return data.ret;
}
+static void event_function_call(struct perf_event *event,
+ int (*active)(void *),
+ void (*inactive)(void *),
+ void *data)
+{
+ struct perf_event_context *ctx = event->ctx;
+ struct task_struct *task = ctx->task;
+
+ if (!task) {
+ cpu_function_call(event->cpu, active, data);
+ return;
+ }
+
+again:
+ if (!task_function_call(task, active, data))
+ return;
+
+ raw_spin_lock_irq(&ctx->lock);
+ if (ctx->is_active) {
+ /*
+ * Reload the task pointer, it might have been changed by
+ * a concurrent perf_event_context_sched_out().
+ */
+ task = ctx->task;
+ raw_spin_unlock_irq(&ctx->lock);
+ goto again;
+ }
+ inactive(data);
+ raw_spin_unlock_irq(&ctx->lock);
+}
+
#define EVENT_OWNER_KERNEL ((void *) -1)
static bool is_kernel_event(struct perf_event *event)
bool detach_group;
};
+static void ___perf_remove_from_context(void *info)
+{
+ struct remove_event *re = info;
+ struct perf_event *event = re->event;
+ struct perf_event_context *ctx = event->ctx;
+
+ if (re->detach_group)
+ perf_group_detach(event);
+ list_del_event(event, ctx);
+}
+
/*
* Cross CPU call to remove a performance event
*
return 0;
}
-
/*
* Remove the event from a task's (or a CPU's) list of events.
*
static void perf_remove_from_context(struct perf_event *event, bool detach_group)
{
struct perf_event_context *ctx = event->ctx;
- struct task_struct *task = ctx->task;
struct remove_event re = {
.event = event,
.detach_group = detach_group,
lockdep_assert_held(&ctx->mutex);
- if (!task) {
- /*
- * Per cpu events are removed via an smp call. The removal can
- * fail if the CPU is currently offline, but in that case we
- * already called __perf_remove_from_context from
- * perf_event_exit_cpu.
- */
- cpu_function_call(event->cpu, __perf_remove_from_context, &re);
- return;
- }
-
-retry:
- if (!task_function_call(task, __perf_remove_from_context, &re))
- return;
-
- raw_spin_lock_irq(&ctx->lock);
- /*
- * If we failed to find a running task, but find the context active now
- * that we've acquired the ctx->lock, retry.
- */
- if (ctx->is_active) {
- raw_spin_unlock_irq(&ctx->lock);
- /*
- * Reload the task pointer, it might have been changed by
- * a concurrent perf_event_context_sched_out().
- */
- task = ctx->task;
- goto retry;
- }
-
- /*
- * Since the task isn't running, its safe to remove the event, us
- * holding the ctx->lock ensures the task won't get scheduled in.
- */
- if (detach_group)
- perf_group_detach(event);
- list_del_event(event, ctx);
- raw_spin_unlock_irq(&ctx->lock);
+ event_function_call(event, __perf_remove_from_context,
+ ___perf_remove_from_context, &re);
}
/*
return 0;
}
+void ___perf_event_disable(void *info)
+{
+ struct perf_event *event = info;
+
+ /*
+ * Since we have the lock this context can't be scheduled
+ * in, so we can change the state safely.
+ */
+ if (event->state == PERF_EVENT_STATE_INACTIVE) {
+ update_group_times(event);
+ event->state = PERF_EVENT_STATE_OFF;
+ }
+}
+
/*
* Disable a event.
*
static void _perf_event_disable(struct perf_event *event)
{
struct perf_event_context *ctx = event->ctx;
- struct task_struct *task = ctx->task;
-
- if (!task) {
- /*
- * Disable the event on the cpu that it's on
- */
- cpu_function_call(event->cpu, __perf_event_disable, event);
- return;
- }
-
-retry:
- if (!task_function_call(task, __perf_event_disable, event))
- return;
raw_spin_lock_irq(&ctx->lock);
- /*
- * If the event is still active, we need to retry the cross-call.
- */
- if (event->state == PERF_EVENT_STATE_ACTIVE) {
+ if (event->state <= PERF_EVENT_STATE_OFF) {
raw_spin_unlock_irq(&ctx->lock);
- /*
- * Reload the task pointer, it might have been changed by
- * a concurrent perf_event_context_sched_out().
- */
- task = ctx->task;
- goto retry;
- }
-
- /*
- * Since we have the lock this context can't be scheduled
- * in, so we can change the state safely.
- */
- if (event->state == PERF_EVENT_STATE_INACTIVE) {
- update_group_times(event);
- event->state = PERF_EVENT_STATE_OFF;
+ return;
}
raw_spin_unlock_irq(&ctx->lock);
+
+ event_function_call(event, __perf_event_disable,
+ ___perf_event_disable, event);
}
/*
ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE, task);
}
+static void ___perf_install_in_context(void *info)
+{
+ struct perf_event *event = info;
+ struct perf_event_context *ctx = event->ctx;
+
+ /*
+ * Since the task isn't running, its safe to add the event, us holding
+ * the ctx->lock ensures the task won't get scheduled in.
+ */
+ add_event_to_ctx(event, ctx);
+}
+
/*
* Cross CPU call to install and enable a performance event
*
struct perf_event *event,
int cpu)
{
- struct task_struct *task = ctx->task;
-
lockdep_assert_held(&ctx->mutex);
event->ctx = ctx;
if (event->cpu != -1)
event->cpu = cpu;
- if (!task) {
- /*
- * Per cpu events are installed via an smp call and
- * the install is always successful.
- */
- cpu_function_call(cpu, __perf_install_in_context, event);
- return;
- }
-
-retry:
- if (!task_function_call(task, __perf_install_in_context, event))
- return;
-
- raw_spin_lock_irq(&ctx->lock);
- /*
- * If we failed to find a running task, but find the context active now
- * that we've acquired the ctx->lock, retry.
- */
- if (ctx->is_active) {
- raw_spin_unlock_irq(&ctx->lock);
- /*
- * Reload the task pointer, it might have been changed by
- * a concurrent perf_event_context_sched_out().
- */
- task = ctx->task;
- goto retry;
- }
-
- /*
- * Since the task isn't running, its safe to add the event, us holding
- * the ctx->lock ensures the task won't get scheduled in.
- */
- add_event_to_ctx(event, ctx);
- raw_spin_unlock_irq(&ctx->lock);
+ event_function_call(event, __perf_install_in_context,
+ ___perf_install_in_context, event);
}
/*
return 0;
}
+void ___perf_event_enable(void *info)
+{
+ __perf_event_mark_enabled((struct perf_event *)info);
+}
+
/*
* Enable a event.
*
static void _perf_event_enable(struct perf_event *event)
{
struct perf_event_context *ctx = event->ctx;
- struct task_struct *task = ctx->task;
- if (!task) {
- /*
- * Enable the event on the cpu that it's on
- */
- cpu_function_call(event->cpu, __perf_event_enable, event);
+ raw_spin_lock_irq(&ctx->lock);
+ if (event->state >= PERF_EVENT_STATE_INACTIVE) {
+ raw_spin_unlock_irq(&ctx->lock);
return;
}
- raw_spin_lock_irq(&ctx->lock);
- if (event->state >= PERF_EVENT_STATE_INACTIVE)
- goto out;
-
/*
* If the event is in error state, clear that first.
- * That way, if we see the event in error state below, we
- * know that it has gone back into error state, as distinct
- * from the task having been scheduled away before the
- * cross-call arrived.
+ *
+ * That way, if we see the event in error state below, we know that it
+ * has gone back into error state, as distinct from the task having
+ * been scheduled away before the cross-call arrived.
*/
if (event->state == PERF_EVENT_STATE_ERROR)
event->state = PERF_EVENT_STATE_OFF;
-
-retry:
- if (!ctx->is_active) {
- __perf_event_mark_enabled(event);
- goto out;
- }
-
raw_spin_unlock_irq(&ctx->lock);
- if (!task_function_call(task, __perf_event_enable, event))
- return;
-
- raw_spin_lock_irq(&ctx->lock);
-
- /*
- * If the context is active and the event is still off,
- * we need to retry the cross-call.
- */
- if (ctx->is_active && event->state == PERF_EVENT_STATE_OFF) {
- /*
- * task could have been flipped by a concurrent
- * perf_event_context_sched_out()
- */
- task = ctx->task;
- goto retry;
- }
-
-out:
- raw_spin_unlock_irq(&ctx->lock);
+ event_function_call(event, __perf_event_enable,
+ ___perf_event_enable, event);
}
/*
* Enable all of a task's events that have been marked enable-on-exec.
* This expects task == current.
*/
-static void perf_event_enable_on_exec(struct perf_event_context *ctx)
+static void perf_event_enable_on_exec(int ctxn)
{
- struct perf_event_context *clone_ctx = NULL;
+ struct perf_event_context *ctx, *clone_ctx = NULL;
struct perf_event *event;
unsigned long flags;
int enabled = 0;
int ret;
local_irq_save(flags);
+ ctx = current->perf_event_ctxp[ctxn];
if (!ctx || !ctx->nr_events)
goto out;
void perf_event_exec(void)
{
- struct perf_event_context *ctx;
int ctxn;
rcu_read_lock();
- for_each_task_context_nr(ctxn) {
- ctx = current->perf_event_ctxp[ctxn];
- if (!ctx)
- continue;
-
- perf_event_enable_on_exec(ctx);
- }
+ for_each_task_context_nr(ctxn)
+ perf_event_enable_on_exec(ctxn);
rcu_read_unlock();
}
u64 value;
};
+static void ___perf_event_period(void *info)
+{
+ struct period_event *pe = info;
+ struct perf_event *event = pe->event;
+ u64 value = pe->value;
+
+ if (event->attr.freq) {
+ event->attr.sample_freq = value;
+ } else {
+ event->attr.sample_period = value;
+ event->hw.sample_period = value;
+ }
+
+ local64_set(&event->hw.period_left, 0);
+}
+
static int __perf_event_period(void *info)
{
struct period_event *pe = info;
static int perf_event_period(struct perf_event *event, u64 __user *arg)
{
struct period_event pe = { .event = event, };
- struct perf_event_context *ctx = event->ctx;
- struct task_struct *task;
u64 value;
if (!is_sampling_event(event))
if (event->attr.freq && value > sysctl_perf_event_sample_rate)
return -EINVAL;
- task = ctx->task;
pe.value = value;
- if (!task) {
- cpu_function_call(event->cpu, __perf_event_period, &pe);
- return 0;
- }
-
-retry:
- if (!task_function_call(task, __perf_event_period, &pe))
- return 0;
-
- raw_spin_lock_irq(&ctx->lock);
- if (ctx->is_active) {
- raw_spin_unlock_irq(&ctx->lock);
- task = ctx->task;
- goto retry;
- }
-
- if (event->attr.freq) {
- event->attr.sample_freq = value;
- } else {
- event->attr.sample_period = value;
- event->hw.sample_period = value;
- }
-
- local64_set(&event->hw.period_left, 0);
- raw_spin_unlock_irq(&ctx->lock);
+ event_function_call(event, __perf_event_period,
+ ___perf_event_period, &pe);
return 0;
}
/* Recursion avoidance in each contexts */
int recursion[PERF_NR_CONTEXTS];
-
- /* Keeps track of cpu being initialized/exited */
- bool online;
};
static DEFINE_PER_CPU(struct swevent_htable, swevent_htable);
hwc->state = !(flags & PERF_EF_START);
head = find_swevent_head(swhash, event);
- if (!head) {
- /*
- * We can race with cpu hotplug code. Do not
- * WARN if the cpu just got unplugged.
- */
- WARN_ON_ONCE(swhash->online);
+ if (WARN_ON_ONCE(!head))
return -EINVAL;
- }
hlist_add_head_rcu(&event->hlist_entry, head);
perf_event_update_userpage(event);
int err = 0;
mutex_lock(&swhash->hlist_mutex);
-
if (!swevent_hlist_deref(swhash) && cpu_online(cpu)) {
struct swevent_hlist *hlist;
struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
mutex_lock(&swhash->hlist_mutex);
- swhash->online = true;
if (swhash->hlist_refcount > 0) {
struct swevent_hlist *hlist;
static void perf_event_exit_cpu(int cpu)
{
- struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
-
perf_event_exit_cpu_context(cpu);
-
- mutex_lock(&swhash->hlist_mutex);
- swhash->online = false;
- swevent_hlist_release(swhash);
- mutex_unlock(&swhash->hlist_mutex);
}
#else
static inline void perf_event_exit_cpu(int cpu) { }
projects / cascardo / linux.git / blobdiff