From: Fengguang Wu <fengguang.wu@intel.com>
To: Theodore Ts'o <tytso@mit.edu>, Marti Raudsepp <marti@juffo.org>,
Kernel hackers <linux-kernel@vger.kernel.org>,
ext4 hackers <linux-ext4@vger.kernel.org>,
maze@google.com, "Shi, Alex" <alex.shi@intel.com>,
linux-fsdevel@vger.kernel.org
Cc: linux RAID <linux-raid@vger.kernel.org>,
NeilBrown <neilb@suse.de>, Li Shaohua <shli@fusionio.com>
Subject: Re: ext4 write performance regression in 3.6-rc1 on RAID0/5
Date: Fri, 17 Aug 2012 22:25:26 +0800 [thread overview]
Message-ID: <20120817142526.GA1059@localhost> (raw)
In-Reply-To: <20120817134039.GB11439@thunk.org>
[CC md list]
On Fri, Aug 17, 2012 at 09:40:39AM -0400, Theodore Ts'o wrote:
> On Fri, Aug 17, 2012 at 02:09:15PM +0800, Fengguang Wu wrote:
> > Ted,
> >
> > I find ext4 write performance dropped by 3.3% on average in the
> > 3.6-rc1 merge window. xfs and btrfs are fine.
> >
> > Two machines are tested. The performance regression happens in the
> > lkp-nex04 machine, which is equipped with 12 SSD drives. lkp-st02 does
> > not see regression, which is equipped with HDD drives. I'll continue
> > to repeat the tests and report variations.
>
> Hmm... I've checked out the commits in "git log v3.5..v3.6-rc1 --
> fs/ext4 fs/jbd2" and I don't see anything that I would expect would
> cause that. The are the lock elimination changes for Direct I/O
> overwrites, but that shouldn't matter for your tests which are
> measuring buffered writes, correct?
>
> Is there any chance you could do me a favor and do a git bisect
> restricted to commits involving fs/ext4 and fs/jbd2?
I noticed that the regressions all happen in the RAID0/RAID5 cases.
So it may be some interactions between the RAID/ext4 code?
I'll try to get some ext2/3 numbers, which should have less changes on the fs side.
wfg@bee /export/writeback% ./compare -g ext4 lkp-nex04/*/*-{3.5.0,3.6.0-rc1+}
3.5.0 3.6.0-rc1+
------------------------ ------------------------
720.62 -1.5% 710.16 lkp-nex04/JBOD-12HDD-thresh=1000M/ext4-100dd-1-3.5.0
706.04 -0.0% 705.86 lkp-nex04/JBOD-12HDD-thresh=1000M/ext4-10dd-1-3.5.0
702.86 -0.2% 701.74 lkp-nex04/JBOD-12HDD-thresh=1000M/ext4-1dd-1-3.5.0
702.41 -0.0% 702.06 lkp-nex04/JBOD-12HDD-thresh=1000M/ext4-1dd-2-3.5.0
779.52 +6.5% 830.11 lkp-nex04/JBOD-12HDD-thresh=100M/ext4-100dd-1-3.5.0
646.70 +4.9% 678.59 lkp-nex04/JBOD-12HDD-thresh=100M/ext4-10dd-1-3.5.0
704.49 +2.6% 723.00 lkp-nex04/JBOD-12HDD-thresh=100M/ext4-1dd-1-3.5.0
704.21 +1.2% 712.47 lkp-nex04/JBOD-12HDD-thresh=100M/ext4-1dd-2-3.5.0
705.26 -1.2% 696.61 lkp-nex04/JBOD-12HDD-thresh=8G/ext4-100dd-1-3.5.0
703.37 +0.1% 703.76 lkp-nex04/JBOD-12HDD-thresh=8G/ext4-10dd-1-3.5.0
701.66 -0.1% 700.83 lkp-nex04/JBOD-12HDD-thresh=8G/ext4-1dd-1-3.5.0
701.17 +0.0% 701.36 lkp-nex04/JBOD-12HDD-thresh=8G/ext4-1dd-2-3.5.0
675.08 -10.5% 604.29 lkp-nex04/RAID0-12HDD-thresh=1000M/ext4-100dd-1-3.5.0
676.52 -2.7% 658.38 lkp-nex04/RAID0-12HDD-thresh=1000M/ext4-10dd-1-3.5.0
512.70 +4.0% 533.22 lkp-nex04/RAID0-12HDD-thresh=1000M/ext4-1dd-1-3.5.0
524.61 -0.3% 522.90 lkp-nex04/RAID0-12HDD-thresh=1000M/ext4-1dd-2-3.5.0
709.76 -15.7% 598.44 lkp-nex04/RAID0-12HDD-thresh=100M/ext4-100dd-1-3.5.0
681.39 -2.1% 667.25 lkp-nex04/RAID0-12HDD-thresh=100M/ext4-10dd-1-3.5.0
524.16 +0.8% 528.25 lkp-nex04/RAID0-12HDD-thresh=100M/ext4-1dd-2-3.5.0
699.77 -19.2% 565.54 lkp-nex04/RAID0-12HDD-thresh=8G/ext4-100dd-1-3.5.0
675.79 -1.9% 663.17 lkp-nex04/RAID0-12HDD-thresh=8G/ext4-10dd-1-3.5.0
484.84 -7.4% 448.83 lkp-nex04/RAID0-12HDD-thresh=8G/ext4-1dd-1-3.5.0
470.40 -3.2% 455.31 lkp-nex04/RAID0-12HDD-thresh=8G/ext4-1dd-2-3.5.0
167.97 -38.7% 103.03 lkp-nex04/RAID5-12HDD-thresh=1000M/ext4-100dd-1-3.5.0
243.67 -9.1% 221.41 lkp-nex04/RAID5-12HDD-thresh=1000M/ext4-10dd-1-3.5.0
248.98 +12.2% 279.33 lkp-nex04/RAID5-12HDD-thresh=1000M/ext4-1dd-1-3.5.0
208.45 +14.1% 237.86 lkp-nex04/RAID5-12HDD-thresh=1000M/ext4-1dd-2-3.5.0
71.18 -34.2% 46.82 lkp-nex04/RAID5-12HDD-thresh=100M/ext4-100dd-1-3.5.0
145.84 -7.3% 135.25 lkp-nex04/RAID5-12HDD-thresh=100M/ext4-10dd-1-3.5.0
255.22 +6.7% 272.35 lkp-nex04/RAID5-12HDD-thresh=100M/ext4-1dd-1-3.5.0
243.09 +20.7% 293.30 lkp-nex04/RAID5-12HDD-thresh=100M/ext4-1dd-2-3.5.0
209.24 -23.6% 159.96 lkp-nex04/RAID5-12HDD-thresh=8G/ext4-100dd-1-3.5.0
243.73 -10.9% 217.28 lkp-nex04/RAID5-12HDD-thresh=8G/ext4-10dd-1-3.5.0
214.25 +5.6% 226.32 lkp-nex04/RAID5-12HDD-thresh=8G/ext4-1dd-1-3.5.0
207.16 +13.4% 234.98 lkp-nex04/RAID5-12HDD-thresh=8G/ext4-1dd-2-3.5.0
17572.12 -1.9% 17240.05 TOTAL write_bw
Thanks,
Fengguang
next prev parent reply other threads:[~2012-08-17 14:25 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-15 18:33 NULL pointer dereference in ext4_ext_remove_space on 3.5.1 Marti Raudsepp
2012-08-16 2:46 ` Theodore Ts'o
2012-08-16 11:10 ` Fengguang Wu
2012-08-16 15:25 ` Theodore Ts'o
2012-08-16 20:21 ` Maciej Żenczykowski
2012-08-16 20:21 ` Maciej Żenczykowski
2012-08-16 21:19 ` Theodore Ts'o
2012-08-16 21:19 ` Theodore Ts'o
2012-08-16 21:40 ` Maciej Żenczykowski
2012-08-16 22:26 ` Theodore Ts'o
2012-08-16 22:44 ` Maciej Żenczykowski
2012-08-17 6:01 ` Fengguang Wu
2012-08-17 13:15 ` Theodore Ts'o
2012-08-17 13:22 ` Fengguang Wu
2012-08-17 13:50 ` [PATCH] ext4: fix kernel BUG on large-scale rm -rf commands Theodore Ts'o
2012-08-17 17:48 ` NULL pointer dereference in ext4_ext_remove_space on 3.5.1 Christoph Hellwig
2012-08-17 20:34 ` Theodore Ts'o
2012-08-17 20:34 ` Theodore Ts'o
2012-08-17 21:05 ` Christoph Hellwig
2012-08-17 21:05 ` Christoph Hellwig
2012-08-17 22:55 ` Dave Chinner
2012-08-17 22:55 ` Dave Chinner
2012-08-17 23:11 ` Theodore Ts'o
2012-08-17 23:11 ` Theodore Ts'o
2012-08-17 6:09 ` ext4 write performance regression in 3.6-rc1 Fengguang Wu
2012-08-17 13:40 ` Theodore Ts'o
2012-08-17 14:13 ` Fengguang Wu
2012-08-17 14:25 ` Fengguang Wu [this message]
[not found] ` <20120817151318.GA2341@localhost>
2012-08-17 15:37 ` ext4 write performance regression in 3.6-rc1 on RAID0/5 Theodore Ts'o
2012-08-17 20:44 ` NeilBrown
2012-08-21 9:42 ` Fengguang Wu
2012-08-21 12:07 ` Fengguang Wu
[not found] ` <20120822035702.GF2570@yliu-dev.sh.intel.com>
2012-08-22 4:07 ` Shaohua Li
2012-08-22 5:39 ` Yuanhan Liu
2012-08-22 6:00 ` NeilBrown
2012-08-22 6:31 ` Yuanhan Liu
2012-08-22 7:14 ` Andreas Dilger
2012-08-22 20:47 ` Dan Williams
2012-08-22 21:59 ` NeilBrown
2012-09-17 12:21 ` NULL pointer dereference in ext4_ext_remove_space on 3.5.1 Dmitry Monakhov
2012-09-17 13:52 ` Theodore Ts'o
2012-09-17 14:48 ` Dmitry Monakhov
2012-08-16 9:00 ` Fengguang Wu
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