From 8d663f34f8afcf5fc6a84c3cc4fa28cc84d58e39 Mon Sep 17 00:00:00 2001 From: Lin Feng Date: Thu, 15 Apr 2021 11:39:20 +0800 Subject: blk-mq: bypass IO scheduler's limit_depth for passthrough request Commit 01e99aeca39796003 ("blk-mq: insert passthrough request into hctx->dispatch directly") gives high priority to passthrough requests and bypass underlying IO scheduler. But as we allocate tag for such request it still runs io-scheduler's callback limit_depth, while we really want is to give full sbitmap-depth capabity to such request for acquiring available tag. blktrace shows PC requests(dmraid -s -c -i) hit bfq's limit_depth: 8,0 2 0 0.000000000 39952 1,0 m N bfq [bfq_limit_depth] wr_busy 0 sync 0 depth 8 8,0 2 1 0.000008134 39952 D R 4 [dmraid] 8,0 2 2 0.000021538 24 C R [0] 8,0 2 0 0.000035442 39952 1,0 m N bfq [bfq_limit_depth] wr_busy 0 sync 0 depth 8 8,0 2 3 0.000038813 39952 D R 24 [dmraid] 8,0 2 4 0.000044356 24 C R [0] This patch introduce a new wrapper to make code not that ugly. Signed-off-by: Lin Feng Reviewed-by: Ming Lei Link: https://lore.kernel.org/r/20210415033920.213963-1-linf@wangsu.com Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 30d2090583ad..f2e77ba97550 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -274,6 +274,12 @@ static inline bool bio_is_passthrough(struct bio *bio) return blk_op_is_scsi(op) || blk_op_is_private(op); } +static inline bool blk_op_is_passthrough(unsigned int op) +{ + return (blk_op_is_scsi(op & REQ_OP_MASK) || + blk_op_is_private(op & REQ_OP_MASK)); +} + static inline unsigned short req_get_ioprio(struct request *req) { return req->ioprio; -- cgit