From a31a97381cdf7dceb03b797a8faf9bc8a01c65d1 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 17 Oct 2008 13:58:29 +0200 Subject: [PATCH] block: don't use plugging on SSD devices We just want to hand the first bits of IO to the device as fast as possible. Gains a few percent on the IOPS rate. Signed-off-by: Jens Axboe --- block/blk-core.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index b1fd4f5..a824e49 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -268,8 +268,7 @@ void __generic_unplug_device(struct request_queue *q) { if (unlikely(blk_queue_stopped(q))) return; - - if (!blk_remove_plug(q)) + if (!blk_remove_plug(q) && !blk_queue_nonrot(q)) return; q->request_fn(q); @@ -1241,11 +1240,11 @@ 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 (elv_queue_empty(q)) + if (!blk_queue_nonrot(q) && elv_queue_empty(q)) blk_plug_device(q); add_request(q, req); out: - if (sync) + if (sync || blk_queue_nonrot(q)) __generic_unplug_device(q); spin_unlock_irq(q->queue_lock); return 0; -- 1.8.2.3