From 4ea58fe456c21bb259a7cbf8498946f86e9b84aa Mon Sep 17 00:00:00 2001 From: Kemeng Shi Date: Wed, 18 Jan 2023 17:37:23 +0800 Subject: blk-mq: remove unnecessary error count and check in blk_mq_dispatch_rq_list blk_mq_dispatch_rq_list will notify if hctx is busy in return bool. It will return true if we are not busy and can handle more and return false on the opposite. Inside blk_mq_dispatch_rq_list, errors is only used if list is empty and we will return true if list is empty and (errors + queued) != 0. There are three types of status returned from request: -busy error BLK_STS*_RESOURCE: the failed request will be added back to list and list will not be empty. -BLK_STS_OK: We count queued for BLK_STS_OK -rest error: We count errors for rest error If list is empty, there is no request gets busy error then (errors + queued) will be total requests in the list which is checked not empty at beginning of blk_mq_dispatch_rq_list. So (errors + queued) != 0 is always met if list is empty. Then the (errors + queued) != 0 check and errors number count is not needed. Signed-off-by: Kemeng Shi Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-mq.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) (limited to 'block/blk-mq.c') diff --git a/block/blk-mq.c b/block/blk-mq.c index 07256cdb3d2d..6f29e6ceecd1 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2033,7 +2033,7 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list, enum prep_dispatch prep; struct request_queue *q = hctx->queue; struct request *rq, *nxt; - int errors, queued; + int queued; blk_status_t ret = BLK_STS_OK; LIST_HEAD(zone_list); bool needs_resource = false; @@ -2044,7 +2044,7 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list, /* * Now process all the entries, sending them to the driver. */ - errors = queued = 0; + queued = 0; do { struct blk_mq_queue_data bd; @@ -2097,7 +2097,6 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list, needs_resource = true; break; default: - errors++; blk_mq_end_request(rq, ret); } } while (!list_empty(list)); @@ -2175,10 +2174,10 @@ out: blk_mq_update_dispatch_busy(hctx, true); return false; - } else - blk_mq_update_dispatch_busy(hctx, false); + } - return (queued + errors) != 0; + blk_mq_update_dispatch_busy(hctx, false); + return true; } /** -- cgit v1.2.3