From 08309379b7083a9ceec0f9bb96a629058fb623c4 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 3 Mar 2011 11:31:20 +0100 Subject: [PATCH] perf: Fix cgroup vs jump_label problem Li Zefan reported that the jump label code sleeps and we're calling it under a spinlock, *fail* ;-) Reported-by: Li Zefan Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/perf_event.c | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 193b1900e64f..ed253aa24ba4 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -820,16 +820,8 @@ list_add_event(struct perf_event *event, struct perf_event_context *ctx) list_add_tail(&event->group_entry, list); } - if (is_cgroup_event(event)) { + if (is_cgroup_event(event)) ctx->nr_cgroups++; - /* - * one more event: - * - that has cgroup constraint on event->cpu - * - that may need work on context switch - */ - atomic_inc(&per_cpu(perf_cgroup_events, event->cpu)); - jump_label_inc(&perf_sched_events); - } list_add_rcu(&event->event_entry, &ctx->event_list); if (!ctx->nr_events) @@ -957,11 +949,8 @@ list_del_event(struct perf_event *event, struct perf_event_context *ctx) event->attach_state &= ~PERF_ATTACH_CONTEXT; - if (is_cgroup_event(event)) { + if (is_cgroup_event(event)) ctx->nr_cgroups--; - atomic_dec(&per_cpu(perf_cgroup_events, event->cpu)); - jump_label_dec(&perf_sched_events); - } ctx->nr_events--; if (event->attr.inherit_stat) @@ -2903,6 +2892,10 @@ static void free_event(struct perf_event *event) atomic_dec(&nr_task_events); if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) put_callchain_buffers(); + if (is_cgroup_event(event)) { + atomic_dec(&per_cpu(perf_cgroup_events, event->cpu)); + jump_label_dec(&perf_sched_events); + } } if (event->buffer) { @@ -6478,6 +6471,13 @@ SYSCALL_DEFINE5(perf_event_open, err = perf_cgroup_connect(pid, event, &attr, group_leader); if (err) goto err_alloc; + /* + * one more event: + * - that has cgroup constraint on event->cpu + * - that may need work on context switch + */ + atomic_inc(&per_cpu(perf_cgroup_events, event->cpu)); + jump_label_inc(&perf_sched_events); } /* -- 2.20.1