diff options
Diffstat (limited to 'block/blk-cgroup.c')
| -rw-r--r-- | block/blk-cgroup.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 83930f6..af42efb 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -213,7 +213,7 @@ void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg) } EXPORT_SYMBOL_GPL(blkiocg_update_avg_queue_size_stats); -void blkiocg_set_start_empty_time(struct blkio_group *blkg, bool ignore) +void blkiocg_set_start_empty_time(struct blkio_group *blkg) { unsigned long flags; struct blkio_group_stats *stats; @@ -228,12 +228,15 @@ void blkiocg_set_start_empty_time(struct blkio_group *blkg, bool ignore) } /* - * If ignore is set, we do not panic on the empty flag being set - * already. This is to avoid cases where there are superfluous timeslice - * complete events (for eg., forced_dispatch in CFQ) when no IOs are - * served which could result in triggering the empty check incorrectly. + * group is already marked empty. This can happen if cfqq got new + * request in parent group and moved to this group while being added + * to service tree. Just ignore the event and move on. */ - BUG_ON(!ignore && blkio_blkg_empty(stats)); + if(blkio_blkg_empty(stats)) { + spin_unlock_irqrestore(&blkg->stats_lock, flags); + return; + } + stats->start_empty_time = sched_clock(); blkio_mark_blkg_empty(stats); spin_unlock_irqrestore(&blkg->stats_lock, flags); |