[PATCH V4 7/8] block: don't try to throttle split bio if iops limit isn't set
From: Ming Lei <hidden>
Date: 2022-02-16 04:46:58
Subsystem:
block layer, control group - block io controller (blkio), the rest · Maintainers:
Jens Axboe, Tejun Heo, Josef Bacik, Linus Torvalds
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 <redacted> --- block/blk-throttle.c | 21 ++++++++++++++------- block/blk-throttle.h | 11 +++++++++++ 2 files changed, 25 insertions(+), 7 deletions(-)
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index c7aa26d52e84..ec72eced24d2 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c@@ -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)
diff --git a/block/blk-throttle.h b/block/blk-throttle.h
index cb43f4417d6e..c996a15f290e 100644
--- a/block/blk-throttle.h
+++ b/block/blk-throttle.h@@ -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;
--
2.31.1