Re: [PATCH,RFC] perf: panic due to inclied cpu context task_ctxvalue

From: Oleg Nesterov
Date: Sat Mar 26 2011 - 13:18:37 EST


On 03/26, Peter Zijlstra wrote:
>
> diff --git a/kernel/perf_event.c b/kernel/perf_event.c
> index c75925c..e9e4e35 100644
> --- a/kernel/perf_event.c
> +++ b/kernel/perf_event.c
> @@ -1073,6 +1073,8 @@ event_sched_out(struct perf_event *event,
> if (!is_software_event(event))
> cpuctx->active_oncpu--;
> ctx->nr_active--;
> + if (!ctx->nr_active && cpuctx->task_ctx == ctx)
> + cpuctx->task_ctx = NULL;

If we clear cpuctx->task_ctx, we should also clear ctx->is_active.

Otherwise I can't see any problem, but I do not understand this code
enough.

Oleg.

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