Commit 44dfa279 authored by Jan Kara's avatar Jan Kara Committed by Jens Axboe
Browse files

bfq: Store full bitmap depth in bfq_data 



Store bitmap depth shift inside bfq_data so that we can use it in
bfq_limit_depth() for proportioning when limiting number of available
request tags for a cgroup.

Acked-by: default avatarPaolo Valente <paolo.valente@linaro.org>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20211125133645.27483-3-jack@suse.cz


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 98f04499

block/bfq-iosched.c

+6 −4
Original line number Diff line number Diff line
@@ -6857,7 +6857,9 @@ static unsigned int bfq_update_depths(struct bfq_data *bfqd, 
				      struct sbitmap_queue *bt)

{

	unsigned int i, j, min_shallow = UINT_MAX;

	unsigned int depth = 1U << bt->sb.shift;



	bfqd->full_depth_shift = bt->sb.shift;

	/*

	 * In-word depths if no bfq_queue is being weight-raised:

	 * leaving 25% of tags only for sync reads.
@@ -6869,13 +6871,13 @@ static unsigned int bfq_update_depths(struct bfq_data *bfqd, 
	 * limit 'something'.

	 */

	/* no more than 50% of tags for async I/O */

	bfqd->word_depths[0][0] = max((1U << bt->sb.shift) >> 1, 1U);

	bfqd->word_depths[0][0] = max(depth >> 1, 1U);

	/*

	 * no more than 75% of tags for sync writes (25% extra tags

	 * w.r.t. async I/O, to prevent async I/O from starving sync

	 * writes)

	 */

	bfqd->word_depths[0][1] = max(((1U << bt->sb.shift) * 3) >> 2, 1U);

	bfqd->word_depths[0][1] = max((depth * 3) >> 2, 1U);



	/*

	 * In-word depths in case some bfq_queue is being weight-
@@ -6885,9 +6887,9 @@ static unsigned int bfq_update_depths(struct bfq_data *bfqd, 
	 * shortage.

	 */

	/* no more than ~18% of tags for async I/O */

	bfqd->word_depths[1][0] = max(((1U << bt->sb.shift) * 3) >> 4, 1U);

	bfqd->word_depths[1][0] = max((depth * 3) >> 4, 1U);

	/* no more than ~37% of tags for sync writes (~20% extra tags) */

	bfqd->word_depths[1][1] = max(((1U << bt->sb.shift) * 6) >> 4, 1U);

	bfqd->word_depths[1][1] = max((depth * 6) >> 4, 1U);



	for (i = 0; i < 2; i++)

		for (j = 0; j < 2; j++)

block/bfq-iosched.h

+1 −0
Original line number Diff line number Diff line
@@ -769,6 +769,7 @@ struct bfq_data { 
	 * function)

	 */

	unsigned int word_depths[2][2];

	unsigned int full_depth_shift;

};



enum bfqq_state_flags {