diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 0713bfbf09541..1534ebd6e70f5 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -692,7 +692,7 @@ static unsigned long bdi_position_ratio(struct backing_dev_info *bdi, * => fast response on large errors; small oscillation near setpoint */ setpoint = (freerun + limit) / 2; - x = div_s64((setpoint - dirty) << RATELIMIT_CALC_SHIFT, + x = div_s64(((s64)setpoint - (s64)dirty) << RATELIMIT_CALC_SHIFT, limit - setpoint + 1); pos_ratio = x; pos_ratio = pos_ratio * x >> RATELIMIT_CALC_SHIFT;