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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: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20211125133645.27483-3-jack@suse.cz
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jan Kara 2021-11-25 14:36:36 +01:00 committed by Jens Axboe
parent 98f044999b
commit 44dfa279f1
2 changed files with 7 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
block/bfq-iosched.c
View File

@ -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++)

1
block/bfq-iosched.h
View File

@ -769,6 +769,7 @@ struct bfq_data {
* function)
*/
unsigned int word_depths[2][2];
unsigned int full_depth_shift;
};
enum bfqq_state_flags {