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    SubjectRe: [PATCH V10 18/19] block: kill QUEUE_FLAG_NO_SG_MERGE
    On Thu, Nov 15, 2018 at 04:53:05PM +0800, Ming Lei wrote:
    > Since bdced438acd83ad83a6c ("block: setup bi_phys_segments after splitting"),
    > physical segment number is mainly figured out in blk_queue_split() for
    > fast path, and the flag of BIO_SEG_VALID is set there too.
    >
    > Now only blk_recount_segments() and blk_recalc_rq_segments() use this
    > flag.
    >
    > Basically blk_recount_segments() is bypassed in fast path given BIO_SEG_VALID
    > is set in blk_queue_split().
    >
    > For another user of blk_recalc_rq_segments():
    >
    > - run in partial completion branch of blk_update_request, which is an unusual case
    >
    > - run in blk_cloned_rq_check_limits(), still not a big problem if the flag is killed
    > since dm-rq is the only user.
    >
    > Multi-page bvec is enabled now, QUEUE_FLAG_NO_SG_MERGE doesn't make sense any more.

    This commit message wasn't very clear. Is it the case that
    QUEUE_FLAG_NO_SG_MERGE is no longer set by any drivers?

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