diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/backing-dev.c | 5 | ||||
| -rw-r--r-- | mm/page-writeback.c | 10 |
2 files changed, 7 insertions, 8 deletions
diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 161ddf12b862..d2f16fc9069a 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -256,11 +256,6 @@ static int __init default_bdi_init(void) } subsys_initcall(default_bdi_init); -bool bdi_has_dirty_io(struct backing_dev_info *bdi) -{ - return wb_has_dirty_io(&bdi->wb); -} - /* * This function is used when the first inode for this wb is marked dirty. It * wakes-up the corresponding bdi thread which should then take care of the diff --git a/mm/page-writeback.c b/mm/page-writeback.c index c95eb24dd652..99b88465096e 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -881,9 +881,13 @@ static void wb_update_write_bandwidth(struct bdi_writeback *wb, avg += (old - avg) >> 3; out: - if (wb_has_dirty_io(wb)) - atomic_long_add(avg - wb->avg_write_bandwidth, - &wb->bdi->tot_write_bandwidth); + /* keep avg > 0 to guarantee that tot > 0 if there are dirty wbs */ + avg = max(avg, 1LU); + if (wb_has_dirty_io(wb)) { + long delta = avg - wb->avg_write_bandwidth; + WARN_ON_ONCE(atomic_long_add_return(delta, + &wb->bdi->tot_write_bandwidth) <= 0); + } wb->write_bandwidth = bw; wb->avg_write_bandwidth = avg; } |