From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755055AbZBCNdS (ORCPT ); Tue, 3 Feb 2009 08:33:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752475AbZBCNdI (ORCPT ); Tue, 3 Feb 2009 08:33:08 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:59565 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752311AbZBCNdF (ORCPT ); Tue, 3 Feb 2009 08:33:05 -0500 Date: Tue, 3 Feb 2009 14:32:51 +0100 From: Ingo Molnar To: Pavel Machek Cc: "Kok, Auke" , Linux Kernel Mailing List , powertop ml , Arjan van de Ven , srostedt@redhat.com Subject: Re: [PATCH] tracer for sys_open() - sreadahead Message-ID: <20090203133251.GD29046@elte.hu> References: <497F69A4.2070007@intel.com> <20090130202219.GA1253@ucw.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090130202219.GA1253@ucw.cz> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Pavel Machek wrote: > On Tue 2009-01-27 12:08:04, Kok, Auke wrote: > > > > This tracer monitors regular file open() syscalls. This is a fast > > and low-overhead alternative to strace, and does not allow or > > require to be attached to every process. > > > > The tracer only logs succesfull calls, as those are the only ones we > > are currently interested in, and we can determine the absolute path > > of these files as we log. > > Maybe fanotify() should be used instead? > > Or maybe just plain strace? One slow boot should not really hurt... ptrace is out of question for good tracing because it's not a transparent probe. (ptrace monopolizes the traced task - if we use that then we break regular strace usage.) Ingo