From 841bac2c87fc21c3ecf3bc3354855921735aeec1 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 21 Sep 2016 10:08:43 -0600 Subject: [PATCH] blk-mq: get rid of manual run of queue with __blk_mq_run_hw_queue() Two cases: 1) blk_mq_alloc_request() needlessly re-runs the queue, after calling into the tag allocation without NOWAIT set. We don't need to do that. 2) blk_mq_map_request() should just use blk_mq_run_hw_queue() with the async flag set to false. Signed-off-by: Jens Axboe Reviewed-by: Christoph Hellwig --- block/blk-mq.c | 16 ++-------------- 1 file changed, 2 insertions(+), 14 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index e0a69daddbd8..c29700010b5c 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -34,8 +34,6 @@ static DEFINE_MUTEX(all_q_mutex); static LIST_HEAD(all_q_list); -static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx); - /* * Check if any of the ctx's have pending work in this hardware queue */ @@ -228,19 +226,9 @@ struct request *blk_mq_alloc_request(struct request_queue *q, int rw, ctx = blk_mq_get_ctx(q); hctx = q->mq_ops->map_queue(q, ctx->cpu); blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx); - rq = __blk_mq_alloc_request(&alloc_data, rw, 0); - if (!rq && !(flags & BLK_MQ_REQ_NOWAIT)) { - __blk_mq_run_hw_queue(hctx); - blk_mq_put_ctx(ctx); - - ctx = blk_mq_get_ctx(q); - hctx = q->mq_ops->map_queue(q, ctx->cpu); - blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx); - rq = __blk_mq_alloc_request(&alloc_data, rw, 0); - ctx = alloc_data.ctx; - } blk_mq_put_ctx(ctx); + if (!rq) { blk_queue_exit(q); return ERR_PTR(-EWOULDBLOCK); @@ -1225,7 +1213,7 @@ static struct request *blk_mq_map_request(struct request_queue *q, blk_mq_set_alloc_data(&alloc_data, q, BLK_MQ_REQ_NOWAIT, ctx, hctx); rq = __blk_mq_alloc_request(&alloc_data, op, op_flags); if (unlikely(!rq)) { - __blk_mq_run_hw_queue(hctx); + blk_mq_run_hw_queue(hctx, false); blk_mq_put_ctx(ctx); trace_block_sleeprq(q, bio, op); -- 2.20.1