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? -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel