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authorLiu Song <liusong@linux.alibaba.com>2022-09-21 11:32:03 +0800
committerJens Axboe <axboe@kernel.dk>2022-09-24 09:02:30 -0600
commitf168420c62e7a106961f2489a89f6ade84fe3f27 (patch)
treedf4dbd2492ff7150eebfdafb3135ae8a242556d8 /block/blk-mq.c
parent81c7a63abc7c0be572b4f853e913ce93a34f6e1b (diff)
downloadlinux-f168420c62e7a106961f2489a89f6ade84fe3f27.tar.gz
blk-mq: don't redirect completion for hctx withs only one ctx mapping
High-performance NVMe devices usually support a large hw queues, which
ensures a 1:1 mapping of hctx and ctx. In this case there will be no
remote request, so we don't need to care about it.

Signed-off-by: Liu Song <liusong@linux.alibaba.com>
Link: https://lore.kernel.org/r/1663731123-81536-1-git-send-email-liusong@linux.alibaba.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-mq.c')
-rw-r--r--block/blk-mq.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 29bb48de5bda..496085132899 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1093,10 +1093,12 @@ bool blk_mq_complete_request_remote(struct request *rq)
 	WRITE_ONCE(rq->state, MQ_RQ_COMPLETE);
 
 	/*
-	 * For a polled request, always complete locally, it's pointless
-	 * to redirect the completion.
+	 * For request which hctx has only one ctx mapping,
+	 * or a polled request, always complete locally,
+	 * it's pointless to redirect the completion.
 	 */
-	if (rq->cmd_flags & REQ_POLLED)
+	if (rq->mq_hctx->nr_ctx == 1 ||
+		rq->cmd_flags & REQ_POLLED)
 		return false;
 
 	if (blk_mq_complete_need_ipi(rq)) {