From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wu Fengguang Subject: Re: [PATCH 2/2] writeback: Replace some redirty_tail() calls with requeue_io() Date: Sat, 8 Oct 2011 12:00:36 +0800 Message-ID: <20111008040036.GA30069@localhost> References: <1315442684-26754-1-git-send-email-jack@suse.cz> <1315442684-26754-2-git-send-email-jack@suse.cz> <20110908012236.GB12712@localhost> <20110908150340.GB28149@quack.suse.cz> <20110918140737.GA15366@localhost> <20111005173908.GF23467@quack.suse.cz> <20111007134347.GA6891@localhost> <20111007142201.GB30754@quack.suse.cz> <20111007142928.GA14427@localhost> <20111007144504.GC30754@quack.suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "linux-fsdevel@vger.kernel.org" , Dave Chinner , Christoph Hellwig , Chris Mason To: Jan Kara Return-path: Received: from mga14.intel.com ([143.182.124.37]:35968 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750696Ab1JHEAq (ORCPT ); Sat, 8 Oct 2011 00:00:46 -0400 Content-Disposition: inline In-Reply-To: <20111007144504.GC30754@quack.suse.cz> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Hi Jan, The test results look not good: btrfs is heavily impacted and the other filesystems are slightly impacted. I'll send you the detailed logs in private emails (too large for the mailing list). Basically I noticed many writeback_wait traces that never appear w/o this patch. In the btrfs cases that see larger regressions, I see large fluctuations in the writeout bandwidth and long disk idle periods. It's still a bit puzzling how all these happen.. 3.1.0-rc8-ioless6+ 3.1.0-rc8-ioless6-requeue+ ------------------------ ------------------------ 59.39 -82.9% 10.13 thresh=100M/btrfs-10dd-4k-8p-4096M-100M:10-X 58.68 -80.3% 11.54 thresh=100M/btrfs-1dd-4k-8p-4096M-100M:10-X 58.92 -80.0% 11.76 thresh=100M/btrfs-2dd-4k-8p-4096M-100M:10-X 38.02 -1.0% 37.65 thresh=100M/ext3-10dd-4k-8p-4096M-100M:10-X 45.20 +1.7% 45.96 thresh=100M/ext3-1dd-4k-8p-4096M-100M:10-X 42.50 -0.8% 42.14 thresh=100M/ext3-2dd-4k-8p-4096M-100M:10-X 47.50 -2.5% 46.32 thresh=100M/ext4-10dd-4k-8p-4096M-100M:10-X 58.18 -3.0% 56.41 thresh=100M/ext4-1dd-4k-8p-4096M-100M:10-X 55.79 -2.1% 54.63 thresh=100M/ext4-2dd-4k-8p-4096M-100M:10-X 44.89 -19.3% 36.23 thresh=100M/xfs-10dd-4k-8p-4096M-100M:10-X 58.06 -4.2% 55.64 thresh=100M/xfs-1dd-4k-8p-4096M-100M:10-X 51.94 -1.1% 51.35 thresh=100M/xfs-2dd-4k-8p-4096M-100M:10-X 60.29 -35.9% 38.63 thresh=1G/btrfs-100dd-4k-8p-4096M-1024M:10-X 58.80 -33.2% 39.25 thresh=1G/btrfs-10dd-4k-8p-4096M-1024M:10-X 58.53 -21.5% 45.93 thresh=1G/btrfs-1dd-4k-8p-4096M-1024M:10-X 31.96 -4.7% 30.44 thresh=1G/ext3-100dd-4k-8p-4096M-1024M:10-X 36.19 -1.0% 35.82 thresh=1G/ext3-10dd-4k-8p-4096M-1024M:10-X 45.03 -2.7% 43.80 thresh=1G/ext3-1dd-4k-8p-4096M-1024M:10-X 51.47 -2.6% 50.14 thresh=1G/ext4-100dd-4k-8p-4096M-1024M:10-X 56.19 -1.0% 55.64 thresh=1G/ext4-10dd-4k-8p-4096M-1024M:10-X 58.41 -1.0% 57.84 thresh=1G/ext4-1dd-4k-8p-4096M-1024M:10-X 43.44 -8.4% 39.77 thresh=1G/xfs-100dd-4k-8p-4096M-1024M:10-X 49.83 -3.3% 48.18 thresh=1G/xfs-10dd-4k-8p-4096M-1024M:10-X 52.70 -0.8% 52.26 thresh=1G/xfs-1dd-4k-8p-4096M-1024M:10-X 57.12 -85.5% 8.27 thresh=8M/btrfs-10dd-4k-8p-4096M-8M:10-X 59.29 -84.7% 9.05 thresh=8M/btrfs-1dd-4k-8p-4096M-8M:10-X 59.23 -84.9% 8.97 thresh=8M/btrfs-2dd-4k-8p-4096M-8M:10-X 33.63 -3.3% 32.51 thresh=8M/ext3-10dd-4k-8p-4096M-8M:10-X 48.30 -4.7% 46.03 thresh=8M/ext3-1dd-4k-8p-4096M-8M:10-X 46.77 -4.5% 44.69 thresh=8M/ext3-2dd-4k-8p-4096M-8M:10-X 36.58 -2.2% 35.77 thresh=8M/ext4-10dd-4k-8p-4096M-8M:10-X 57.35 -0.3% 57.16 thresh=8M/ext4-1dd-4k-8p-4096M-8M:10-X 52.82 -1.5% 52.04 thresh=8M/ext4-2dd-4k-8p-4096M-8M:10-X 32.19 -4.5% 30.74 thresh=8M/xfs-10dd-4k-8p-4096M-8M:10-X 55.86 -1.4% 55.09 thresh=8M/xfs-1dd-4k-8p-4096M-8M:10-X 48.96 -33.1% 32.74 thresh=8M/xfs-2dd-4k-8p-4096M-8M:10-X 1810.02 -22.1% 1410.49 TOTAL Thanks, Fengguang