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block: don't try to throttle split bio if iops limit isn't set

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We need to throttle split bio in case of IOPS limit even though the
split bio has been marked as BIO_THROTTLED since block layer
accounts split bio actually.

If only throughput throttle is setup, no need to throttle any more
if BIO_THROTTLED is set since we have accounted & considered the
whole bio bytes already.

Add one flag of THROTL_TG_HAS_IOPS_LIMIT for serving this purpose.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20220216044514.2903784-8-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Ming Lei 2022-02-16 12:45:13 +08:00 committed by Jens Axboe
parent 9f5ede3c01
commit 5a93b6027e
2 changed files with 25 additions and 7 deletions
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21
block/blk-throttle.c
View File

@ -41,11 +41,6 @@
/* A workqueue to queue throttle related work */
static struct workqueue_struct *kthrotld_workqueue;
enum tg_state_flags {
THROTL_TG_PENDING = 1 << 0, /* on parent's pending tree */
THROTL_TG_WAS_EMPTY = 1 << 1, /* bio_lists[] became non-empty */
};
#define rb_entry_tg(node) rb_entry((node), struct throtl_grp, rb_node)
/* We measure latency for request size from <= 4k to >= 1M */
@ -425,12 +420,24 @@ static void tg_update_has_rules(struct throtl_grp *tg)
struct throtl_grp *parent_tg = sq_to_tg(tg->service_queue.parent_sq);
struct throtl_data *td = tg->td;
int rw;
int has_iops_limit = 0;
for (rw = READ; rw <= WRITE; rw++) {
unsigned int iops_limit = tg_iops_limit(tg, rw);
for (rw = READ; rw <= WRITE; rw++)
tg->has_rules[rw] = (parent_tg && parent_tg->has_rules[rw]) ||
(td->limit_valid[td->limit_index] &&
(tg_bps_limit(tg, rw) != U64_MAX ||
tg_iops_limit(tg, rw) != UINT_MAX));
iops_limit != UINT_MAX));
if (iops_limit != UINT_MAX)
has_iops_limit = 1;
}
if (has_iops_limit)
tg->flags |= THROTL_TG_HAS_IOPS_LIMIT;
else
tg->flags &= ~THROTL_TG_HAS_IOPS_LIMIT;
}
static void throtl_pd_online(struct blkg_policy_data *pd)

11
block/blk-throttle.h
View File

@ -52,6 +52,12 @@ struct throtl_service_queue {
struct timer_list pending_timer; /* fires on first_pending_disptime */
};
enum tg_state_flags {
THROTL_TG_PENDING = 1 << 0, /* on parent's pending tree */
THROTL_TG_WAS_EMPTY = 1 << 1, /* bio_lists[] became non-empty */
THROTL_TG_HAS_IOPS_LIMIT = 1 << 2, /* tg has iops limit */
};
enum {
LIMIT_LOW,
LIMIT_MAX,
@ -170,6 +176,11 @@ static inline bool blk_throtl_bio(struct bio *bio)
{
struct throtl_grp *tg = blkg_to_tg(bio->bi_blkg);
/* no need to throttle bps any more if the bio has been throttled */
if (bio_flagged(bio, BIO_THROTTLED) &&
!(tg->flags & THROTL_TG_HAS_IOPS_LIMIT))
return false;
if (!tg->has_rules[bio_data_dir(bio)])
return false;