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Date:   Mon, 17 Aug 2020 08:22:24 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Baolin Wang <baolin.wang@linux.alibaba.com>
Cc:     axboe@kernel.dk, ming.lei@redhat.com, hch@lst.de,
        baolin.wang7@gmail.com, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH RESEND 2/5] block: Remove redundant
 blk_mq_sched_allow_merge() validation
Message-ID: <20200817062224.GB12248@lst.de>
References: <cover.1597637287.git.baolin.wang@linux.alibaba.com> <b9d51f4bc9f0ff4ec3b8fb7fa6dc366afd69290e.1597637287.git.baolin.wang@linux.alibaba.com>
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On Mon, Aug 17, 2020 at 12:09:16PM +0800, Baolin Wang wrote:
> Only software queue and kyber IO scheduler will call blk_mq_bio_list_merge()
> to merge a bio, and kyber IO scheduler did not implement the ops->allow_merge().

Please line wrap your changelogs after 73 characters.

> Thus we can remove the redundant blk_mq_sched_allow_merge() in
> blk_mq_bio_list_merge() function.

This seems potentially dangerous, and I don't think it really buys
us much.