From c6d600c65ebfa10a2a10d3e9183a24527ebe2aa4 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 30 Apr 2014 13:43:56 -0600 Subject: [PATCH] blk-mq: refactor request insertion/merging Refactor the logic around adding a new bio to a software queue, so we nest the ctx->lock where we really need it (merge and insertion) and don't hold it when we don't (init and IO start accounting). Signed-off-by: Jens Axboe --- block/blk-mq.c | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 77308a84dfb2..ca51ee4aa485 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1037,17 +1037,25 @@ static void blk_mq_make_request(struct request_queue *q, struct bio *bio) } } - spin_lock(&ctx->lock); + if (!(hctx->flags & BLK_MQ_F_SHOULD_MERGE)) { + init_request_from_bio(rq, bio); - if ((hctx->flags & BLK_MQ_F_SHOULD_MERGE) && - blk_mq_attempt_merge(q, ctx, bio)) - __blk_mq_free_request(hctx, ctx, rq); - else { - blk_mq_bio_to_request(rq, bio); + spin_lock(&ctx->lock); +insert_rq: __blk_mq_insert_request(hctx, rq, false); + spin_unlock(&ctx->lock); + blk_account_io_start(rq, 1); + } else { + spin_lock(&ctx->lock); + if (!blk_mq_attempt_merge(q, ctx, bio)) { + init_request_from_bio(rq, bio); + goto insert_rq; + } + + spin_unlock(&ctx->lock); + __blk_mq_free_request(hctx, ctx, rq); } - spin_unlock(&ctx->lock); /* * For a SYNC request, send it to the hardware immediately. For an -- 2.30.2