diff options
| -rw-r--r-- | mm/vmscan.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index cb8ad3c6e48..bbd194630c5 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -932,6 +932,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone, long mapped_ratio; long distress; long swap_tendency; + long imbalance; if (zone_is_near_oom(zone)) goto force_reclaim_mapped; @@ -967,6 +968,46 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone, swap_tendency = mapped_ratio / 2 + distress + sc->swappiness; /* + * If there's huge imbalance between active and inactive + * (think active 100 times larger than inactive) we should + * become more permissive, or the system will take too much + * cpu before it start swapping during memory pressure. + * Distress is about avoiding early-oom, this is about + * making swappiness graceful despite setting it to low + * values. + * + * Avoid div by zero with nr_inactive+1, and max resulting + * value is vm_total_pages. + */ + imbalance = zone_page_state(zone, NR_ACTIVE); + imbalance /= zone_page_state(zone, NR_INACTIVE) + 1; + + /* + * Reduce the effect of imbalance if swappiness is low, + * this means for a swappiness very low, the imbalance + * must be much higher than 100 for this logic to make + * the difference. + * + * Max temporary value is vm_total_pages*100. + */ + imbalance *= (vm_swappiness + 1); + imbalance /= 100; + + /* + * If not much of the ram is mapped, makes the imbalance + * less relevant, it's high priority we refill the inactive + * list with mapped pages only in presence of high ratio of + * mapped pages. + * + * Max temporary value is vm_total_pages*100. + */ + imbalance *= mapped_ratio; + imbalance /= 100; + + /* apply imbalance feedback to swap_tendency */ + swap_tendency += imbalance; + + /* * Now use this metric to decide whether to start moving mapped * memory onto the inactive list. */ |