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From: Alex Zhuravlev <Alex.Zhuravlev@Sun.COM>
To: lustre-devel@lists.lustre.org
Subject: [Lustre-devel] Some investigations on  MDS creation rate
Date: Tue, 17 Feb 2009 09:17:23 +0300	[thread overview]
Message-ID: <499A5673.4060103@sun.com> (raw)
In-Reply-To: <CB88ADF9-B0C6-41FA-AFCE-F9CA1E2416BD@Sun.COM>

Oleg Drokin wrote:
>> notice HEAD takes two ldlm locks for each create, 1.6 takes one.
> 
> What is the other one? I am looking at mdt_md_create and I see it locks 
> parent, but not child, just like b1_6.

one lock on whole parent directory (to invalidate client's cache), another
lock on part of parent directory with given hash. this is workaround for
slow creates from multiple clients due to rep-ack mechanism.

thanks, Alex

      reply	other threads:[~2009-02-17  6:17 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-02-14  8:47 [Lustre-devel] Some investigations on MDS creation rate Oleg Drokin
     [not found] ` <49982E71.80902@cray.com>
2009-02-16  0:10   ` Oleg Drokin
2009-02-16 11:11 ` Oleg Drokin
2009-02-16 15:26   ` Alex Zhuravlev
2009-02-16 21:05     ` Oleg Drokin
2009-02-17  6:17       ` Alex Zhuravlev [this message]

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