diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-08-25 23:30:23 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-08-25 23:30:23 +0300 |
commit | b8dcdab36f5394a09b66516057cccf61a81a3877 (patch) | |
tree | e08659de431a585acd3804464535334161e5a8cc /block/blk-wbt.c | |
parent | db84abf5f8075a739bfd73ddc432e6b8fe3ec4b6 (diff) | |
parent | c125311d96b1bfcce0f5930a4f0fdfe39ea14f7c (diff) |
Merge tag 'for-linus-20180825' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
"A few small fixes for this merge window:
- Locking imbalance fix for bcache (Shan Hai)
- A few small fixes for wbt. One is a cleanup/prep, one is a fix for
an existing issue, and the last two are fixes for changes that went
into this merge window (me)"
* tag 'for-linus-20180825' of git://git.kernel.dk/linux-block:
blk-wbt: don't maintain inflight counts if disabled
blk-wbt: fix has-sleeper queueing check
blk-wbt: use wq_has_sleeper() for wq active check
blk-wbt: move disable check into get_limit()
bcache: release dc->writeback_lock properly in bch_writeback_thread()
Diffstat (limited to 'block/blk-wbt.c')
-rw-r--r-- | block/blk-wbt.c | 37 |
1 files changed, 17 insertions, 20 deletions
diff --git a/block/blk-wbt.c b/block/blk-wbt.c index bb93c7c2b182..84507d3e9a98 100644 --- a/block/blk-wbt.c +++ b/block/blk-wbt.c @@ -118,7 +118,7 @@ static void rwb_wake_all(struct rq_wb *rwb) for (i = 0; i < WBT_NUM_RWQ; i++) { struct rq_wait *rqw = &rwb->rq_wait[i]; - if (waitqueue_active(&rqw->wait)) + if (wq_has_sleeper(&rqw->wait)) wake_up_all(&rqw->wait); } } @@ -162,7 +162,7 @@ static void __wbt_done(struct rq_qos *rqos, enum wbt_flags wb_acct) if (inflight && inflight >= limit) return; - if (waitqueue_active(&rqw->wait)) { + if (wq_has_sleeper(&rqw->wait)) { int diff = limit - inflight; if (!inflight || diff >= rwb->wb_background / 2) @@ -449,6 +449,13 @@ static inline unsigned int get_limit(struct rq_wb *rwb, unsigned long rw) { unsigned int limit; + /* + * If we got disabled, just return UINT_MAX. This ensures that + * we'll properly inc a new IO, and dec+wakeup at the end. + */ + if (!rwb_enabled(rwb)) + return UINT_MAX; + if ((rw & REQ_OP_MASK) == REQ_OP_DISCARD) return rwb->wb_background; @@ -485,31 +492,17 @@ static void __wbt_wait(struct rq_wb *rwb, enum wbt_flags wb_acct, { struct rq_wait *rqw = get_rq_wait(rwb, wb_acct); DECLARE_WAITQUEUE(wait, current); + bool has_sleeper; - /* - * inc it here even if disabled, since we'll dec it at completion. - * this only happens if the task was sleeping in __wbt_wait(), - * and someone turned it off at the same time. - */ - if (!rwb_enabled(rwb)) { - atomic_inc(&rqw->inflight); - return; - } - - if (!waitqueue_active(&rqw->wait) - && rq_wait_inc_below(rqw, get_limit(rwb, rw))) + has_sleeper = wq_has_sleeper(&rqw->wait); + if (!has_sleeper && rq_wait_inc_below(rqw, get_limit(rwb, rw))) return; add_wait_queue_exclusive(&rqw->wait, &wait); do { set_current_state(TASK_UNINTERRUPTIBLE); - if (!rwb_enabled(rwb)) { - atomic_inc(&rqw->inflight); - break; - } - - if (rq_wait_inc_below(rqw, get_limit(rwb, rw))) + if (!has_sleeper && rq_wait_inc_below(rqw, get_limit(rwb, rw))) break; if (lock) { @@ -518,6 +511,7 @@ static void __wbt_wait(struct rq_wb *rwb, enum wbt_flags wb_acct, spin_lock_irq(lock); } else io_schedule(); + has_sleeper = false; } while (1); __set_current_state(TASK_RUNNING); @@ -546,6 +540,9 @@ static enum wbt_flags bio_to_wbt_flags(struct rq_wb *rwb, struct bio *bio) { enum wbt_flags flags = 0; + if (!rwb_enabled(rwb)) + return 0; + if (bio_op(bio) == REQ_OP_READ) { flags = WBT_READ; } else if (wbt_should_throttle(rwb, bio)) { |