Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758956AbZA2PSI (ORCPT ); Thu, 29 Jan 2009 10:18:08 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753117AbZA2PR5 (ORCPT ); Thu, 29 Jan 2009 10:17:57 -0500 Received: from fk-out-0910.google.com ([209.85.128.189]:8061 "EHLO fk-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752779AbZA2PR4 convert rfc822-to-8bit (ORCPT ); Thu, 29 Jan 2009 10:17:56 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=DzBM1Ds4+E2QKvEJ1JNPko4P2oW3Z8VLOT1RwmmtATDrCJ909hzVEqKzS3HWhPdutp ibFudybVC2vPOieYeihOgK2Ro60pxIXI3EC6/5CTljfL7OJBQOqV6zSBAr3AZVYc6jR7 TLfHyWDt5lmMu4wGlw7dgEH2Q4UhnN8vTJHy8= MIME-Version: 1.0 In-Reply-To: <20090129150934.GF6512@elte.hu> References: <497F69A4.2070007@intel.com> <20090127224303.GB5850@nowhere> <20090127225048.GA4652@nowhere> <20090129140451.GM24391@elte.hu> <20090129143120.GS24391@elte.hu> <20090129150934.GF6512@elte.hu> Date: Thu, 29 Jan 2009 16:17:54 +0100 Message-ID: Subject: Re: [PATCH] tracer for sys_open() - sreadahead From: =?ISO-8859-1?Q?Fr=E9d=E9ric_Weisbecker?= To: Ingo Molnar Cc: "Kok, Auke" , Linux Kernel Mailing List , powertop ml , Arjan van de Ven , srostedt@redhat.com, Arnaldo Carvalho de Melo , "Frank Ch. Eigler" , Neil Horman , Ananth N Mavinakayanahalli , utrace-devel@redhat.com, Roland McGrath Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1657 Lines: 44 2009/1/29 Ingo Molnar : > > * Fr?d?ric Weisbecker wrote: > >> 2009/1/29 Ingo Molnar : >> >> >> >> Several people talked me about utrace and gave some examples about it in >> >> this discussion. The Api is very convenient to fetch syscall numbers, >> >> arguments and return values. And the hooks are done in the generic core >> >> code, so it is arch independent. >> >> >> >> The only drawback I can see is that it is not yet merged upstream, in >> >> need of in-kernel users. If it only depends on this condition, we could >> >> be these users... >> >> >> >> What do you think? >> > >> > sure - how do the minimal bits/callbacks look like which enable syscall >> > tracing? >> > >> > Ingo >> >> >> There is a very straightforward example provided by Ananth in there: >> http://lkml.org/lkml/2009/1/28/59 > > I mean, how does the infrastructure patch look like - what code does this > add to the kernel - just to get the syscall tracing bits. Lets get some > progress here - it's clear that tracing syscalls is good, we just need to > do it and look at actual patches. > > Ingo > The latest snapshot version I've found is here: http://people.redhat.com/roland/utrace/2.6-current/utrace.patch This is mostly independent core code and a good number of hooks inside ptrace. But I don't know much about the overhead it potentially brings on ptrace. -- 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/