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From: Avi Kivity <avi@argo.co.il>
To: Al Viro <viro@ftp.linux.org.uk>
Cc: Josef Sipek <jsipek@fsl.cs.sunysb.edu>,
	lkml@pengaru.com, linux-kernel@vger.kernel.org
Subject: Re: rename() contention (BUG?)
Date: Thu, 26 Oct 2006 23:19:56 +0200	[thread overview]
Message-ID: <4541267C.8040004@argo.co.il> (raw)
In-Reply-To: <20061026192219.GL29920@ftp.linux.org.uk>

Al Viro wrote:
> On Thu, Oct 26, 2006 at 08:43:34PM +0200, Avi Kivity wrote:
>   
>> The changes make the mutex more efficient, but won't decrease the 
>> contention.  It seems that all renames in one filesystem are serialized, 
>> and if the renames require I/O (which is certainly the case with nfs), 
>> rename throughput is severely limited.
>>     
>
> 	They are, and for a good reason.  For details see
> Documentation/filesystems/directory-locking.
>   

Is it possible to lock only the common subtree of the two paths?

Perhaps walk towards the root of the tree, starting with the deeper 
path, locking one component at a time.  Then walk both paths together 
locking components ordered by something to avoid deadlock.

-- 
Do not meddle in the internals of kernels, for they are subtle and quick to panic.


  reply	other threads:[~2006-10-26 21:20 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-10-25 20:56 rename() contention (BUG?) lkml
2006-10-25 21:13 ` Josef Sipek
2006-10-26 18:43   ` Avi Kivity
2006-10-26 19:22     ` Al Viro
2006-10-26 21:19       ` Avi Kivity [this message]
2006-10-26 21:37         ` Al Viro

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