From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751852AbaEGVIq (ORCPT ); Wed, 7 May 2014 17:08:46 -0400 Received: from mga03.intel.com ([143.182.124.21]:14855 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750786AbaEGVIp (ORCPT ); Wed, 7 May 2014 17:08:45 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,1006,1389772800"; d="scan'208";a="429098887" Date: Wed, 7 May 2014 14:08:43 -0700 From: Andi Kleen To: Peter Zijlstra Cc: Alexander Shishkin , Ingo Molnar , linux-kernel@vger.kernel.org, Frederic Weisbecker , Mike Galbraith , Paul Mackerras , Stephane Eranian , Adrian Hunter , Matt Fleming Subject: Re: [PATCH v1 03/11] perf: Allow for multiple ring buffers per event Message-ID: <20140507210843.GS19657@tassilo.jf.intel.com> References: <1391683834-29868-1-git-send-email-alexander.shishkin@linux.intel.com> <1391683834-29868-4-git-send-email-alexander.shishkin@linux.intel.com> <20140507152640.GR30445@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140507152640.GR30445@twins.programming.kicks-ass.net> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Then, when data inside that aux data store changes they should inject an > PERF_RECORD_AUX to indicate this did happen, which ties it back into the > normal event flow. What happens when the aux buffer wraps? How would the client know if the data belongs to this _AUX entry or some later one? May need some extra sequence numbers in the mmap header and the aux entry to handle this. -Andi