summaryrefslogtreecommitdiff
path: root/mm/page-writeback.c
diff options
context:
space:
mode:
Diffstat (limited to 'mm/page-writeback.c')
-rw-r--r--mm/page-writeback.c11
1 files changed, 6 insertions, 5 deletions
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index fd51ebfc423f..6d0dbde4503b 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -1162,6 +1162,7 @@ static void wb_update_dirty_ratelimit(struct dirty_throttle_control *dtc,
unsigned long balanced_dirty_ratelimit;
unsigned long step;
unsigned long x;
+ unsigned long shift;
/*
* The dirty rate will match the writeout rate in long term, except
@@ -1286,11 +1287,11 @@ static void wb_update_dirty_ratelimit(struct dirty_throttle_control *dtc,
* rate itself is constantly fluctuating. So decrease the track speed
* when it gets close to the target. Helps eliminate pointless tremors.
*/
- step >>= dirty_ratelimit / (2 * step + 1);
- /*
- * Limit the tracking speed to avoid overshooting.
- */
- step = (step + 7) / 8;
+ shift = dirty_ratelimit / (2 * step + 1);
+ if (shift < BITS_PER_LONG)
+ step = DIV_ROUND_UP(step >> shift, 8);
+ else
+ step = 0;
if (dirty_ratelimit < balanced_dirty_ratelimit)
dirty_ratelimit += step;