Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751173AbbKYJoe (ORCPT ); Wed, 25 Nov 2015 04:44:34 -0500 Received: from szxga01-in.huawei.com ([58.251.152.64]:49512 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750726AbbKYJoc (ORCPT ); Wed, 25 Nov 2015 04:44:32 -0500 Message-ID: <565582E0.7070202@huawei.com> Date: Wed, 25 Nov 2015 17:44:00 +0800 From: "Wangnan (F)" User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: Peter Zijlstra , Yunlong Song CC: , , , , , , , , , , , , , , , Subject: Re: [PATCH] perf record: Add snapshot mode support for perf's regular events References: <1448373632-8806-1-git-send-email-yunlong.song@huawei.com> <20151125092728.GZ17308@twins.programming.kicks-ass.net> In-Reply-To: <20151125092728.GZ17308@twins.programming.kicks-ass.net> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.111.66.109] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A090204.565582F1.0017,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: eecc8d3f4324afdf4aa3b94fd1c059b8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1035 Lines: 24 On 2015/11/25 17:27, Peter Zijlstra wrote: > On Tue, Nov 24, 2015 at 10:00:31PM +0800, Yunlong Song wrote: >> In our patch, we create and maintain a user space ring buffer to store >> perf's tracing info, instead of directly writing to perf.data file as >> before. In snapshot mode, only a SIGUSR2 signal can trigger perf to dump >> the tracing info currently stored in the user space ring buffer to >> perf.data file. > I would very much like to first fix the perf overwrite mode: see > lkml.kernel.org/r/20151023151205.GW11639@twins.programming.kicks-ass.net I think they can be done in parallel. We can first do something with tracking events and perf's output file, and wait for kernel level overwrite mode fixed, then decide whether to implement perf's own ringbuffer. Thank you. -- 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/