From: Dave Chinner <david@fromorbit.com>
To: SF Markus Elfring <elfring@users.sourceforge.net>
Cc: Julia Lawall <julia.lawall@lip6.fr>,
kernel-janitors@vger.kernel.org,
LKML <linux-kernel@vger.kernel.org>,
xfs@oss.sgi.com
Subject: Re: XFS: Fine-tuning for checks before the function call "xfs_qm_dqrele"?
Date: Thu, 2 Jul 2015 10:19:51 +1000 [thread overview]
Message-ID: <20150702001951.GX22807@dastard> (raw)
In-Reply-To: <55939BA8.1090400@users.sourceforge.net>
On Wed, Jul 01, 2015 at 09:50:00AM +0200, SF Markus Elfring wrote:
> > xfs_dqrele_inode() gets called on every inode in the inode cache,
> > and this change results in a cacheline in every inode being dirtied
> > even if they don't have dquots attached. Given the inode cache can
> > hold tens to hundreds of millions of inodes on large machines, we
> > don't want to dirty any cachelines we don't need to while walking
> > the inode cache and releasing dquots...
>
> Would it make sense to annotate checks before such function calls
> as "LIKELY"?
No - it will be random as to whether the inodes have dquots attached
or not and so a static hint is always going to be wrong for
someone....
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
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prev parent reply other threads:[~2015-07-02 0:20 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
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[not found] ` <5317A59D.4@users.sourceforge.net>
2014-11-29 16:45 ` [PATCH 1/1] XFS: Deletion of unnecessary checks before two function calls SF Markus Elfring
2014-11-30 23:09 ` Dave Chinner
2015-06-26 9:15 ` [PATCH] XFS: Delete unnecessary checks before the function call "xfs_qm_dqrele" SF Markus Elfring
2015-06-29 21:43 ` Dave Chinner
2015-07-01 7:50 ` XFS: Fine-tuning for checks before the function call "xfs_qm_dqrele"? SF Markus Elfring
2015-07-02 0:19 ` Dave Chinner [this message]
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