From: Theodore Ts'o <tytso@mit.edu>
To: Fengguang Wu <fengguang.wu@intel.com>
Cc: 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
Subject: Re: ext4 write performance regression in 3.6-rc1
Date: Fri, 17 Aug 2012 09:40:39 -0400 [thread overview]
Message-ID: <20120817134039.GB11439@thunk.org> (raw)
In-Reply-To: <20120817060915.GB28786@localhost>
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?
Many thanks,
- Ted
next prev parent reply other threads:[~2012-08-17 13:40 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CABRT9RAOhaxcYdCxMn5neJ9WT85r=h=7WgZ2dmLaOs-MMqDW9A@mail.gmail.com>
[not found] ` <20120816024654.GB3781@thunk.org>
[not found] ` <20120816111051.GA16036@localhost>
[not found] ` <20120816152513.GA31346@thunk.org>
2012-08-17 6:09 ` ext4 write performance regression in 3.6-rc1 Fengguang Wu
2012-08-17 13:40 ` Theodore Ts'o [this message]
2012-08-17 14:13 ` Fengguang Wu
2012-08-17 14:25 ` ext4 write performance regression in 3.6-rc1 on RAID0/5 Fengguang Wu
[not found] ` <20120817151318.GA2341@localhost>
2012-08-17 15:37 ` 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 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
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