Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753502AbaBERT3 (ORCPT ); Wed, 5 Feb 2014 12:19:29 -0500 Received: from mail-oa0-f44.google.com ([209.85.219.44]:46320 "EHLO mail-oa0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752961AbaBERT1 (ORCPT ); Wed, 5 Feb 2014 12:19:27 -0500 MIME-Version: 1.0 In-Reply-To: <1388728091-18564-7-git-send-email-zheng.z.yan@intel.com> References: <1388728091-18564-1-git-send-email-zheng.z.yan@intel.com> <1388728091-18564-7-git-send-email-zheng.z.yan@intel.com> Date: Wed, 5 Feb 2014 18:19:27 +0100 Message-ID: Subject: Re: [PATCH 06/14] perf, core: always switch pmu specific data during context switch From: Stephane Eranian To: "Yan, Zheng" Cc: LKML , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Andi Kleen Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 3, 2014 at 6:48 AM, Yan, Zheng wrote: > 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. > Reviwed-by: Stephane Eranian > Signed-off-by: Yan, Zheng > --- > 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 majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/