Commit 34841e6f authored by Ming Lei's avatar Ming Lei Committed by Jens Axboe
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block: revert 4f1e9630 ("blk-throtl: optimize IOPS throttle for large IO scenarios") 



Revert commit 4f1e9630 ("blk-throtl: optimize IOPS throttle for large
IO scenarios") since we have another easier way to address this issue and
get better iops throttling result.

Acked-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20220216044514.2903784-9-ming.lei@redhat.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 5a93b602

block/blk-throttle.c

+0 −28
Original line number Diff line number Diff line
@@ -640,8 +640,6 @@ static inline void throtl_start_new_slice_with_credit(struct throtl_grp *tg, 
	tg->bytes_disp[rw] = 0;

	tg->io_disp[rw] = 0;



	atomic_set(&tg->io_split_cnt[rw], 0);



	/*

	 * Previous slice has expired. We must have trimmed it after last

	 * bio dispatch. That means since start of last slice, we never used
@@ -665,8 +663,6 @@ static inline void throtl_start_new_slice(struct throtl_grp *tg, bool rw) 
	tg->slice_start[rw] = jiffies;

	tg->slice_end[rw] = jiffies + tg->td->throtl_slice;



	atomic_set(&tg->io_split_cnt[rw], 0);



	throtl_log(&tg->service_queue,

		   "[%c] new slice start=%lu end=%lu jiffies=%lu",

		   rw == READ ? 'R' : 'W', tg->slice_start[rw],
@@ -900,9 +896,6 @@ static bool tg_may_dispatch(struct throtl_grp *tg, struct bio *bio, 
				jiffies + tg->td->throtl_slice);

	}



	if (iops_limit != UINT_MAX)

		tg->io_disp[rw] += atomic_xchg(&tg->io_split_cnt[rw], 0);



	if (tg_with_in_bps_limit(tg, bio, bps_limit, &bps_wait) &&

	    tg_with_in_iops_limit(tg, bio, iops_limit, &iops_wait)) {

		if (wait)
@@ -1927,14 +1920,12 @@ static void throtl_downgrade_check(struct throtl_grp *tg) 
	}



	if (tg->iops[READ][LIMIT_LOW]) {

		tg->last_io_disp[READ] += atomic_xchg(&tg->last_io_split_cnt[READ], 0);

		iops = tg->last_io_disp[READ] * HZ / elapsed_time;

		if (iops >= tg->iops[READ][LIMIT_LOW])

			tg->last_low_overflow_time[READ] = now;

	}



	if (tg->iops[WRITE][LIMIT_LOW]) {

		tg->last_io_disp[WRITE] += atomic_xchg(&tg->last_io_split_cnt[WRITE], 0);

		iops = tg->last_io_disp[WRITE] * HZ / elapsed_time;

		if (iops >= tg->iops[WRITE][LIMIT_LOW])

			tg->last_low_overflow_time[WRITE] = now;
@@ -2053,25 +2044,6 @@ static inline void throtl_update_latency_buckets(struct throtl_data *td) 
}

#endif



void blk_throtl_charge_bio_split(struct bio *bio)

{

	struct blkcg_gq *blkg = bio->bi_blkg;

	struct throtl_grp *parent = blkg_to_tg(blkg);

	struct throtl_service_queue *parent_sq;

	bool rw = bio_data_dir(bio);



	do {

		if (!parent->has_rules[rw])

			break;



		atomic_inc(&parent->io_split_cnt[rw]);

		atomic_inc(&parent->last_io_split_cnt[rw]);



		parent_sq = parent->service_queue.parent_sq;

		parent = sq_to_tg(parent_sq);

	} while (parent);

}



bool __blk_throtl_bio(struct bio *bio)

{

	struct request_queue *q = bdev_get_queue(bio->bi_bdev);

block/blk-throttle.h

+0 −5
Original line number Diff line number Diff line
@@ -138,9 +138,6 @@ struct throtl_grp { 
	unsigned int bad_bio_cnt; /* bios exceeding latency threshold */

	unsigned long bio_cnt_reset_time;



	atomic_t io_split_cnt[2];

	atomic_t last_io_split_cnt[2];



	struct blkg_rwstat stat_bytes;

	struct blkg_rwstat stat_ios;

};
@@ -164,13 +161,11 @@ static inline struct throtl_grp *blkg_to_tg(struct blkcg_gq *blkg) 
static inline int blk_throtl_init(struct request_queue *q) { return 0; }

static inline void blk_throtl_exit(struct request_queue *q) { }

static inline void blk_throtl_register_queue(struct request_queue *q) { }

static inline void blk_throtl_charge_bio_split(struct bio *bio) { }

static inline bool blk_throtl_bio(struct bio *bio) { return false; }

#else /* CONFIG_BLK_DEV_THROTTLING */

int blk_throtl_init(struct request_queue *q);

void blk_throtl_exit(struct request_queue *q);

void blk_throtl_register_queue(struct request_queue *q);

void blk_throtl_charge_bio_split(struct bio *bio);

bool __blk_throtl_bio(struct bio *bio);

static inline bool blk_throtl_bio(struct bio *bio)

{