Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753480AbYL0LWH (ORCPT ); Sat, 27 Dec 2008 06:22:07 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753547AbYL0LVk (ORCPT ); Sat, 27 Dec 2008 06:21:40 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:37806 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753325AbYL0LVi (ORCPT ); Sat, 27 Dec 2008 06:21:38 -0500 Date: Sat, 27 Dec 2008 12:20:55 +0100 From: Ingo Molnar To: Vladislav Bolkhovitin Cc: =?iso-8859-1?Q?Fr=E9d=E9ric?= Weisbecker , Steven Rostedt , Sam Ravnborg , linux-scsi@vger.kernel.org, James Bottomley , Andrew Morton , FUJITA Tomonori , Mike Christie , Jeff Garzik , Boaz Harrosh , Linus Torvalds , linux-kernel@vger.kernel.org, scst-devel@lists.sourceforge.net, Bart Van Assche , "Nicholas A. Bellinger" Subject: Re: [PATCH][RFC 2/23]: SCST core Message-ID: <20081227112055.GB18819@elte.hu> References: <20081210191213.GA15273@uranus.ravnborg.org> <49414DBE.6070801@vlnb.net> <20081211210917.GB27010@uranus.ravnborg.org> <4942BA85.3070408@vlnb.net> <1229118607.24995.18.camel@localhost.localdomain> <4943CAAB.4050008@vlnb.net> <494A37E9.5000009@vlnb.net> <495137F4.9010404@vlnb.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <495137F4.9010404@vlnb.net> 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 Content-Length: 3280 Lines: 77 * Vladislav Bolkhovitin wrote: >> The word graph is actually here to explain here that we not only trace >> each function call but we can actually retrieve all of the call path of >> a function and then draw it as if it was C code: >> >> 0) ! 108.528 us | } >> 0) | irq_exit() { >> 0) | do_softirq() { >> 0) | __do_softirq() { >> 0) 0.895 us | __local_bh_disable(); >> 0) | run_timer_softirq() { >> 0) 0.827 us | hrtimer_run_pending(); >> 0) 1.226 us | _spin_lock_irq(); >> 0) | _spin_unlock_irq() { >> 0) 6.550 us | } >> 0) 0.924 us | _local_bh_enable(); >> 0) + 12.129 us | } >> 0) + 13.911 us | } >> 0) 0.707 us | idle_cpu(); >> 0) + 17.009 us | } >> 0) ! 137.419 us | } >> 0) <========== | >> 0) 1.045 us | } >> 0) ! 148.908 us | } >> 0) ! 151.022 us | } >> 0) ! 153.022 us | } >> 0) 0.963 us | journal_mark_dirty(); >> 0) 0.925 us | __brelse(); > > Unfortunately, it lacks very useful "TASK-PID, CPU#, TIMESTAMP" header > fields.. those obscure readability in the typical usecases, but you can get them anytime via using this existing trace_options runtime switch: echo funcgraph-proc > /debug/tracing/trace_options resulting in traces like this: # CPU TASK/PID OVERHEAD/DURATION FUNCTION CALLS # | | | | | | | | ------------------------------------------ 0) distccd-28400 => cc1-30212 ------------------------------------------ 0) cc1-30212 | 0.270 us | } 0) cc1-30212 | | __do_fault() { 0) cc1-30212 | | filemap_fault() { 0) cc1-30212 | | find_lock_page() { 0) cc1-30212 | 0.453 us | find_get_page(); 0) cc1-30212 | 0.997 us | } 0) cc1-30212 | | PageUptodate() { 0) cc1-30212 | 0.266 us | constant_test_bit(); 0) cc1-30212 | 0.799 us | } 0) cc1-30212 | 0.379 us | mark_page_accessed(); 0) cc1-30212 | 3.275 us | } 0) cc1-30212 | 0.276 us | _spin_lock(); 0) cc1-30212 | 0.389 us | page_add_file_rmap(); 0) cc1-30212 | | unlock_page() { 0) cc1-30212 | 0.266 us | page_waitqueue(); 0) cc1-30212 | 0.381 us | __wake_up_bit(); 0) cc1-30212 | 1.442 us | } 0) cc1-30212 | 6.897 us | } 0) cc1-30212 |+ 11.663 us | } 0) cc1-30212 | | up_read() { 0) cc1-30212 | 0.280 us | _spin_lock_irqsave(); Thanks, Ingo -- 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/