blk-throttle: remove THROTL_TG_HAS_IOPS_LIMIT

Currently, "tg->has_rules" and "tg->flags & THROTL_TG_HAS_IOPS_LIMIT"
both try to bypass bios that don't need to be throttled, however, they are
a little redundant and both not perfect:

1) "tg->has_rules" only distinguish read and write, but not iops and bps
   limit.
2) "tg->flags & THROTL_TG_HAS_IOPS_LIMIT" only check if iops limit
   exist, read and write is not distinguished, and bps limit is not
   checked.

tg->has_rules will extended to distinguish bps and iops in the following
patch. There is no need to keep the flag.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20220921095309.1481289-2-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Yu Kuai 2022-09-21 17:53:08 +08:00 committed by Jens Axboe
parent c732a852b4
commit 8549674990
2 changed files with 3 additions and 21 deletions

View File

@ -420,24 +420,12 @@ 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 ||
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;
tg_iops_limit(tg, rw) != UINT_MAX));
}
static void throtl_pd_online(struct blkg_policy_data *pd)

View File

@ -55,8 +55,7 @@ struct throtl_service_queue {
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 */
THROTL_TG_CANCELING = 1 << 3, /* starts to cancel bio */
THROTL_TG_CANCELING = 1 << 2, /* starts to cancel bio */
};
enum {
@ -183,11 +182,6 @@ 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_BPS_THROTTLED) &&
!(tg->flags & THROTL_TG_HAS_IOPS_LIMIT))
return false;
if (!tg->has_rules[bio_data_dir(bio)])
return false;