From: Kundan Kumar Date: Fri, 22 Dec 2023 10:17:07 +0000 (+0530) Subject: block: skip start/end time stamping for passthrough IO X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=8e6e83d77227d9ba39e0c7b50693f1b4f8728006;p=linux.git block: skip start/end time stamping for passthrough IO commit 41fa722239b4 ("blk-mq: do not include passthrough requests in I/O accounting")' disables I/O accounting for passthrough requests. Since tools like 'iostat' do not show anything useful for passthrough I/O, it's wasteful to do start/end time-stamping. So do away with that. Avoiding the time-stamping improves the I/O performance by ~7% Signed-off-by: Kundan Kumar Signed-off-by: Kanchan Joshi Link: https://lore.kernel.org/r/20231222101707.6921-1-kundan.kumar@samsung.com Signed-off-by: Jens Axboe --- diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 1ab3081c82eda..a676e116085f3 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -830,6 +830,12 @@ void blk_mq_end_request_batch(struct io_comp_batch *ib); */ static inline bool blk_mq_need_time_stamp(struct request *rq) { + /* + * passthrough io doesn't use iostat accounting, cgroup stats + * and io scheduler functionalities. + */ + if (blk_rq_is_passthrough(rq)) + return false; return (rq->rq_flags & (RQF_IO_STAT | RQF_STATS | RQF_USE_SCHED)); }