From 5a93b6027eb4ef5db60a4bc5bdbeba5fb9f29384 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Wed, 16 Feb 2022 12:45:13 +0800 Subject: [PATCH] block: don't try to throttle split bio if iops limit isn't set 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 Signed-off-by: Ming Lei Link: https://lore.kernel.org/r/20220216044514.2903784-8-ming.lei@redhat.com Signed-off-by: Jens Axboe --- 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 c7aa26d..ec72ece 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 cb43f44..c996a15 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; -- 2.7.4