If two tasks were both forked from the same parent task, Events in their perf
task contexts can be the same. Perf core optimizes context switch oout in this
case.
Previous patch inroduces pmu specific data. The data is task specific, so we
should switch the data even when context switch is optimized out.
Signed-off-by: Yan, Zheng <zheng.z....@intel.com>
---
kernel/events/core.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index b6650ab..d6d8dea 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -2319,6 +2319,8 @@ static void perf_event_context_sched_out(struct
task_struct *task, int ctxn,
next->perf_event_ctxp[ctxn] = ctx;
ctx->task = next;
next_ctx->task = task;
+ ctx->task_ctx_data = xchg(&next_ctx->task_ctx_data,
+ ctx->task_ctx_data);
do_switch = 0;
perf_event_sync_stat(ctx, next_ctx);
--
1.8.4.2
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
