diff options
Diffstat (limited to 'mm/page-writeback.c')
| -rw-r--r-- | mm/page-writeback.c | 75 |
1 files changed, 38 insertions, 37 deletions
diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 2cf69a5e46e..1ea13ef350a 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -267,10 +267,11 @@ static inline void task_dirties_fraction(struct task_struct *tsk, * * dirty -= (dirty/8) * p_{t} */ -static void task_dirty_limit(struct task_struct *tsk, unsigned long *pdirty) +static unsigned long task_dirty_limit(struct task_struct *tsk, + unsigned long bdi_dirty) { long numerator, denominator; - unsigned long dirty = *pdirty; + unsigned long dirty = bdi_dirty; u64 inv = dirty >> 3; task_dirties_fraction(tsk, &numerator, &denominator); @@ -278,10 +279,8 @@ static void task_dirty_limit(struct task_struct *tsk, unsigned long *pdirty) do_div(inv, denominator); dirty -= inv; - if (dirty < *pdirty/2) - dirty = *pdirty/2; - *pdirty = dirty; + return max(dirty, bdi_dirty/2); } /* @@ -391,9 +390,7 @@ unsigned long determine_dirtyable_memory(void) return x + 1; /* Ensure that we never return 0 */ } -void -get_dirty_limits(unsigned long *pbackground, unsigned long *pdirty, - unsigned long *pbdi_dirty, struct backing_dev_info *bdi) +void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty) { unsigned long background; unsigned long dirty; @@ -425,26 +422,28 @@ get_dirty_limits(unsigned long *pbackground, unsigned long *pdirty, } *pbackground = background; *pdirty = dirty; +} - if (bdi) { - u64 bdi_dirty; - long numerator, denominator; +unsigned long bdi_dirty_limit(struct backing_dev_info *bdi, + unsigned long dirty) +{ + u64 bdi_dirty; + long numerator, denominator; - /* - * Calculate this BDI's share of the dirty ratio. - */ - bdi_writeout_fraction(bdi, &numerator, &denominator); + /* + * Calculate this BDI's share of the dirty ratio. + */ + 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; - if (bdi_dirty > (dirty * bdi->max_ratio) / 100) - bdi_dirty = dirty * bdi->max_ratio / 100; + bdi_dirty = (dirty * (100 - bdi_min_ratio)) / 100; + bdi_dirty *= numerator; + do_div(bdi_dirty, denominator); - *pbdi_dirty = bdi_dirty; - task_dirty_limit(current, pbdi_dirty); - } + bdi_dirty += (dirty * bdi->min_ratio) / 100; + if (bdi_dirty > (dirty * bdi->max_ratio) / 100) + bdi_dirty = dirty * bdi->max_ratio / 100; + + return bdi_dirty; } /* @@ -475,13 +474,24 @@ static void balance_dirty_pages(struct address_space *mapping, .range_cyclic = 1, }; - get_dirty_limits(&background_thresh, &dirty_thresh, - &bdi_thresh, bdi); - nr_reclaimable = global_page_state(NR_FILE_DIRTY) + global_page_state(NR_UNSTABLE_NFS); nr_writeback = global_page_state(NR_WRITEBACK); + global_dirty_limits(&background_thresh, &dirty_thresh); + + /* + * Throttle it only when the background writeback cannot + * catch-up. This avoids (excessively) small writeouts + * when the bdi limits are ramping up. + */ + if (nr_reclaimable + nr_writeback < + (background_thresh + dirty_thresh) / 2) + break; + + bdi_thresh = bdi_dirty_limit(bdi, dirty_thresh); + bdi_thresh = task_dirty_limit(current, bdi_thresh); + /* * In order to avoid the stacked BDI deadlock we need * to ensure we accurately count the 'dirty' pages when @@ -513,15 +523,6 @@ static void balance_dirty_pages(struct address_space *mapping, if (!dirty_exceeded) break; - /* - * Throttle it only when the background writeback cannot - * catch-up. This avoids (excessively) small writeouts - * when the bdi limits are ramping up. - */ - if (nr_reclaimable + nr_writeback < - (background_thresh + dirty_thresh) / 2) - break; - if (!bdi->dirty_exceeded) bdi->dirty_exceeded = 1; @@ -634,7 +635,7 @@ void throttle_vm_writeout(gfp_t gfp_mask) unsigned long dirty_thresh; for ( ; ; ) { - get_dirty_limits(&background_thresh, &dirty_thresh, NULL, NULL); + global_dirty_limits(&background_thresh, &dirty_thresh); /* * Boost the allowable dirty threshold a bit for page |