Commit 81c7a63a authored by Yu Kuai's avatar Yu Kuai Committed by Jens Axboe
Browse files

blk-throttle: improve bypassing bios checkings 



"tg->has_rules" is extended to "tg->has_rules_iops/bps", thus bios that
don't need to be throttled can be checked accurately.

With this patch, bio will be throttled if:

1) Bio is read/write, and corresponding read/write iops limit exist.
2) If corresponding doesn't exist, corresponding bps limit exist and
bio is not throttled before.

Signed-off-by: default avatarYu Kuai <yukuai3@huawei.com>
Acked-by: default avatarTejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20220921095309.1481289-3-yukuai1@huaweicloud.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 85496749

block/blk-throttle.c

+9 −4
Original line number Diff line number Diff line
@@ -421,11 +421,16 @@ static void tg_update_has_rules(struct throtl_grp *tg) 
	struct throtl_data *td = tg->td;

	int rw;



	for (rw = READ; rw <= WRITE; rw++)

		tg->has_rules[rw] = (parent_tg && parent_tg->has_rules[rw]) ||

	for (rw = READ; rw <= WRITE; rw++) {

		tg->has_rules_iops[rw] =

			(parent_tg && parent_tg->has_rules_iops[rw]) ||

			(td->limit_valid[td->limit_index] &&

			 (tg_bps_limit(tg, rw) != U64_MAX ||

			  tg_iops_limit(tg, rw) != UINT_MAX));

			  tg_iops_limit(tg, rw) != UINT_MAX);

		tg->has_rules_bps[rw] =

			(parent_tg && parent_tg->has_rules_bps[rw]) ||

			(td->limit_valid[td->limit_index] &&

			 (tg_bps_limit(tg, rw) != U64_MAX));

	}

}



static void throtl_pd_online(struct blkg_policy_data *pd)

block/blk-throttle.h

+19 −3
Original line number Diff line number Diff line
@@ -98,7 +98,8 @@ struct throtl_grp { 
	unsigned int flags;



	/* are there any throtl rules between this group and td? */

	bool has_rules[2];

	bool has_rules_bps[2];

	bool has_rules_iops[2];



	/* internally used bytes per second rate limits */

	uint64_t bps[2][LIMIT_CNT];
@@ -178,11 +179,26 @@ void blk_throtl_exit(struct request_queue *q); 
void blk_throtl_register_queue(struct request_queue *q);

bool __blk_throtl_bio(struct bio *bio);

void blk_throtl_cancel_bios(struct request_queue *q);

static inline bool blk_throtl_bio(struct bio *bio)



static inline bool blk_should_throtl(struct bio *bio)

{

	struct throtl_grp *tg = blkg_to_tg(bio->bi_blkg);

	int rw = bio_data_dir(bio);



	/* iops limit is always counted */

	if (tg->has_rules_iops[rw])

		return true;



	if (tg->has_rules_bps[rw] && !bio_flagged(bio, BIO_BPS_THROTTLED))

		return true;



	return false;

}



static inline bool blk_throtl_bio(struct bio *bio)

{



	if (!tg->has_rules[bio_data_dir(bio)])

	if (!blk_should_throtl(bio))

		return false;



	return __blk_throtl_bio(bio);