Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751229AbVIRNnk (ORCPT ); Sun, 18 Sep 2005 09:43:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751231AbVIRNnk (ORCPT ); Sun, 18 Sep 2005 09:43:40 -0400 Received: from [212.76.84.86] ([212.76.84.86]:57604 "EHLO raad.intranet") by vger.kernel.org with ESMTP id S1751229AbVIRNnj (ORCPT ); Sun, 18 Sep 2005 09:43:39 -0400 From: Al Boldi To: Denis Vlasenko Subject: Re: Eradic disk access during reads Date: Sun, 18 Sep 2005 16:40:19 +0300 User-Agent: KMail/1.5 Cc: Willy Tarreau , linux-kernel@vger.kernel.org References: <200509170717.03439.a1426z@gawab.com> <200509171918.17658.a1426z@gawab.com> <200509181400.27004.vda@ilport.com.ua> In-Reply-To: <200509181400.27004.vda@ilport.com.ua> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200509181640.19984.a1426z@gawab.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2783 Lines: 70 Denis Vlasenko wrote: > On Saturday 17 September 2005 19:38, Al Boldi wrote: > > > # dd if=/dev/hda of=/dev/null bs=16M > > 2.4.31 # nmeter t6 c x i b d100 > > 18:56:36.009981 cpu [SSSSSSSS..] ctx 145 int 86 bio 4.7M 0 > > 18:56:36.110327 cpu [SSSSSSSS..] ctx 145 int 87 bio 4.8M 0 > > 18:56:36.210735 cpu [SSSSSSSS..] ctx 139 int 88 bio 4.7M 0 > > 18:56:36.310315 cpu [SSSSSSSS..] ctx 142 int 85 bio 4.7M 0 > > > > 2.6.13 # nmeter t6 c x i b d100 > > 18:09:22.117959 cpu [SSSSSSSSSD] ctx 80 int 47 bio 4.7M 0 > > 18:09:22.217932 cpu [SSSSSSDDDD] ctx 83 int 48 bio 4.8M 0 > > 18:09:22.319200 cpu [SSSSDDDDDI] ctx 81 int 56 bio 4.7M 28k > > 18:09:22.407979 cpu [SSSSSSSSSD] ctx 60 int 38 bio 3.8M 0 > > 18:09:22.517960 cpu [SSSSSSSSDI] ctx 95 int 61 bio 5.2M 52k > > Well, I do not see any bursts you mention... Can you try 2.4.31? > Anyway, my data: > 13:52:09.201450 cpu [SSSSSSDDII] ctx 34 int 142 bio 4.1M 0 > 13:52:09.301176 cpu [SSSSSSSDDI] ctx 39 int 138 bio 3.8M 0 > 13:52:09.401806 cpu [SSSSSSSSDI] ctx 55 int 157 bio 4.3M 0 > 13:52:09.501077 cpu [SSSSDDDDDI] ctx 32 int 121 bio 2.2M 0 > 13:52:09.601067 cpu [SSSDDDDDDD] ctx 24 int 127 bio 1.7M 0 > 13:52:09.701108 cpu [SSSSSSSDDI] ctx 50 int 153 bio 4.1M 0 > 13:52:09.802156 cpu [SSSSDDDDII] ctx 34 int 139 bio 2.7M 0 > 13:52:09.902026 cpu [SSSSSSSSDD] ctx 44 int 152 bio 4.0M 0 > 13:52:10.002041 cpu [SSSSDDDDDI] ctx 39 int 126 bio 2.2M 0 > 13:52:10.100997 cpu [SSSSDDDDDI] ctx 46 int 129 bio 2.7M 0 > 13:52:10.201964 cpu [SSSSSSSDDI] ctx 57 int 139 bio 3.6M 0 > 13:52:10.303468 cpu [SSSSDDDDDI] ctx 34 int 133 bio 2.2M 0 > 13:52:10.401523 cpu [SSSSSSSDDI] ctx 50 int 145 bio 3.6M 4096 > 13:52:10.500934 cpu [SSSSSSSSII] ctx 66 int 139 bio 4.1M 0 Does not look smooth. > /dev/hda: > UDMA modes: udma0 udma1 udma2 udma3 udma4 *udma5 same here. > My CPU is not that new: PII - 400Mhz here. > hdc (an old disk): > 13:52:40.201718 cpu [SSSDDDDDDD] ctx 26 int 112 bio 1.2M 0 > 13:52:40.301569 cpu [SSDDDDDDDD] ctx 28 int 109 bio 1.2M 0 > 13:52:40.402552 cpu [SSDDDDDDDI] ctx 23 int 111 bio 1.2M 0 > 13:52:40.502535 cpu [SSDDDDDDDD] ctx 22 int 110 bio 1.2M 0 > 13:52:40.601507 cpu [SSDDDDDDDI] ctx 26 int 111 bio 1.2M 0 > 13:52:40.701493 cpu [SSDDDDDDDD] ctx 23 int 110 bio 1.2M 0 Looks smooth. Also, great meter! Best of all does not hog the CPU! Could you add a top3 procs display? Thanks! -- Al - 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/