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Date:   Mon, 21 May 2018 17:12:51 +0200
From:   David Sterba <dsterba@suse.cz>
To:     Jens Axboe <axboe@kernel.dk>
Cc:     Mike Snitzer <snitzer@redhat.com>,
        Kent Overstreet <kent.overstreet@gmail.com>,
        linux-kernel@vger.kernel.org, linux-block@vger.kernel.org,
        hch@infradead.org, colyli@suse.de, darrick.wong@oracle.com,
        clm@fb.com, bacik@fb.com, linux-xfs@vger.kernel.org,
        drbd-dev@lists.linbit.com, linux-btrfs@vger.kernel.org,
        linux-raid@vger.kernel.org, neilb@suse.com
Subject: Re: [PATCH 00/13] convert block layer to bioset_init()/mempool_init()
Message-ID: <20180521151251.GX6649@twin.jikos.cz>
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On Mon, May 21, 2018 at 08:19:58AM -0600, Jens Axboe wrote:
> On 5/21/18 8:03 AM, Mike Snitzer wrote:
> > On Sun, May 20 2018 at  6:25pm -0400,
> > Kent Overstreet <kent.overstreet@gmail.com> wrote:
> > 
> >> Jens - this series does the rest of the conversions that Christoph wanted, and
> >> drops bioset_create().
> >>
> >> Only lightly tested, but the changes are pretty mechanical. Based on your
> >> for-next tree.
> > 
> > By switching 'mempool_t *' to 'mempool_t' and 'bio_set *' to 'bio_set'
> > you've altered the alignment of members in data structures.  So I'll
> > need to audit all the data structures you've modified in DM.
> > 
> > Could we get the backstory on _why_ you're making this change?
> > Would go a long way to helping me appreciate why this is a good use of
> > anyone's time.
> 
> Yeah, it's in the first series, it gets rid of a pointer indirection.

This should to be also mentioned the changelog of each patch. There are
12 subsystems changed, this could be about 10 maintainers and I guess
everybody has the same question why the change is made.

The conversion is not exactly the same in all patches, the simple
pointer -> static variable can be possibly covered by the same generic
text but as Mike points out the alignment changes should be at least
mentioned for consideration otherwise.