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>
This commit is contained in:
Liu Song 2022-09-21 11:32:03 +08:00 committed by Jens Axboe
parent 81c7a63abc
commit f168420c62

View File

@ -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)) {