diff options
| -rw-r--r-- | block/blk-core.c | 1 | ||||
| -rw-r--r-- | block/blk-mq.c | 23 | ||||
| -rw-r--r-- | include/linux/blkdev.h | 1 |
3 files changed, 20 insertions, 5 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index be9233400314..d107d016b92b 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1780,6 +1780,7 @@ void blk_start_plug(struct blk_plug *plug) INIT_LIST_HEAD(&plug->mq_list); INIT_LIST_HEAD(&plug->cb_list); plug->rq_count = 0; + plug->multiple_queues = false; /* * Store ordering should not be needed here, since a potential diff --git a/block/blk-mq.c b/block/blk-mq.c index 5f4b93f424b4..2a1a653a8054 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1677,7 +1677,8 @@ void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) list_splice_init(&plug->mq_list, &list); plug->rq_count = 0; - list_sort(NULL, &list, plug_rq_cmp); + if (plug->rq_count > 2 && plug->multiple_queues) + list_sort(NULL, &list, plug_rq_cmp); this_q = NULL; this_hctx = NULL; @@ -1866,6 +1867,20 @@ void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx, } } +static void blk_add_rq_to_plug(struct blk_plug *plug, struct request *rq) +{ + list_add_tail(&rq->queuelist, &plug->mq_list); + plug->rq_count++; + if (!plug->multiple_queues && !list_is_singular(&plug->mq_list)) { + struct request *tmp; + + tmp = list_first_entry(&plug->mq_list, struct request, + queuelist); + if (tmp->q != rq->q) + plug->multiple_queues = true; + } +} + static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) { const int is_sync = op_is_sync(bio->bi_opf); @@ -1932,8 +1947,7 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) trace_block_plug(q); } - list_add_tail(&rq->queuelist, &plug->mq_list); - plug->rq_count++; + blk_add_rq_to_plug(plug, rq); } else if (plug && !blk_queue_nomerges(q)) { blk_mq_bio_to_request(rq, bio); @@ -1950,8 +1964,7 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) list_del_init(&same_queue_rq->queuelist); plug->rq_count--; } - list_add_tail(&rq->queuelist, &plug->mq_list); - plug->rq_count++; + blk_add_rq_to_plug(plug, rq); blk_mq_put_ctx(data.ctx); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 02732cae6080..08d940f85fa0 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1131,6 +1131,7 @@ struct blk_plug { struct list_head mq_list; /* blk-mq requests */ struct list_head cb_list; /* md requires an unplug callback */ unsigned short rq_count; + bool multiple_queues; }; #define BLK_MAX_REQUEST_COUNT 16 #define BLK_PLUG_FLUSH_SIZE (128 * 1024) |