diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/events/core.c | 286 |
1 files changed, 109 insertions, 177 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index cfc227ccfceb..bf8244190d0f 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -126,6 +126,37 @@ static int cpu_function_call(int cpu, remote_function_f func, void *info) 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) @@ -1629,6 +1660,17 @@ struct remove_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 * @@ -1656,7 +1698,6 @@ static int __perf_remove_from_context(void *info) return 0; } - /* * Remove the event from a task's (or a CPU's) list of events. * @@ -1673,7 +1714,6 @@ static int __perf_remove_from_context(void *info) 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, @@ -1681,44 +1721,8 @@ static void perf_remove_from_context(struct perf_event *event, bool 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); } /* @@ -1762,6 +1766,20 @@ int __perf_event_disable(void *info) 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. * @@ -1778,43 +1796,16 @@ int __perf_event_disable(void *info) 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); } /* @@ -2067,6 +2058,18 @@ static void perf_event_sched_in(struct perf_cpu_context *cpuctx, 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 * @@ -2143,48 +2146,14 @@ perf_install_in_context(struct perf_event_context *ctx, 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); } /* @@ -2287,6 +2256,11 @@ unlock: return 0; } +void ___perf_event_enable(void *info) +{ + __perf_event_mark_enabled((struct perf_event *)info); +} + /* * Enable a event. * @@ -2299,58 +2273,26 @@ unlock: 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); } /* @@ -4149,6 +4091,22 @@ struct period_event { 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; @@ -4185,8 +4143,6 @@ static int __perf_event_period(void *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)) @@ -4201,34 +4157,10 @@ static int perf_event_period(struct perf_event *event, u64 __user *arg) 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; } |