diff options
| author | Jan Engelmohr <jan.engelmohr@mailbox.tu-dresden.de> | 2016-07-26 18:11:29 +0200 |
|---|---|---|
| committer | Moyster <oysterized@gmail.com> | 2016-08-26 16:00:22 +0200 |
| commit | d668de80d065e7796d2fb31cf2c66084850baa2f (patch) | |
| tree | e44b4f602ca66eddfd3f884618501fb473214a0b /mm/page-writeback.c | |
| parent | 42fb8800204306978c6fb8f99ef68b8c1e895fd2 (diff) | |
3.10.74 -> 3.10.75
Diffstat (limited to 'mm/page-writeback.c')
| -rw-r--r-- | mm/page-writeback.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 8774051a2..a4e02d873 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -812,8 +812,11 @@ static void bdi_update_write_bandwidth(struct backing_dev_info *bdi, * bw * elapsed + write_bandwidth * (period - elapsed) * write_bandwidth = --------------------------------------------------- * period + * + * @written may have decreased due to account_page_redirty(). + * Avoid underflowing @bw calculation. */ - bw = written - bdi->written_stamp; + bw = written - min(written, bdi->written_stamp); bw *= HZ; if (unlikely(elapsed > period)) { do_div(bw, elapsed); @@ -877,7 +880,7 @@ static void global_update_bandwidth(unsigned long thresh, unsigned long now) { static DEFINE_SPINLOCK(dirty_lock); - static unsigned long update_time; + static unsigned long update_time = INITIAL_JIFFIES; /* * check locklessly first to optimize away locking for the most time |