nvme: implement mq_ops->commit_rqs() hook
fix #28871358 commit 04f3eafda6e05adc56afed4d3ae6e24aaa429058 upstream Split the command submission and the SQ doorbell ring, and add the doorbell ring as our ->commit_rqs() hook. This allows a list of requests to be issued, with nvme only writing the SQ update when it's necessary. This is more efficient if we have lists of requests to issue, particularly on virtualized hardware, where writing the SQ doorbell is more expensive than on real hardware. For those cases, performance increases of 2-3x have been observed. The use case for this is plugged IO, where blk-mq flushes a batch of requests at the time. Reviewed-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NJens Axboe <axboe@kernel.dk> Signed-off-by: NBaolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Showing
想要评论请 注册 或 登录