From: Mike Galbraith Subject: Re: [PATCH] Add ext3 data=guarded mode Date: Mon, 20 Apr 2009 11:07:17 +0200 Message-ID: <1240218437.7005.27.camel@marge.simson.net> References: <1239816159-6868-1-git-send-email-chris.mason@oracle.com> <1239910921.21233.98.camel@think.oraclecorp.com> <20090417180906.GA8363@amit-x200.pnq.redhat.com> <20090417201342.GF26479@mit.edu> <20090418060312.GA10943@amit-x200.pnq.redhat.com> <1240039701.6298.12.camel@marge.simson.net> <20090419062448.GA13272@amit-x200.pnq.redhat.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Theodore Tso , Chris Mason , Jan Kara , Linus Torvalds , Linux Kernel Developers List , Ext4 Developers List To: Amit Shah Return-path: Received: from mail.gmx.net ([213.165.64.20]:43764 "HELO mail.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751001AbZDTJHW (ORCPT ); Mon, 20 Apr 2009 05:07:22 -0400 In-Reply-To: <20090419062448.GA13272@amit-x200.pnq.redhat.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Sun, 2009-04-19 at 11:54 +0530, Amit Shah wrote: > On (Sat) Apr 18 2009 [09:28:21], Mike Galbraith wrote: > > Probably because you're swapping heavily, and that is perturbing your > > The variance only affects the 4k test; the other times more or less > remain the same. My box disagrees. (bumps ulimits to test 4BG... OS+swap live on sdb btw) ./test-file-zero-alloc-speed 4 /dev/sdf3 /media/root ext3 rw,_netdev,noatime,data=foo,acl,user_xattr foo=guarded 4k 225 141 80 142 361 8k 74 96 362 78 84 mm 55 57 57 57 57 foo=writeback 4k 179 264 187 125 93 8k 94 161 73 334 84 mm 57 58 57 56 57 foo=ordered 4k 81 74 76 80 75 8k 77 76 224 79 79 mm 59 56 60 58 59 foo=journal 4k 95 297 69 83 420 8k 73 139 158 80 78 mm 57 58 56 59 56 ./test-file-zero-alloc-speed 2 /dev/sdf3 /media/root ext3 rw,_netdev,noatime,data=foo,acl,user_xattr foo=guarded 4k 28 27 27 28 28 8k 28 27 27 28 27 foo=writeback 4k 27 27 27 27 27 8k 28 28 27 27 28 All journal modes seem subject to bad throughput under heavy pressure, though data=ordered seems much less likely to suffer for some reason. Major difference _seems_ to be that write()+largefile induces very much swap activity. -Mike