, assigning CPUs to be
- * select_idle_sibling() hw buddy. Cross-wiring hw makes bouncing
- * due to random perturbation self canceling, ie sw buddies pull
- * their counterpart to their CPU's hw counterpart.
- *
* Also keep a unique ID per domain (we use the first cpu number in
* the cpumask of the domain), this allows us to quickly tell if
* two cpus are in the same cache domain, see cpus_share_cache().
int id = cpu;
sd = highest_flag_domain(cpu, SD_SHARE_PKG_RESOURCES);
- if (sd) {
- struct sched_domain *tmp = sd;
- struct sched_group *sg, *prev;
- bool right;
-
- /*
- * Traverse to first CPU in group, and count hops
- * to cpu from there, switching direction on each
- * hop, never ever pointing the last CPU rightward.
- */
- do {
- id = cpumask_first(sched_domain_span(tmp));
- prev = sg = tmp->groups;
- right = 1;
-
- while (cpumask_first(sched_group_cpus(sg)) != id)
- sg = sg->next;
-
- while (!cpumask_test_cpu(cpu, sched_group_cpus(sg))) {
- prev = sg;
- sg = sg->next;
- right = !right;
- }
-
- /* A CPU went down, never point back to domain start. */
- if (right && cpumask_first(sched_group_cpus(sg->next)) == id)
- right = false;
-
- sg = right ? sg->next : prev;
- tmp->idle_buddy = cpumask_first(sched_group_cpus(sg));
- } while ((tmp = tmp->child));
-
+ if (sd)
id = cpumask_first(sched_domain_span(sd));
- }
rcu_assign_pointer(per_cpu(sd_llc, cpu), sd);
per_cpu(sd_llc_id, cpu) = id;
| 0*SD_BALANCE_FORK
| 0*SD_BALANCE_WAKE
| 0*SD_WAKE_AFFINE
- | 0*SD_PREFER_LOCAL
| 0*SD_SHARE_CPUPOWER
| 0*SD_SHARE_PKG_RESOURCES
| 1*SD_SERIALIZE
* (balbir@in.ibm.com).
*/
+ struct cpuacct root_cpuacct;
+
/* create a new cpu accounting group */
static struct cgroup_subsys_state *cpuacct_create(struct cgroup *cgrp)
{
/*
* The idea is to set a period in which each task runs once.
*
- * When there are too many tasks (sysctl_sched_nr_latency) we have to stretch
+ * When there are too many tasks (sched_nr_latency) we have to stretch
* this period because otherwise the slices get too small.
*
* p = (nr <= nl) ? l : l*nr/nl
int cpu = smp_processor_id();
int prev_cpu = task_cpu(p);
struct sched_domain *sd;
+ struct sched_group *sg;
+ int i;
/*
* If the task is going to be woken-up on this cpu and if it is
return prev_cpu;
/*
- * Otherwise, check assigned siblings to find an elegible idle cpu.
+ * Otherwise, iterate the domains and find an elegible idle cpu.
*/
sd = rcu_dereference(per_cpu(sd_llc, target));
-
for_each_lower_domain(sd) {
- if (!cpumask_test_cpu(sd->idle_buddy, tsk_cpus_allowed(p)))
- continue;
- if (idle_cpu(sd->idle_buddy))
- return sd->idle_buddy;
- }
+ sg = sd->groups;
+ do {
+ if (!cpumask_intersects(sched_group_cpus(sg),
+ tsk_cpus_allowed(p)))
+ goto next;
+
+ for_each_cpu(i, sched_group_cpus(sg)) {
+ if (!idle_cpu(i))
+ goto next;
+ }
+ target = cpumask_first_and(sched_group_cpus(sg),
+ tsk_cpus_allowed(p));
+ goto done;
+next:
+ sg = sg->next;
+ } while (sg != sd->groups);
+ }
+done:
return target;
}
int prev_cpu = task_cpu(p);
int new_cpu = cpu;
int want_affine = 0;
- int want_sd = 1;
int sync = wake_flags & WF_SYNC;
if (p->nr_cpus_allowed == 1)
if (!(tmp->flags & SD_LOAD_BALANCE))
continue;
- /*
- * If power savings logic is enabled for a domain, see if we
- * are not overloaded, if so, don't balance wider.
- */
- if (tmp->flags & (SD_PREFER_LOCAL)) {
- unsigned long power = 0;
- unsigned long nr_running = 0;
- unsigned long capacity;
- int i;
-
- for_each_cpu(i, sched_domain_span(tmp)) {
- power += power_of(i);
- nr_running += cpu_rq(i)->cfs.nr_running;
- }
-
- capacity = DIV_ROUND_CLOSEST(power, SCHED_POWER_SCALE);
-
- if (nr_running < capacity)
- want_sd = 0;
- }
-
/*
* If both cpu and prev_cpu are part of this domain,
* cpu is a valid SD_WAKE_AFFINE target.
if (want_affine && (tmp->flags & SD_WAKE_AFFINE) &&
cpumask_test_cpu(prev_cpu, sched_domain_span(tmp))) {
affine_sd = tmp;
- want_affine = 0;
- }
-
- if (!want_sd && !want_affine)
break;
+ }
- if (!(tmp->flags & sd_flag))
- continue;
-
- if (want_sd)
+ if (tmp->flags & sd_flag)
sd = tmp;
}
if (affine_sd) {
- if (cpu == prev_cpu || wake_affine(affine_sd, p, sync))
+ if (cpu != prev_cpu && wake_affine(affine_sd, p, sync))
prev_cpu = cpu;
new_cpu = select_idle_sibling(p, prev_cpu);
goto out_balanced;
}
- BUG_ON(busiest == this_rq);
+ BUG_ON(busiest == env.dst_rq);
schedstat_add(sd, lb_imbalance[idle], env.imbalance);
update_h_load(env.src_cpu);
more_balance:
local_irq_save(flags);
- double_rq_lock(this_rq, busiest);
+ double_rq_lock(env.dst_rq, busiest);
/*
* cur_ld_moved - load moved in current iteration
*/
cur_ld_moved = move_tasks(&env);
ld_moved += cur_ld_moved;
- double_rq_unlock(this_rq, busiest);
+ double_rq_unlock(env.dst_rq, busiest);
local_irq_restore(flags);
if (env.flags & LBF_NEED_BREAK) {
if ((env.flags & LBF_SOME_PINNED) && env.imbalance > 0 &&
lb_iterations++ < max_lb_iterations) {
- this_rq = cpu_rq(env.new_dst_cpu);
- env.dst_rq = this_rq;
+ env.dst_rq = cpu_rq(env.new_dst_cpu);
env.dst_cpu = env.new_dst_cpu;
env.flags &= ~LBF_SOME_PINNED;
env.loop = 0;
return;
}
- static inline void clear_nohz_tick_stopped(int cpu)
+ static inline void nohz_balance_exit_idle(int cpu)
{
if (unlikely(test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))) {
cpumask_clear_cpu(cpu, nohz.idle_cpus_mask);
}
/*
- * This routine will record that this cpu is going idle with tick stopped.
+ * This routine will record that the cpu is going idle with tick stopped.
* This info will be used in performing idle load balancing in the future.
*/
- void select_nohz_load_balancer(int stop_tick)
+ void nohz_balance_enter_idle(int cpu)
{
- int cpu = smp_processor_id();
-
/*
* If this cpu is going down, then nothing needs to be done.
*/
if (!cpu_active(cpu))
return;
- if (stop_tick) {
- if (test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))
- return;
+ if (test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))
+ return;
- cpumask_set_cpu(cpu, nohz.idle_cpus_mask);
- atomic_inc(&nohz.nr_cpus);
- set_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu));
- }
- return;
+ cpumask_set_cpu(cpu, nohz.idle_cpus_mask);
+ atomic_inc(&nohz.nr_cpus);
+ set_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu));
}
static int __cpuinit sched_ilb_notifier(struct notifier_block *nfb,
{
switch (action & ~CPU_TASKS_FROZEN) {
case CPU_DYING:
- clear_nohz_tick_stopped(smp_processor_id());
+ nohz_balance_exit_idle(smp_processor_id());
return NOTIFY_OK;
default:
return NOTIFY_DONE;
if (need_resched())
break;
- raw_spin_lock_irq(&this_rq->lock);
- update_rq_clock(this_rq);
- update_idle_cpu_load(this_rq);
- raw_spin_unlock_irq(&this_rq->lock);
+ rq = cpu_rq(balance_cpu);
+
+ raw_spin_lock_irq(&rq->lock);
+ update_rq_clock(rq);
+ update_idle_cpu_load(rq);
+ raw_spin_unlock_irq(&rq->lock);
rebalance_domains(balance_cpu, CPU_IDLE);
- rq = cpu_rq(balance_cpu);
if (time_after(this_rq->next_balance, rq->next_balance))
this_rq->next_balance = rq->next_balance;
}
* busy tick after returning from idle, we will update the busy stats.
*/
set_cpu_sd_state_busy();
- clear_nohz_tick_stopped(cpu);
+ nohz_balance_exit_idle(cpu);
/*
* None are in tickless mode and hence no need for NOHZ idle load
projects / cascardo / linux.git / commitdiff