From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756496Ab0KJTQ3 (ORCPT ); Wed, 10 Nov 2010 14:16:29 -0500 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.125]:52091 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756002Ab0KJTQ1 (ORCPT ); Wed, 10 Nov 2010 14:16:27 -0500 X-Authority-Analysis: v=1.1 cv=6ptpMFIBtxRk0xdOb6IhJTbTLVRlKjWFes7R4SsWCrA= c=1 sm=0 a=2Zzf6Ss2cq4A:10 a=Q9fys5e9bTEA:10 a=OPBmh+XkhLl+Enan7BmTLg==:17 a=Mf1wP9fDpHvxvTNziVgA:9 a=iEOQVBC_XbCE7lvVLpu3-w9K0T8A:4 a=PUjeQqilurYA:10 a=OPBmh+XkhLl+Enan7BmTLg==:117 X-Cloudmark-Score: 0 X-Originating-IP: 67.242.120.143 Subject: Re: [RFC/Requirements/Design] h/w error reporting From: Steven Rostedt To: Peter Zijlstra Cc: Ingo Molnar , "Luck, Tony" , linux-kernel@vger.kernel.org, ying.huang@intel.com, bp@alien8.de, tglx@linutronix.de, akpm@linux-foundation.org, mchehab@redhat.com, =?ISO-8859-1?Q?Fr=E9d=E9ric?= Weisbecker , Arnaldo Carvalho de Melo , Arjan van de Ven , Mathieu Desnoyers In-Reply-To: <1289413460.2084.27.camel@laptop> References: <4cd9edd7543527b78@agluck-desktop.sc.intel.com> <20101110101450.GA18481@elte.hu> <1289400056.12418.139.camel@gandalf.stny.rr.com> <1289400234.2191.129.camel@laptop> <1289401781.12418.145.camel@gandalf.stny.rr.com> <1289403019.2084.17.camel@laptop> <20101110174852.GB4001@elte.hu> <1289412329.12418.177.camel@gandalf.stny.rr.com> <1289413460.2084.27.camel@laptop> Content-Type: text/plain; charset="ISO-8859-15" Date: Wed, 10 Nov 2010 14:16:24 -0500 Message-ID: <1289416584.12418.184.camel@gandalf.stny.rr.com> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2010-11-10 at 19:24 +0100, Peter Zijlstra wrote: > On Wed, 2010-11-10 at 13:05 -0500, Steven Rostedt wrote: > > > > Peter said at LPC that the perf buffering system was not designed to > > handle high speed tracing. But he also said he does not like the way the > > ftrace buffering works. > > You're not very good at listening, Or I'm not good at rephrasing, but both are probably true ;-) > I said the perf infrastructure and > event handling mechanism isn't geared towards full throughput but > instead on sampling. OK, not the buffering, but the infrastructure. That's not much of a difference to this topic. Which is about the ABI which includes all from the user to the buffer. > > There is lots of code between getting the event and landing it in the > buffer. The buffer itself is perfectly suited for high speed low > overhead stuffs, the perf data format possibly not because its not > bitfield happy. Well, we need to separate out the buffer in perf regardless, since it is very entwined in the code. Does it now support flight recorder mode? -- Steve