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 --- kernel/perf_event.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) Index: linux-2.6/kernel/perf_event.c =================================================================== --- linux-2.6.orig/kernel/perf_event.c +++ linux-2.6/kernel/perf_event.c @@ -2920,12 +2920,6 @@ int perf_event_release_kernel(struct per { 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 per 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); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/