From: Peter Zijlstra Date: Sat, 9 Apr 2011 19:17:47 +0000 (+0200) Subject: perf: Change close() semantics for group events X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=e03a9a55b4e;p=linux-beck.git perf: Change close() semantics for group events In order to always call list_del_event() on the correct cpu if the event is part of an active context and avoid having to do two IPIs, change the close() semantics slightly. The current perf_event_disable() call would disable a whole group if the event that's being closed is the group leader, whereas the new code keeps the group siblings enabled. People should not rely on this behaviour and I don't think they do, but in case we find they do, the fix is easy and we have to take the double IPI cost. Signed-off-by: Peter Zijlstra Cc: Vince Weaver Link: http://lkml.kernel.org/r/20110409192142.038377551@chello.nl Signed-off-by: Ingo Molnar --- diff --git a/kernel/events/core.c b/kernel/events/core.c index 802f3b24eeef..c378062da277 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -2920,12 +2920,6 @@ 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); /* * There are two ways this annotation is useful: @@ -2942,8 +2936,8 @@ int perf_event_release_kernel(struct perf_event *event) mutex_lock_nested(&ctx->mutex, SINGLE_DEPTH_NESTING); raw_spin_lock_irq(&ctx->lock); perf_group_detach(event); - list_del_event(event, ctx); raw_spin_unlock_irq(&ctx->lock); + perf_remove_from_context(event); mutex_unlock(&ctx->mutex); free_event(event);