From mboxrd@z Thu Jan  1 00:00:00 1970
From: Mike Snitzer <snitzer@redhat.com>
Subject: Re: [PATCH v2 7/7] dm snapshot: use bufio prefetch
Date: Mon, 13 Jan 2014 17:56:52 -0500
Message-ID: <20140113225651.GA1678@redhat.com>
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To: Mikulas Patocka <mpatocka@redhat.com>
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On Mon, Jan 13 2014 at  5:00pm -0500,
Mikulas Patocka <mpatocka@redhat.com> wrote:

> No.
> 
> This changed patch inefficiently loops in bufio_prefetch_chunks for each 
> buffer that is read.

Yeah, I overlooked the importance of preserving prefetch_area (which
explains the unlikely you had).  But my intent was to make your code
less "special"; your if (DM_PREFETCH_CHUNKS) do { } while() code to
avoid the extra indentation is pretty ugly.

Given your current code, DM_PREFETCH_CHUNKS is always 12 so why not just
remove the check?