Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757317AbYJVRZr (ORCPT ); Wed, 22 Oct 2008 13:25:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753129AbYJVRZg (ORCPT ); Wed, 22 Oct 2008 13:25:36 -0400 Received: from gv-out-0910.google.com ([216.239.58.191]:19171 "EHLO gv-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753133AbYJVRZg (ORCPT ); Wed, 22 Oct 2008 13:25:36 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; b=gOgC0iwN4VB5Sqaj3SJbl+rHd/HNQ4SPTxWi7LnwgiiHZM4Zq+d1nyMTwB2IZ9p4jv RmIiZfkLV9mXd25AaS9ykW7SMI0AGUZohFMeaWpyzwK3KslggrL4yJGvX8v8758c3fe8 dcWWz+LT51vx2l10c/IPfAqJ4XrJyHrcQnYYM= Message-ID: <48FF620A.9040506@gmail.com> Date: Wed, 22 Oct 2008 20:25:30 +0300 From: =?UTF-8?B?VMO2csO2ayBFZHdpbg==?= User-Agent: Mozilla-Thunderbird 2.0.0.17 (X11/20081018) MIME-Version: 1.0 To: Peter Zijlstra CC: Ingo Molnar , sandmann@daimi.au.dk, linux-kernel@vger.kernel.org, Steven Rostedt , Arjan van de Ven Subject: Re: [PATCH 4/4] Implement semaphore latency tracer References: <1223817124-27239-1-git-send-email-edwintorok@gmail.com> <1223817124-27239-6-git-send-email-edwintorok@gmail.com> <1223838786.8634.8.camel@lappy.programming.kicks-ass.net> <48F259A7.2030800@gmail.com> <20081022152842.GI23060@elte.hu> <48FF49BD.8000608@gmail.com> <20081022154851.GL23060@elte.hu> <1224696137.20069.6.camel@twins> In-Reply-To: <1224696137.20069.6.camel@twins> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1824 Lines: 47 On 2008-10-22 20:22, Peter Zijlstra wrote: > On Wed, 2008-10-22 at 17:48 +0200, Ingo Molnar wrote: > >> * Török Edwin wrote: >> >> >>> On 2008-10-22 18:28, Ingo Molnar wrote: >>> >>>> hm, but the most common synchronization primitive are mutexes - and >>>> those are not covered by your patchset. >>>> >>>> >>> Indeed. I've seen a patch from Jason Baron to introduce tracepoints >>> for mutexes, but the conclusion was that the tracepoints should be in >>> lockstat instead. >>> >>> And if lockstat is enabled Peter Zijlstra's 'contend with points' >>> patch seems to do exactly what I want to. >>> >>> However I think it would be useful to have (a tracepoints based?) >>> latency tracker, which can be enabled/disabled at runtime, and which >>> doesn't add any data to the mutex/semaphore structures. My patchset >>> was a first attempt towards that, but it seems that such use of >>> tracepoints is not welcome at this time? >>> >>> Please tell me if I should continue working on this, or if I my >>> patches are designed totally on the wrong way. >>> >> i think if you hook into Peter's lockstat APIs that should give us a >> pretty good tracer, with no ugliness introduced. That would be rather >> interesting. Peter, do you concur? >> > > Yes, I've already suggested this. Use the exact same hooks that > lockdep/lockstat use. Ok, I'll work on this when I get some time :) [hopefully this weekend test the 'contend with points patch', next weekend write the new tracepoints] Best regards, --Edwin -- 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/