diff options
Diffstat (limited to 'mm/page-writeback.c')
| -rw-r--r-- | mm/page-writeback.c | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/mm/page-writeback.c b/mm/page-writeback.c index e5b6b1190a9..4ac077f4269 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -243,6 +243,29 @@ static void task_dirty_limit(struct task_struct *tsk, long *pdirty) } /* + * + */ +static DEFINE_SPINLOCK(bdi_lock); +static unsigned int bdi_min_ratio; + +int bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_ratio) +{ + int ret = 0; + unsigned long flags; + + spin_lock_irqsave(&bdi_lock, flags); + min_ratio -= bdi->min_ratio; + if (bdi_min_ratio + min_ratio < 100) { + bdi_min_ratio += min_ratio; + bdi->min_ratio += min_ratio; + } else + ret = -EINVAL; + spin_unlock_irqrestore(&bdi_lock, flags); + + return ret; +} + +/* * Work out the current dirty-memory clamping and background writeout * thresholds. * @@ -330,7 +353,7 @@ get_dirty_limits(long *pbackground, long *pdirty, long *pbdi_dirty, *pdirty = dirty; if (bdi) { - u64 bdi_dirty = dirty; + u64 bdi_dirty; long numerator, denominator; /* @@ -338,8 +361,10 @@ get_dirty_limits(long *pbackground, long *pdirty, long *pbdi_dirty, */ bdi_writeout_fraction(bdi, &numerator, &denominator); + bdi_dirty = (dirty * (100 - bdi_min_ratio)) / 100; bdi_dirty *= numerator; do_div(bdi_dirty, denominator); + bdi_dirty += (dirty * bdi->min_ratio) / 100; *pbdi_dirty = bdi_dirty; clip_bdi_dirty_limit(bdi, dirty, pbdi_dirty); |