From 79da0644a8e0838522828f106e4049639eea6baf Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 23 Feb 2010 08:40:43 +0100 Subject: Revert "block: improve queue_should_plug() by looking at IO depths" This reverts commit fb1e75389bd06fd5987e9cda1b4e0305c782f854. "Benjamin S." reports that the patch in question causes a big drop in sequential throughput for him, dropping from 200MB/sec down to only 70MB/sec. Needs to be investigated more fully, for now lets just revert the offending commit. Conflicts: include/linux/blkdev.h Signed-off-by: Jens Axboe --- block/blk-core.c | 11 ++--------- 1 file changed, 2 insertions(+), 9 deletions(-) (limited to 'block/blk-core.c') diff --git a/block/blk-core.c b/block/blk-core.c index 718897e6d37..d1a9a0a64f9 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1147,7 +1147,7 @@ void init_request_from_bio(struct request *req, struct bio *bio) */ static inline bool queue_should_plug(struct request_queue *q) { - return !(blk_queue_nonrot(q) && blk_queue_queuing(q)); + return !(blk_queue_nonrot(q) && blk_queue_tagged(q)); } static int __make_request(struct request_queue *q, struct bio *bio) @@ -1859,15 +1859,8 @@ void blk_dequeue_request(struct request *rq) * and to it is freed is accounted as io that is in progress at * the driver side. */ - if (blk_account_rq(rq)) { + if (blk_account_rq(rq)) q->in_flight[rq_is_sync(rq)]++; - /* - * Mark this device as supporting hardware queuing, if - * we have more IOs in flight than 4. - */ - if (!blk_queue_queuing(q) && queue_in_flight(q) > 4) - set_bit(QUEUE_FLAG_CQ, &q->queue_flags); - } } /** -- cgit v1.2.3