Re: [PATCH v2] blk-mq: check on cpu id when there is only one ctx mapping

From: Alexandre Mergnat
Date: Wed May 31 2023 - 05:40:18 EST


On 31/05/2023 10:38, Ed Tsai wrote:
commit f168420 ("blk-mq: don't redirect completion for hctx withs only
one ctx mapping") When nvme applies a 1:1 mapping of hctx and ctx, there
will be no remote request.

But for ufs, the submission and completion queues could be asymmetric.
(e.g. Multiple SQs share one CQ) Therefore, 1:1 mapping of hctx and
ctx won't complete request on the submission cpu. In this situation,
this nr_ctx check could violate the QUEUE_FLAG_SAME_FORCE, as a result,
check on cpu id when there is only one ctx mapping.

Reviewed-by: Alexandre Mergnat <amergnat@xxxxxxxxxxxx>

--
Regards,
Alexandre