From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Galbraith Subject: Re: [tbench regression fixes]: digging out smelly deadmen. Date: Sun, 26 Oct 2008 11:23:19 +0100 Message-ID: <1225016599.5403.15.camel@marge.simson.net> References: <20081024.221653.23695396.davem@davemloft.net> <1224914333.3822.18.camel@marge.simson.net> <1224917623.4929.15.camel@marge.simson.net> <20081025.002420.82739316.davem@davemloft.net> <1225010790.8566.22.camel@marge.simson.net> <1225011648.27415.4.camel@twins> <20081026021153.47878580.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Peter Zijlstra , Jiri Kosina , David Miller , rjw@sisk.pl, Ingo Molnar , s0mbre@tservice.net.ru, linux-kernel@vger.kernel.org, netdev@vger.kernel.org To: Andrew Morton Return-path: Received: from mail.gmx.net ([213.165.64.20]:36730 "HELO mail.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751137AbYJZKXb (ORCPT ); Sun, 26 Oct 2008 06:23:31 -0400 In-Reply-To: <20081026021153.47878580.akpm@linux-foundation.org> Sender: netdev-owner@vger.kernel.org List-ID: On Sun, 2008-10-26 at 02:11 -0700, Andrew Morton wrote: > Was this when we decreased the default value of > /proc/sys/vm/dirty_ratio, perhaps? dbench is sensitive to that. Wow, indeed. I fired up an ext2 disk to take kjournald out of the picture (dunno, just a transient thought). Stock settings produced three perma-wrecks in a row. With it bumped to 50, three very considerably nicer results in a row appeared. =EF=BB=BF2.6.26.7-smp dirty_ratio =3D 10 (stock) Throughput 36.3649 MB/sec 160 procs Throughput 47.0787 MB/sec 160 procs Throughput 88.2055 MB/sec 160 procs 2.6.26.7-smp dirty_ratio =3D 50 Throughput 1009.98 MB/sec 160 procs Throughput 1101.57 MB/sec 160 procs Throughput 943.205 MB/sec 160 procs =EF=BB=BF -Mike