Merge commit 'v2.6.39-rc4' into sched/core

Merge reason: Pick up upstream fixes.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 12 insertions, 0 deletions

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 27960f114efd..8e81a9860a0d 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -364,6 +364,7 @@ void perf_cgroup_switch(struct task_struct *task, int mode)
                         }
 
                         if (mode & PERF_CGROUP_SWIN) {
+                                WARN_ON_ONCE(cpuctx->cgrp);
                                 /* set cgrp before ctxsw in to
                                  * allow event_filter_match() to not
                                  * have to pass task around
@@ -2423,6 +2424,14 @@ static void perf_event_enable_on_exec(struct perf_event_context *ctx)
         if (!ctx || !ctx->nr_events)
                 goto out;
 
+        /*
+         * We must ctxsw out cgroup events to avoid conflict
+         * when invoking perf_task_event_sched_in() later on
+         * in this function. Otherwise we end up trying to
+         * ctxswin cgroup events which are already scheduled
+         * in.
+         */
+        perf_cgroup_sched_out(current);
         task_ctx_sched_out(ctx, EVENT_ALL);
 
         raw_spin_lock(&ctx->lock);
@@ -2447,6 +2456,9 @@ static void perf_event_enable_on_exec(struct perf_event_context *ctx)
 
         raw_spin_unlock(&ctx->lock);
 
+        /*
+         * Also calls ctxswin for cgroup events, if any:
+         */
         perf_event_context_sched_in(ctx, ctx->task);
 out:
         local_irq_restore(flags);