Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
block: consider discard merge last
If the next discard range is contiguous with the current range being
considered, it's cheaper to expand the current range than to append an
additional bio.
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
authored by
Keith Busch
and committed by
Jens Axboe
2516c246
82d20481
+6
-6
+6
-6
block/blk-merge.c
+6
-6
block/blk-merge.c
···
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static enum elv_merge blk_try_req_merge(struct request *req,
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struct request *next)
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{
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-
if (blk_discard_mergable(req))
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-
return ELEVATOR_DISCARD_MERGE;
717
-
else if (blk_rq_pos(req) + blk_rq_sectors(req) == blk_rq_pos(next))
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+
if (blk_rq_pos(req) + blk_rq_sectors(req) == blk_rq_pos(next))
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return ELEVATOR_BACK_MERGE;
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+
else if (blk_discard_mergable(req))
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+
return ELEVATOR_DISCARD_MERGE;
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return ELEVATOR_NO_MERGE;
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}
···
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enum elv_merge blk_try_merge(struct request *rq, struct bio *bio)
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{
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-
if (blk_discard_mergable(rq))
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-
return ELEVATOR_DISCARD_MERGE;
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-
else if (blk_rq_pos(rq) + blk_rq_sectors(rq) == bio->bi_iter.bi_sector)
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+
if (blk_rq_pos(rq) + blk_rq_sectors(rq) == bio->bi_iter.bi_sector)
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return ELEVATOR_BACK_MERGE;
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else if (blk_rq_pos(rq) - bio_sectors(bio) == bio->bi_iter.bi_sector)
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return ELEVATOR_FRONT_MERGE;
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+
else if (blk_discard_mergable(rq))
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+
return ELEVATOR_DISCARD_MERGE;
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return ELEVATOR_NO_MERGE;
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}
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