From: Al Viro <viro@ZenIV.linux.org.uk>
To: wangdi <di.wang@whamcloud.com>
Cc: Boaz Harrosh <bharrosh@panasas.com>,
lsf-pc@lists.linux-foundation.org, linux-fsdevel@vger.kernel.org,
Jinshan Xiong <jinshan.xiong@whamcloud.com>
Subject: Re: [LSF/MM TOPIC] Parallelize file operation (like creation, unlink) under large shared directory
Date: Sun, 22 Jan 2012 20:39:36 +0000 [thread overview]
Message-ID: <20120122203936.GE23916@ZenIV.linux.org.uk> (raw)
In-Reply-To: <4F1C7223.3040301@whamcloud.com>
On Sun, Jan 22, 2012 at 12:31:31PM -0800, wangdi wrote:
> We actually already implemented this for ext4, and we saw a lot performance improvement(at least 30% improvements for open/create in a single directory)for lustre stack,
> but we want to make this improvement accessible through the VFS. Probably XFS and Btrfs could also benefit from this.
You do realize that i_mutex locking is relied upon for protection of a lot
of stuff besides the obvious (i.e. on-disk directory contents)?
I'm not saying that it's hopeless, but it's highly non-trivial; the things
like rmdir/mount races, access to ->d_parent/->d_name in a lot of code,
etc. need to be taken care of and it is a _lot_ of code review to deal
with - just to verify the correctness of such changes.
next prev parent reply other threads:[~2012-01-22 20:39 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-21 20:54 [LSF/MM TOPIC] Parallelize file operation (like creation, unlink) under large shared directory wangdi
2012-01-22 13:55 ` Boaz Harrosh
2012-01-22 20:31 ` wangdi
2012-01-22 20:39 ` Al Viro [this message]
2012-01-22 21:17 ` wangdi
2012-01-24 8:53 ` Dave Chinner
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