Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267866AbUIJW6Q (ORCPT ); Fri, 10 Sep 2004 18:58:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267968AbUIJW6P (ORCPT ); Fri, 10 Sep 2004 18:58:15 -0400 Received: from viper.oldcity.dca.net ([216.158.38.4]:42165 "HELO viper.oldcity.dca.net") by vger.kernel.org with SMTP id S267866AbUIJWyw (ORCPT ); Fri, 10 Sep 2004 18:54:52 -0400 Subject: Re: [patch] voluntary-preempt-2.6.9-rc1-bk12-R6 From: Lee Revell To: Ingo Molnar Cc: Andrew Morton , linux-kernel , felipe_alfaro@linuxmail.org, Florian Schmidt , kr@cybsft.com, Mark_H_Johnson@Raytheon.com In-Reply-To: <20040910132841.GA8552@elte.hu> References: <20040903120957.00665413@mango.fruits.de> <20040904195141.GA6208@elte.hu> <20040905140249.GA23502@elte.hu> <20040906110626.GA32320@elte.hu> <1094626562.1362.99.camel@krustophenia.net> <20040909192924.GA1672@elte.hu> <20040909130526.2b015999.akpm@osdl.org> <20040910132841.GA8552@elte.hu> Content-Type: text/plain Message-Id: <1094856888.2721.7.camel@krustophenia.net> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 Date: Fri, 10 Sep 2004 18:54:48 -0400 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2291 Lines: 59 On Fri, 2004-09-10 at 09:28, Ingo Molnar wrote: > * Andrew Morton wrote: > > > diff -puN mm/vmscan.c~swapspace-layout-improvements mm/vmscan.c > > --- 25/mm/vmscan.c~swapspace-layout-improvements 2004-06-03 21:32:51.087602712 -0700 > > +++ 25-akpm/mm/vmscan.c 2004-06-03 21:32:51.102600432 -0700 > OK, Andrew's patch seems to be an improvement. I can still cause unbounded latencies, but these only seem to happen when we fill all available RAM and swap space, at which point we start spending milliseconds at a time in scan_swap_map: preemption latency trace v1.0.7 on 2.6.9-rc1-bk12-VP-S0 ------------------------------------------------------- latency: 6032 us, entries: 550 (550) | [VP:1 KP:1 SP:1 HP:1 #CPUS:1] ----------------- | task: xfs/1098, uid:0 nice:0 policy:0 rt_prio:0 ----------------- => started at: rtc_interrupt+0x294/0x450 => ended at: get_swap_page+0x13f/0x350 =======> 00010002 0.000ms (+0.000ms): touch_preempt_timing (rtc_interrupt) 00010002 0.000ms (+0.000ms): printk (rtc_interrupt) 00010002 0.000ms (+0.001ms): vprintk (printk) 00010003 0.002ms (+0.000ms): vscnprintf (vprintk) 00010003 0.002ms (+0.002ms): vsnprintf (vscnprintf) 00010003 0.005ms (+0.004ms): number (vsnprintf) 00010003 0.009ms (+0.001ms): number (vsnprintf) 00010003 0.010ms (+0.001ms): number (vsnprintf) 00010003 0.011ms (+0.000ms): emit_log_char (vprintk) [...] 00010002 1.983ms (+0.000ms): preempt_schedule (do_IRQ) 00000003 1.984ms (+0.000ms): do_softirq (do_IRQ) 00000003 1.984ms (+0.911ms): __do_softirq (do_softirq) 00010002 2.896ms (+0.000ms): do_IRQ (scan_swap_map) 00010002 2.896ms (+0.000ms): do_IRQ (<00000008>) 00010003 2.897ms (+0.004ms): mask_and_ack_8259A (do_IRQ) 00010003 2.901ms (+0.000ms): preempt_schedule (do_IRQ) Full trace: http://krustophenia.net/testresults.php?dataset=2.6.9-rc1-bk12-S0#/var/www/2.6.9-rc1-bk12-S0/swapspace-layout-improvements-A1.txt The above are just the initial results; I am still testing this. It certainly seems like it can take a beating. Lee 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/