diff options
Diffstat (limited to 'kernel/perf_event.c')
| -rw-r--r-- | kernel/perf_event.c | 96 |
1 files changed, 64 insertions, 32 deletions
diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 9dbe8cdaf145..a4fa381db3c2 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -83,14 +83,6 @@ extern __weak const struct pmu *hw_perf_event_init(struct perf_event *event) void __weak hw_perf_disable(void) { barrier(); } void __weak hw_perf_enable(void) { barrier(); } -int __weak -hw_perf_group_sched_in(struct perf_event *group_leader, - struct perf_cpu_context *cpuctx, - struct perf_event_context *ctx) -{ - return 0; -} - void __weak perf_event_print_debug(void) { } static DEFINE_PER_CPU(int, perf_disable_count); @@ -263,6 +255,18 @@ static void update_event_times(struct perf_event *event) event->total_time_running = run_end - event->tstamp_running; } +/* + * Update total_time_enabled and total_time_running for all events in a group. + */ +static void update_group_times(struct perf_event *leader) +{ + struct perf_event *event; + + update_event_times(leader); + list_for_each_entry(event, &leader->sibling_list, group_entry) + update_event_times(event); +} + static struct list_head * ctx_group_list(struct perf_event *event, struct perf_event_context *ctx) { @@ -316,8 +320,6 @@ list_add_event(struct perf_event *event, struct perf_event_context *ctx) static void list_del_event(struct perf_event *event, struct perf_event_context *ctx) { - struct perf_event *sibling, *tmp; - if (list_empty(&event->group_entry)) return; ctx->nr_events--; @@ -330,7 +332,7 @@ list_del_event(struct perf_event *event, struct perf_event_context *ctx) if (event->group_leader != event) event->group_leader->nr_siblings--; - update_event_times(event); + update_group_times(event); /* * If event was in error state, then keep it @@ -341,6 +343,12 @@ list_del_event(struct perf_event *event, struct perf_event_context *ctx) */ if (event->state > PERF_EVENT_STATE_OFF) event->state = PERF_EVENT_STATE_OFF; +} + +static void +perf_destroy_group(struct perf_event *event, struct perf_event_context *ctx) +{ + struct perf_event *sibling, *tmp; /* * If this was a group event with sibling events then @@ -506,18 +514,6 @@ retry: } /* - * Update total_time_enabled and total_time_running for all events in a group. - */ -static void update_group_times(struct perf_event *leader) -{ - struct perf_event *event; - - update_event_times(leader); - list_for_each_entry(event, &leader->sibling_list, group_entry) - update_event_times(event); -} - -/* * Cross CPU call to disable a performance event */ static void __perf_event_disable(void *info) @@ -641,15 +637,20 @@ group_sched_in(struct perf_event *group_event, struct perf_cpu_context *cpuctx, struct perf_event_context *ctx) { - struct perf_event *event, *partial_group; + struct perf_event *event, *partial_group = NULL; + const struct pmu *pmu = group_event->pmu; + bool txn = false; int ret; if (group_event->state == PERF_EVENT_STATE_OFF) return 0; - ret = hw_perf_group_sched_in(group_event, cpuctx, ctx); - if (ret) - return ret < 0 ? ret : 0; + /* Check if group transaction availabe */ + if (pmu->start_txn) + txn = true; + + if (txn) + pmu->start_txn(pmu); if (event_sched_in(group_event, cpuctx, ctx)) return -EAGAIN; @@ -664,9 +665,19 @@ group_sched_in(struct perf_event *group_event, } } - return 0; + if (!txn) + return 0; + + ret = pmu->commit_txn(pmu); + if (!ret) { + pmu->cancel_txn(pmu); + return 0; + } group_error: + if (txn) + pmu->cancel_txn(pmu); + /* * Groups can be scheduled in as one unit only, so undo any * partial group before returning: @@ -1861,9 +1872,30 @@ int perf_event_release_kernel(struct perf_event *event) { struct perf_event_context *ctx = event->ctx; + /* + * Remove from the PMU, can't get re-enabled since we got + * here because the last ref went. + */ + perf_event_disable(event); + WARN_ON_ONCE(ctx->parent_ctx); - mutex_lock(&ctx->mutex); - perf_event_remove_from_context(event); + /* + * There are two ways this annotation is useful: + * + * 1) there is a lock recursion from perf_event_exit_task + * see the comment there. + * + * 2) there is a lock-inversion with mmap_sem through + * perf_event_read_group(), which takes faults while + * holding ctx->mutex, however this is called after + * the last filedesc died, so there is no possibility + * to trigger the AB-BA case. + */ + mutex_lock_nested(&ctx->mutex, SINGLE_DEPTH_NESTING); + raw_spin_lock_irq(&ctx->lock); + list_del_event(event, ctx); + perf_destroy_group(event, ctx); + raw_spin_unlock_irq(&ctx->lock); mutex_unlock(&ctx->mutex); mutex_lock(&event->owner->perf_event_mutex); @@ -5021,7 +5053,7 @@ err_fput_free_put_context: err_free_put_context: if (err < 0) - kfree(event); + free_event(event); err_put_context: if (err < 0) @@ -5300,7 +5332,7 @@ void perf_event_exit_task(struct task_struct *child) * * But since its the parent context it won't be the same instance. */ - mutex_lock_nested(&child_ctx->mutex, SINGLE_DEPTH_NESTING); + mutex_lock(&child_ctx->mutex); again: list_for_each_entry_safe(child_event, tmp, &child_ctx->pinned_groups, |