From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261423AbUBTWno (ORCPT ); Fri, 20 Feb 2004 17:43:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261335AbUBTWl1 (ORCPT ); Fri, 20 Feb 2004 17:41:27 -0500 Received: from mail-07.iinet.net.au ([203.59.3.39]:53441 "HELO mail.iinet.net.au") by vger.kernel.org with SMTP id S261408AbUBTWkq (ORCPT ); Fri, 20 Feb 2004 17:40:46 -0500 Message-ID: <40368CE9.9030807@cyberone.com.au> Date: Sat, 21 Feb 2004 09:40:41 +1100 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040122 Debian/1.6-1 X-Accept-Language: en MIME-Version: 1.0 To: John Chatelle CC: linux-kernel@vger.kernel.org Subject: Re: High read Latency test (Anticipatory I/O scheduler) References: <20040220202023.M9162@medent.com> In-Reply-To: <20040220202023.M9162@medent.com> Content-Type: multipart/mixed; boundary="------------050303040703000703030501" Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org This is a multi-part message in MIME format. --------------050303040703000703030501 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit John Chatelle wrote: > I haven't seen much duplicated results regarding the Robert Love article >in the February 2004 Linux Journal article, also reachable in the hyperlink: > http://www.linuxjournal.com/article.php?sid=6931 > > Although the 1st simple test: "Write starved reads" gets results comparable >to the results reported in the Article, Our results for the 2nd test: "High >Read latency" delivers results opposite our expectations... > > Hi John, Can you try the following patch please? If that doesn't help, can you show me what /sys/block/hda/queue/iosched/est_time says after your test has been running for a couple of minutes. Thanks Nick --------------050303040703000703030501 Content-Type: text/plain; name="as-exit-prob.patch" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="as-exit-prob.patch" linux-2.6-npiggin/drivers/block/as-iosched.c | 2 ++ 1 files changed, 2 insertions(+) diff -puN drivers/block/as-iosched.c~as-exit-prob drivers/block/as-iosched.c --- linux-2.6/drivers/block/as-iosched.c~as-exit-prob 2004-02-21 09:38:54.000000000 +1100 +++ linux-2.6-npiggin/drivers/block/as-iosched.c 2004-02-21 09:39:22.000000000 +1100 @@ -734,8 +734,10 @@ static int as_can_break_anticipation(str if (aic->ttime_samples == 0) { if (ad->new_ttime_mean > ad->antic_expire) return 1; +#if 0 if (ad->exit_prob > 128) return 1; +#endif } else if (aic->ttime_mean > ad->antic_expire) { /* the process thinks too much between requests */ return 1; _ --------------050303040703000703030501--