From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753172AbaIIJyK (ORCPT ); Tue, 9 Sep 2014 05:54:10 -0400 Received: from mga11.intel.com ([192.55.52.93]:49853 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751666AbaIIJyJ (ORCPT ); Tue, 9 Sep 2014 05:54:09 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.04,491,1406617200"; d="scan'208";a="476289832" From: Alexander Shishkin To: Peter Zijlstra Cc: Ingo Molnar , linux-kernel@vger.kernel.org, Robert Richter , Frederic Weisbecker , Mike Galbraith , Paul Mackerras , Stephane Eranian , Andi Kleen , kan.liang@intel.com Subject: Re: [PATCH v4 06/22] perf: Redirect output from inherited events to parents In-Reply-To: <20140908152655.GU19379@twins.programming.kicks-ass.net> References: <1408538179-792-1-git-send-email-alexander.shishkin@linux.intel.com> <1408538179-792-7-git-send-email-alexander.shishkin@linux.intel.com> <20140908152655.GU19379@twins.programming.kicks-ass.net> User-Agent: Notmuch/0.17+49~gaa57e9d (http://notmuchmail.org) Emacs/24.3.1 (x86_64-pc-linux-gnu) Date: Tue, 09 Sep 2014 12:54:04 +0300 Message-ID: <87vboxt8zn.fsf@ashishki-desk.ger.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Peter Zijlstra writes: > On Wed, Aug 20, 2014 at 03:36:03PM +0300, Alexander Shishkin wrote: >> In order to collect AUX data from an inherited event, we can redirect its >> output to parent's ring buffer if possible (they must be cpu affine). This >> patch adds set_output() to the inheritance path. >> >> Signed-off-by: Alexander Shishkin >> --- >> kernel/events/core.c | 6 ++++++ >> 1 file changed, 6 insertions(+) >> >> diff --git a/kernel/events/core.c b/kernel/events/core.c >> index 67f857ab56..e36478564c 100644 >> --- a/kernel/events/core.c >> +++ b/kernel/events/core.c >> @@ -7962,6 +7962,12 @@ inherit_event(struct perf_event *parent_event, >> = parent_event->overflow_handler_context; >> >> /* >> + * Direct child's output to parent's ring buffer (if any) >> + */ >> + if (parent_event->cpu != -1) >> + (void)perf_event_set_output(child_event, parent_event); >> + >> + /* >> * Precalculate sample_data sizes >> */ >> perf_event__header_size(child_event); > > Uhm, nope, see perf_output_begin(), it always redirects output to parent > events. Ouch, indeed. We'll just do the same in perf_aux_output_begin(). Regards, -- Alex