Messages in this thread Patch in this message | | | From | Kan Liang <> | Subject | [PATCH V8 06/14] perf, core: always switch pmu specific data during context switch | Date | Thu, 6 Nov 2014 09:54:23 -0500 |
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From: Yan, Zheng <zheng.z.yan@intel.com>
If two tasks were both forked from the same parent task, Events in their perf task contexts can be the same. Perf core may leave out switching the perf event contexts.
Previous patch inroduces pmu specific data. The data is for saving the LBR stack, it is task specific. So we need to switch the data even when context switch is optimized out.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com> Signed-off-by: Kan Liang <kan.liang@intel.com> --- kernel/events/core.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/kernel/events/core.c b/kernel/events/core.c index 08d6671..4360c95 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -2420,6 +2420,9 @@ 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; + + swap(ctx->task_ctx_data, next_ctx->task_ctx_data); + do_switch = 0; perf_event_sync_stat(ctx, next_ctx); -- 1.8.3.2
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