From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759202AbZDFVVX (ORCPT ); Mon, 6 Apr 2009 17:21:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755674AbZDFVVN (ORCPT ); Mon, 6 Apr 2009 17:21:13 -0400 Received: from casper.infradead.org ([85.118.1.10]:40063 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753972AbZDFVVM (ORCPT ); Mon, 6 Apr 2009 17:21:12 -0400 Subject: Re: [PATCH 5/6] perf_counter: add more context information From: Peter Zijlstra To: Corey Ashford Cc: Ingo Molnar , Paul Mackerras , linux-kernel@vger.kernel.org In-Reply-To: <49DA70F0.3020108@linux.vnet.ibm.com> References: <20090402091158.291810516@chello.nl> <20090402091319.493101305@chello.nl> <1238763023.798.27.camel@twins> <49D654AB.4030207@linux.vnet.ibm.com> <1239015668.798.4243.camel@twins> <1239016035.798.4254.camel@twins> <49DA4FA0.6090902@linux.vnet.ibm.com> <1239044818.798.4775.camel@twins> <49DA6324.9080801@linux.vnet.ibm.com> <1239050799.4557.24.camel@laptop> <49DA70F0.3020108@linux.vnet.ibm.com> Content-Type: text/plain Date: Mon, 06 Apr 2009 23:21:04 +0200 Message-Id: <1239052864.4557.62.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.26.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2009-04-06 at 14:15 -0700, Corey Ashford wrote: > > Peter Zijlstra wrote: > > On Mon, 2009-04-06 at 13:16 -0700, Corey Ashford wrote: > > > >>>> One downside of this approach is that you if you specify "no header" > >>>> (currently not possible, but maybe later?), you will not be able to get > >>>> the level bits. > >>> Would this be desirable? > > > >> I think it would. For one use case I'm working on right now, simple > >> profiling, all I need are ip's. If I could omit the header, that would > >> reduce the frequency of sigio's by a factor of three, and make it faster > >> to read up the ip's when the SIGIO's occur. > > > > Self-profiling? > > > > So you're interested in getting the smallest possible record size, that > > would still be 2 u64, right? Otherwise you don't get the IP context that > > started this. > > > > > > Self-profiling mainly, yes. PAPI specs an ability for remote monitoring > of processes and threads, but I think it's only partially implemented. > > So when you are talking about IP context, you mean pid/tid? Ah, we called it level before, the hv/kernel/user thing. For remote profiling you'd want to have the mmap thing too.