Commit 48554df6 authored by Chengming Zhou's avatar Chengming Zhou Committed by Jens Axboe
Browse files

blk-mq: remove RQF_MQ_INFLIGHT 



Since the previous patch change to only account active requests when
we really allocate the driver tag, the RQF_MQ_INFLIGHT can be removed
and no double account problem.

1. none elevator: flush request will use the first pending request's
   driver tag, won't double account.

2. other elevator: flush request will be accounted when allocate driver
   tag when issue, and will be unaccounted when it put the driver tag.

Signed-off-by: default avatarChengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: default avatarMing Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230913151616.3164338-3-chengming.zhou@linux.dev


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent b8643d68

block/blk-flush.c

+2 −9
Original line number Diff line number Diff line
@@ -323,16 +323,9 @@ static void blk_kick_flush(struct request_queue *q, struct blk_flush_queue *fq, 
	flush_rq->mq_ctx = first_rq->mq_ctx;

	flush_rq->mq_hctx = first_rq->mq_hctx;



	if (!q->elevator) {

	if (!q->elevator)

		flush_rq->tag = first_rq->tag;



		/*

		 * We borrow data request's driver tag, so have to mark

		 * this flush request as INFLIGHT for avoiding double

		 * account of this driver tag

		 */

		flush_rq->rq_flags |= RQF_MQ_INFLIGHT;

	} else

	else

		flush_rq->internal_tag = first_rq->internal_tag;



	flush_rq->cmd_flags = REQ_OP_FLUSH | REQ_PREFLUSH;

block/blk-mq-debugfs.c

+0 −1
Original line number Diff line number Diff line
@@ -246,7 +246,6 @@ static const char *const rqf_name[] = { 
	RQF_NAME(STARTED),

	RQF_NAME(FLUSH_SEQ),

	RQF_NAME(MIXED_MERGE),

	RQF_NAME(MQ_INFLIGHT),

	RQF_NAME(DONTPREP),

	RQF_NAME(SCHED_TAGS),

	RQF_NAME(USE_SCHED),

block/blk-mq.c

+0 −4
Original line number Diff line number Diff line
@@ -1066,10 +1066,6 @@ static inline void blk_mq_flush_tag_batch(struct blk_mq_hw_ctx *hctx, 
{

	struct request_queue *q = hctx->queue;



	/*

	 * All requests should have been marked as RQF_MQ_INFLIGHT, so

	 * update hctx->nr_active in batch

	 */

	blk_mq_sub_active_requests(hctx, nr_tags);



	blk_mq_put_tags(hctx->tags, tag_array, nr_tags);

include/linux/blk-mq.h

+0 −2
Original line number Diff line number Diff line
@@ -32,8 +32,6 @@ typedef __u32 __bitwise req_flags_t; 
#define RQF_FLUSH_SEQ		((__force req_flags_t)(1 << 4))

/* merge of different types, fail separately */

#define RQF_MIXED_MERGE		((__force req_flags_t)(1 << 5))

/* track inflight for MQ */

#define RQF_MQ_INFLIGHT		((__force req_flags_t)(1 << 6))

/* don't call prep for this one */

#define RQF_DONTPREP		((__force req_flags_t)(1 << 7))

/* use hctx->sched_tags */