From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754159AbaCNKjc (ORCPT ); Fri, 14 Mar 2014 06:39:32 -0400 Received: from merlin.infradead.org ([205.233.59.134]:38164 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753162AbaCNKjb (ORCPT ); Fri, 14 Mar 2014 06:39:31 -0400 Date: Fri, 14 Mar 2014 11:38:32 +0100 From: Peter Zijlstra To: Andi Kleen 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: <20140314103832.GQ27965@twins.programming.kicks-ass.net> References: <1391683834-29868-1-git-send-email-alexander.shishkin@linux.intel.com> <1391683834-29868-4-git-send-email-alexander.shishkin@linux.intel.com> <20140217143340.GR27965@twins.programming.kicks-ass.net> <20140218023659.GV12219@tassilo.jf.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140218023659.GV12219@tassilo.jf.intel.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 17, 2014 at 06:36:59PM -0800, Andi Kleen wrote: > > I'm not convinced it needs to be a PERF_RECORD_SAMPLE; but some > > PERF_RECORD_* type for sure. > > Adding a header shouldn't be a problem, it's merely wasting 4K. > > > Also it must allow interleaving with other > events. > > But can you describe a concrete use case where interleaving is better? I really don't want the multi-buffer nonsense proposed. An event gets _1_ buffer, that's it. That also means that if someone redirect another event into this buffer, it needs to just work. And because its a perf buffer, people expect it to look like one. So we've got 'wrap' it.