list_splice_tail() is much more faster than inserting each request one by one, given all requets in 'list' belong to same sw queue and ctx->lock is required to insert requests.
Cc: Kashyap Desai <[email protected]> Cc: Laurence Oberman <[email protected]> Cc: Omar Sandoval <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Bart Van Assche <[email protected]> Reported-by: Kashyap Desai <[email protected]> Signed-off-by: Ming Lei <[email protected]> --- block/blk-mq.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 70c65bb6c013..20b0519cb3b8 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1533,19 +1533,19 @@ void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, struct list_head *list) { + struct request *rq; + /* * preemption doesn't flush plug list, so it's possible ctx->cpu is * offline now */ - spin_lock(&ctx->lock); - while (!list_empty(list)) { - struct request *rq; - - rq = list_first_entry(list, struct request, queuelist); + list_for_each_entry(rq, list, queuelist) { BUG_ON(rq->mq_ctx != ctx); - list_del_init(&rq->queuelist); - __blk_mq_insert_req_list(hctx, rq, false); + trace_block_rq_insert(hctx->queue, rq); } + + spin_lock(&ctx->lock); + list_splice_tail(list, &ctx->rq_list); blk_mq_hctx_mark_pending(hctx, ctx); spin_unlock(&ctx->lock); } -- 2.9.5
