On Wed, Apr 10, 2013 at 02:21:42PM +0900, Joonsoo Kim wrote:We are calling it fewer times but it's still receiving the same informationYes, but, with this patch, existing behaviour is changed, that is, we callPreserves existing behaviour.@@ -2673,9 +2674,15 @@ static bool kswapd_shrink_zone(struct zone *zone,Why shrink_slab() is called here?
sc->nr_to_reclaim = max(SWAP_CLUSTER_MAX, high_wmark_pages(zone));
shrink_zone(zone, sc);
- reclaim_state->reclaimed_slab = 0;
- nr_slab = shrink_slab(&shrink, sc->nr_scanned, lru_pages);
- sc->nr_reclaimed += reclaim_state->reclaimed_slab;
+ /*
+ * Slabs are shrunk for each zone once per priority or if the zone
+ * being balanced is otherwise unreclaimable
+ */
+ if (shrinking_slab || !zone_reclaimable(zone)) {
+ reclaim_state->reclaimed_slab = 0;
+ nr_slab = shrink_slab(&shrink, sc->nr_scanned, lru_pages);
+ sc->nr_reclaimed += reclaim_state->reclaimed_slab;
+ }
if (nr_slab == 0 && !zone_reclaimable(zone))
zone->all_unreclaimable = 1;
shrink_slab() once per priority. For now, there is no reason this function
is called here. How about separating it and executing it outside of
zone loop?
from sc->nr_scanned it received before. With the change you are suggesting
it would be necessary to accumulating sc->nr_scanned for each zone shrunk
and then pass the sum to shrink_slab() once per priority. While this is not
necessarily wrong, there is little or no motivation to alter the shrinkers
in this manner in this series.