[PATCH v5 01/12] blk-mq: pass correct hctx to blk_mq_try_issue_directly
From: Ming Lei <hidden>
Date: 2017-06-06 15:22:36
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
When direct issue is done on request picked up from plug list, the hctx need to be updated with the actual hw queue, otherwise wrong hctx is used and may hurt performance, especially when wrong SRCU readlock is acquired/released Reported-by: Bart Van Assche <redacted> Signed-off-by: Ming Lei <redacted> --- block/blk-mq.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 58688205c8f4..c13888922e18 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c@@ -1558,9 +1558,12 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) blk_mq_put_ctx(data.ctx); - if (same_queue_rq) + if (same_queue_rq) { + data.hctx = blk_mq_map_queue(q, + same_queue_rq->mq_ctx->cpu); blk_mq_try_issue_directly(data.hctx, same_queue_rq, &cookie); + } } else if (q->nr_hw_queues > 1 && is_sync) { blk_mq_put_ctx(data.ctx); blk_mq_bio_to_request(rq, bio);
--
2.9.4