Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S269752AbUJMQx5 (ORCPT ); Wed, 13 Oct 2004 12:53:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S269753AbUJMQx4 (ORCPT ); Wed, 13 Oct 2004 12:53:56 -0400 Received: from viper.oldcity.dca.net ([216.158.38.4]:23250 "HELO viper.oldcity.dca.net") by vger.kernel.org with SMTP id S269752AbUJMQxq (ORCPT ); Wed, 13 Oct 2004 12:53:46 -0400 Subject: Re: [patch] voluntary-preempt-2.6.9-rc3-mm3-T3 From: Lee Revell To: Andrew Morton Cc: linux-kernel , "K.R. Foley" , Rui Nuno Capela , Florian Schmidt , Mark_H_Johnson@raytheon.com, Fernando Pablo Lopez-Lezcano , Ingo Molnar In-Reply-To: <20041012091740.GA18736@elte.hu> References: <20040922103340.GA9683@elte.hu> <20040923122838.GA9252@elte.hu> <20040923211206.GA2366@elte.hu> <20040924074416.GA17924@elte.hu> <20040928000516.GA3096@elte.hu> <20041003210926.GA1267@elte.hu> <20041004215315.GA17707@elte.hu> <20041005134707.GA32033@elte.hu> <20041007105230.GA17411@elte.hu> <1097555404.1553.18.camel@krustophenia.net> <20041012091740.GA18736@elte.hu> Content-Type: text/plain Message-Id: <1097686342.6538.31.camel@krustophenia.net> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 Date: Wed, 13 Oct 2004 12:52:23 -0400 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2239 Lines: 55 On Tue, 2004-10-12 at 05:17, Ingo Molnar wrote: > * Lee Revell wrote: > > > Just to recap, these are the three problem areas that still produce > > latencies over 500 usec on my machine. > > > > journal_clean_checkpoint_list > > you might want to send this trace to Andrew too - the primary master of > ext3 latency-breaking. > OK, Andrew, here it is. This is one of the last 2 or 3 code paths that can still produce latencies > 200 usecs on a typical machine. -- Also, I am still seeing some long latencies in the ext3 journaling code: preemption latency trace v1.0.7 on 2.6.9-rc3-mm3-VP-T3 ------------------------------------------------------- latency: 607 us, entries: 1087 (1087) | [VP:1 KP:1 SP:1 HP:1 #CPUS:1] ----------------- | task: kjournald/687, uid:0 nice:0 policy:0 rt_prio:0 ----------------- => started at: journal_commit_transaction+0x75/0x2830 => ended at: __journal_clean_checkpoint_list+0xb2/0xf0 =======> 00000001 0.000ms (+0.003ms): journal_commit_transaction (kjournald) Here is the loop: 00000002 0.003ms (+0.001ms): kfree (journal_commit_transaction) 00000001 0.004ms (+0.001ms): journal_refile_buffer (journal_commit_transaction) 00000003 0.006ms (+0.000ms): __journal_refile_buffer (journal_refile_buffer) 00000003 0.006ms (+0.001ms): __journal_unfile_buffer (journal_refile_buffer) 00000002 0.008ms (+0.000ms): journal_remove_journal_head (journal_refile_buffer) 00000003 0.008ms (+0.000ms): __journal_remove_journal_head (journal_remove_journal_head) 00000003 0.009ms (+0.000ms): __brelse (__journal_remove_journal_head) 00000003 0.010ms (+0.000ms): journal_free_journal_head (journal_remove_journal_head) 00000003 0.010ms (+0.001ms): kmem_cache_free (journal_free_journal_head) 00000001 0.011ms (+0.000ms): __brelse (journal_commit_transaction) [end loop] 00000002 0.012ms (+0.000ms): kfree (journal_commit_transaction) 00000001 0.013ms (+0.000ms): journal_refile_buffer (journal_commit_transaction) Lee - 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/