Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758225AbZA2Osz (ORCPT ); Thu, 29 Jan 2009 09:48:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753880AbZA2Osp (ORCPT ); Thu, 29 Jan 2009 09:48:45 -0500 Received: from fk-out-0910.google.com ([209.85.128.191]:5178 "EHLO fk-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753779AbZA2Oso convert rfc822-to-8bit (ORCPT ); Thu, 29 Jan 2009 09:48:44 -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=QnsrUH/gN3bbTvyoGyHndb274Km22s9z4Vb8HhKhrsgL2kN3WnGQ/EGQ6oMXF0C3x2 SbzHj6hvTQb3JXs0wadYoUa31+FvyYzLG9e9LIPf7qEa5GGrk2us+ORDfd8gQEny+EbB slGu/8egag9CUmsYIyw/1TiRQzQGmo4WX+Qd0= MIME-Version: 1.0 In-Reply-To: References: <497F69A4.2070007@intel.com> <20090127224303.GB5850@nowhere> <20090127225048.GA4652@nowhere> <20090129140451.GM24391@elte.hu> <20090129143120.GS24391@elte.hu> Date: Thu, 29 Jan 2009 15:48:41 +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: 1316 Lines: 35 2009/1/29 Fr?d?ric Weisbecker : > 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 > One other drawback may be the fact that utrace will be traced by the function tracers... adding some junk on their traces. But I guess this is just a matter of some patches to make it not traced. BTW, there is an interesting proof of concept there: http://lkml.org/lkml/2009/1/27/294 -- 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/