[Fwd: Re: [PATCH 4/4] xfs: reduce the number of pagb_lock roundtrips in xfs_alloc_clear_busy]

[Alex Elder]

Forgot to reply-all.  Sorry.	-Alex

-------- Forwarded Message --------
From: Alex Elder <aelder at sgi.com>
Reply-to: aelder at sgi.com
To: Christoph Hellwig <hch at infradead.org>
Subject: Re: [PATCH 4/4] xfs: reduce the number of pagb_lock roundtrips
in xfs_alloc_clear_busy
Date: Thu, 21 Apr 2011 15:08:32 -0500

On Mon, 2011-04-18 at 02:59 -0400, Christoph Hellwig wrote:
> Instead of finding the per-ag and then taking and releasing the pagb_lock
> for every single busy extent completed sort the list of busy extents and
> only switch betweens AGs where nessecary.  This becomes especially important
> with the online discard support which will hit this lock more often.

Looks good.

My only comment was going to be:
    Is it better to sort before when committed, or sort at
    insertion time?
But I worked through it and concluded you are doing exactly
the right thing.

Reviewed-by: Alex Elder <aelder at sgi.com>