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| author | Yu Kuai <yukuai3@huawei.com> | 2024-05-09 15:11:07 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2024-05-09 18:44:56 +0300 |
| commit | a3166c51702bb00b8f8b84022090cbab8f37be1a (patch) | |
| tree | dc0f7d08dc8dc0438a578f96809658ff97016c5f /block/blk-throttle.h | |
| parent | bf20ab538c81bb32edab86f503fc0c55d8243bbc (diff) | |
| download | linux-a3166c51702bb00b8f8b84022090cbab8f37be1a.tar.xz | |
blk-throttle: delay initialization until configuration
Other cgroup policy like bfq, iocost are lazy-initialized when they are
configured for the first time for the device, but blk-throttle is
initialized unconditionally from blkcg_init_disk().
Delay initialization of blk-throttle as well, to save some cpu and
memory overhead if it's not configured.
Noted that once it's initialized, it can't be destroyed until disk
removal, even if it's disabled.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240509121107.3195568-3-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-throttle.h')
| -rw-r--r-- | block/blk-throttle.h | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/block/blk-throttle.h b/block/blk-throttle.h index 32503fd83a84..393c3d134b96 100644 --- a/block/blk-throttle.h +++ b/block/blk-throttle.h @@ -150,23 +150,33 @@ static inline struct throtl_grp *blkg_to_tg(struct blkcg_gq *blkg) * Internal throttling interface */ #ifndef CONFIG_BLK_DEV_THROTTLING -static inline int blk_throtl_init(struct gendisk *disk) { return 0; } static inline void blk_throtl_exit(struct gendisk *disk) { } -static inline void blk_throtl_register(struct gendisk *disk) { } static inline bool blk_throtl_bio(struct bio *bio) { return false; } static inline void blk_throtl_cancel_bios(struct gendisk *disk) { } #else /* CONFIG_BLK_DEV_THROTTLING */ -int blk_throtl_init(struct gendisk *disk); void blk_throtl_exit(struct gendisk *disk); -void blk_throtl_register(struct gendisk *disk); bool __blk_throtl_bio(struct bio *bio); void blk_throtl_cancel_bios(struct gendisk *disk); +static inline bool blk_throtl_activated(struct request_queue *q) +{ + return q->td != NULL; +} + static inline bool blk_should_throtl(struct bio *bio) { - struct throtl_grp *tg = blkg_to_tg(bio->bi_blkg); + struct throtl_grp *tg; int rw = bio_data_dir(bio); + /* + * This is called under bio_queue_enter(), and it's synchronized with + * the activation of blk-throtl, which is protected by + * blk_mq_freeze_queue(). + */ + if (!blk_throtl_activated(bio->bi_bdev->bd_queue)) + return false; + + tg = blkg_to_tg(bio->bi_blkg); if (!cgroup_subsys_on_dfl(io_cgrp_subsys)) { if (!bio_flagged(bio, BIO_CGROUP_ACCT)) { bio_set_flag(bio, BIO_CGROUP_ACCT); |