Received: with ECARTIS (v1.0.0; list xfs); Fri, 12 Jan 2007 11:57:07 -0800 (PST) Received: from lucidpixels.com (lucidpixels.com [66.45.37.187]) by oss.sgi.com (8.12.10/8.12.10/SuSE Linux 0.7) with ESMTP id l0CJusqw017594 for ; Fri, 12 Jan 2007 11:56:55 -0800 Received: by lucidpixels.com (Postfix, from userid 1001) id A89A31A000257; Fri, 12 Jan 2007 14:56:00 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by lucidpixels.com (Postfix) with ESMTP id A17EEA000257; Fri, 12 Jan 2007 14:56:00 -0500 (EST) Date: Fri, 12 Jan 2007 14:56:00 -0500 (EST) From: Justin Piszcz X-X-Sender: jpiszcz@p34.internal.lan To: Al Boldi cc: linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, xfs@oss.sgi.com Subject: Re: Linux Software RAID 5 Performance Optimizations: 2.6.19.1: (211MB/s read & 195MB/s write) In-Reply-To: <200701122235.30288.a1426z@gawab.com> Message-ID: References: <200701122235.30288.a1426z@gawab.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-archive-position: 10277 X-ecartis-version: Ecartis v1.0.0 Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com X-original-sender: jpiszcz@lucidpixels.com Precedence: bulk X-list: xfs Content-Length: 1116 Lines: 38 On Fri, 12 Jan 2007, Al Boldi wrote: > Justin Piszcz wrote: > > RAID 5 TWEAKED: 1:06.41 elapsed @ 60% CPU > > > > This should be 1:14 not 1:06(was with a similarly sized file but not the > > same) the 1:14 is the same file as used with the other benchmarks. and to > > get that I used 256mb read-ahead and 16384 stripe size ++ 128 > > max_sectors_kb (same size as my sw raid5 chunk size) > > max_sectors_kb is probably your key. On my system I get twice the read > performance by just reducing max_sectors_kb from default 512 to 192. > > Can you do a fresh reboot to shell and then: > $ cat /sys/block/hda/queue/* > $ cat /proc/meminfo > $ echo 3 > /proc/sys/vm/drop_caches > $ dd if=/dev/hda of=/dev/null bs=1M count=10240 > $ echo 192 > /sys/block/hda/queue/max_sectors_kb > $ echo 3 > /proc/sys/vm/drop_caches > $ dd if=/dev/hda of=/dev/null bs=1M count=10240 > > > Thanks! > > -- > Al > > - > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Ok. sec