3.13.11.6 -stable review patch.  If anyone has any objections, please let me 
know.

------------------

From: Jiri Olsa <[email protected]>

commit 1f9a7268c67f0290837aada443d28fd953ddca90 upstream.

The context check in perf_event_context_sched_out allows
non-cloned context to be part of the optimized schedule
out switch.

This could move non-cloned context into another workload
child. Once this child exits, the context is closed and
leaves all original (parent) events in closed state.

Any other new cloned event will have closed state and not
measure anything. And probably causing other odd bugs.

Signed-off-by: Jiri Olsa <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Corey Ashford <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Kamal Mostafa <[email protected]>
---
 kernel/events/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index f0a8ac7..f8519d6 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -2296,7 +2296,7 @@ static void perf_event_context_sched_out(struct 
task_struct *task, int ctxn,
        next_parent = rcu_dereference(next_ctx->parent_ctx);
 
        /* If neither context have a parent context; they cannot be clones. */
-       if (!parent && !next_parent)
+       if (!parent || !next_parent)
                goto unlock;
 
        if (next_parent == ctx || next_ctx == parent || next_parent == parent) {
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to