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| author | Jens Axboe <jens.axboe@oracle.com> | 2009-04-06 14:48:06 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-04-06 08:04:54 -0700 |
| commit | 644b2d99b7a8677a56909a7b1fde31677eba4471 (patch) | |
| tree | 5271613f4fd9e6fbf11c16aff8dec8f1946b2234 /block | |
| parent | 4194b1eaf18ddc3eee9597e8800b6d2ffdfd3614 (diff) | |
| download | blackbird-op-linux-644b2d99b7a8677a56909a7b1fde31677eba4471.tar.gz blackbird-op-linux-644b2d99b7a8677a56909a7b1fde31677eba4471.zip | |
block: enabling plugging on SSD devices that don't do queuing
For the older SSD devices that don't do command queuing, we do want to
enable plugging to get better merging.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-core.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index a32b571aaaa2..c4198f083e5b 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1136,6 +1136,15 @@ void init_request_from_bio(struct request *req, struct bio *bio) blk_rq_bio_prep(req->q, req, bio); } +/* + * Only disabling plugging for non-rotational devices if it does tagging + * as well, otherwise we do need the proper merging + */ +static inline bool queue_should_plug(struct request_queue *q) +{ + return !(blk_queue_nonrot(q) && blk_queue_tagged(q)); +} + static int __make_request(struct request_queue *q, struct bio *bio) { struct request *req; @@ -1242,11 +1251,11 @@ get_rq: if (test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags) || bio_flagged(bio, BIO_CPU_AFFINE)) req->cpu = blk_cpu_to_group(smp_processor_id()); - if (!blk_queue_nonrot(q) && elv_queue_empty(q)) + if (queue_should_plug(q) && elv_queue_empty(q)) blk_plug_device(q); add_request(q, req); out: - if (unplug || blk_queue_nonrot(q)) + if (unplug || !queue_should_plug(q)) __generic_unplug_device(q); spin_unlock_irq(q->queue_lock); return 0; |
