diff options
Diffstat (limited to 'block/blk-iocost.c')
| -rw-r--r-- | block/blk-iocost.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 089fcb9cfce3..04d44f0bcbc8 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -1261,7 +1261,7 @@ static void weight_updated(struct ioc_gq *iocg, struct ioc_now *now) static bool iocg_activate(struct ioc_gq *iocg, struct ioc_now *now) { struct ioc *ioc = iocg->ioc; - u64 last_period, cur_period; + u64 __maybe_unused last_period, cur_period; u64 vtime, vtarget; int i; @@ -1353,6 +1353,13 @@ static bool iocg_kick_delay(struct ioc_gq *iocg, struct ioc_now *now) lockdep_assert_held(&iocg->waitq.lock); + /* + * If the delay is set by another CPU, we may be in the past. No need to + * change anything if so. This avoids decay calculation underflow. + */ + if (time_before64(now->now, iocg->delay_at)) + return false; + /* calculate the current delay in effect - 1/2 every second */ tdelta = now->now - iocg->delay_at; if (iocg->delay) |