diff options
Diffstat (limited to 'kernel/events')
| -rw-r--r-- | kernel/events/core.c | 89 | ||||
| -rw-r--r-- | kernel/events/ring_buffer.c | 37 |
2 files changed, 81 insertions, 45 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 72d06e302e99..dc7dead2d2cc 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -2009,8 +2009,8 @@ event_sched_out(struct perf_event *event, event->pmu->del(event, 0); event->oncpu = -1; - if (event->pending_disable) { - event->pending_disable = 0; + if (READ_ONCE(event->pending_disable) >= 0) { + WRITE_ONCE(event->pending_disable, -1); state = PERF_EVENT_STATE_OFF; } perf_event_set_state(event, state); @@ -2198,7 +2198,8 @@ EXPORT_SYMBOL_GPL(perf_event_disable); void perf_event_disable_inatomic(struct perf_event *event) { - event->pending_disable = 1; + WRITE_ONCE(event->pending_disable, smp_processor_id()); + /* can fail, see perf_pending_event_disable() */ irq_work_queue(&event->pending); } @@ -5810,10 +5811,45 @@ void perf_event_wakeup(struct perf_event *event) } } +static void perf_pending_event_disable(struct perf_event *event) +{ + int cpu = READ_ONCE(event->pending_disable); + + if (cpu < 0) + return; + + if (cpu == smp_processor_id()) { + WRITE_ONCE(event->pending_disable, -1); + perf_event_disable_local(event); + return; + } + + /* + * CPU-A CPU-B + * + * perf_event_disable_inatomic() + * @pending_disable = CPU-A; + * irq_work_queue(); + * + * sched-out + * @pending_disable = -1; + * + * sched-in + * perf_event_disable_inatomic() + * @pending_disable = CPU-B; + * irq_work_queue(); // FAILS + * + * irq_work_run() + * perf_pending_event() + * + * But the event runs on CPU-B and wants disabling there. + */ + irq_work_queue_on(&event->pending, cpu); +} + static void perf_pending_event(struct irq_work *entry) { - struct perf_event *event = container_of(entry, - struct perf_event, pending); + struct perf_event *event = container_of(entry, struct perf_event, pending); int rctx; rctx = perf_swevent_get_recursion_context(); @@ -5822,10 +5858,7 @@ static void perf_pending_event(struct irq_work *entry) * and we won't recurse 'further'. */ - if (event->pending_disable) { - event->pending_disable = 0; - perf_event_disable_local(event); - } + perf_pending_event_disable(event); if (event->pending_wakeup) { event->pending_wakeup = 0; @@ -9044,26 +9077,29 @@ static void perf_event_addr_filters_apply(struct perf_event *event) if (task == TASK_TOMBSTONE) return; - if (!ifh->nr_file_filters) - return; - - mm = get_task_mm(event->ctx->task); - if (!mm) - goto restart; + if (ifh->nr_file_filters) { + mm = get_task_mm(event->ctx->task); + if (!mm) + goto restart; - down_read(&mm->mmap_sem); + down_read(&mm->mmap_sem); + } raw_spin_lock_irqsave(&ifh->lock, flags); list_for_each_entry(filter, &ifh->list, entry) { - event->addr_filter_ranges[count].start = 0; - event->addr_filter_ranges[count].size = 0; + if (filter->path.dentry) { + /* + * Adjust base offset if the filter is associated to a + * binary that needs to be mapped: + */ + event->addr_filter_ranges[count].start = 0; + event->addr_filter_ranges[count].size = 0; - /* - * Adjust base offset if the filter is associated to a binary - * that needs to be mapped: - */ - if (filter->path.dentry) perf_addr_filter_apply(filter, mm, &event->addr_filter_ranges[count]); + } else { + event->addr_filter_ranges[count].start = filter->offset; + event->addr_filter_ranges[count].size = filter->size; + } count++; } @@ -9071,9 +9107,11 @@ static void perf_event_addr_filters_apply(struct perf_event *event) event->addr_filters_gen++; raw_spin_unlock_irqrestore(&ifh->lock, flags); - up_read(&mm->mmap_sem); + if (ifh->nr_file_filters) { + up_read(&mm->mmap_sem); - mmput(mm); + mmput(mm); + } restart: perf_event_stop(event, 1); @@ -10236,6 +10274,7 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu, init_waitqueue_head(&event->waitq); + event->pending_disable = -1; init_irq_work(&event->pending, perf_pending_event); mutex_init(&event->mmap_mutex); diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c index a4047321d7d8..5eedb49a65ea 100644 --- a/kernel/events/ring_buffer.c +++ b/kernel/events/ring_buffer.c @@ -392,7 +392,7 @@ void *perf_aux_output_begin(struct perf_output_handle *handle, * store that will be enabled on successful return */ if (!handle->size) { /* A, matches D */ - event->pending_disable = 1; + event->pending_disable = smp_processor_id(); perf_output_wakeup(handle); local_set(&rb->aux_nest, 0); goto err_put; @@ -455,24 +455,21 @@ void perf_aux_output_end(struct perf_output_handle *handle, unsigned long size) rb->aux_head += size; } - if (size || handle->aux_flags) { - /* - * Only send RECORD_AUX if we have something useful to communicate - * - * Note: the OVERWRITE records by themselves are not considered - * useful, as they don't communicate any *new* information, - * aside from the short-lived offset, that becomes history at - * the next event sched-in and therefore isn't useful. - * The userspace that needs to copy out AUX data in overwrite - * mode should know to use user_page::aux_head for the actual - * offset. So, from now on we don't output AUX records that - * have *only* OVERWRITE flag set. - */ - - if (handle->aux_flags & ~(u64)PERF_AUX_FLAG_OVERWRITE) - perf_event_aux_event(handle->event, aux_head, size, - handle->aux_flags); - } + /* + * Only send RECORD_AUX if we have something useful to communicate + * + * Note: the OVERWRITE records by themselves are not considered + * useful, as they don't communicate any *new* information, + * aside from the short-lived offset, that becomes history at + * the next event sched-in and therefore isn't useful. + * The userspace that needs to copy out AUX data in overwrite + * mode should know to use user_page::aux_head for the actual + * offset. So, from now on we don't output AUX records that + * have *only* OVERWRITE flag set. + */ + if (size || (handle->aux_flags & ~(u64)PERF_AUX_FLAG_OVERWRITE)) + perf_event_aux_event(handle->event, aux_head, size, + handle->aux_flags); rb->user_page->aux_head = rb->aux_head; if (rb_need_aux_wakeup(rb)) @@ -480,7 +477,7 @@ void perf_aux_output_end(struct perf_output_handle *handle, unsigned long size) if (wakeup) { if (handle->aux_flags & PERF_AUX_FLAG_TRUNCATED) - handle->event->pending_disable = 1; + handle->event->pending_disable = smp_processor_id(); perf_output_wakeup(handle); } |