On Wed, Apr 11, 2012 at 4:56 PM, Johannes Weiner <hannes@xxxxxxxxxxx> wrote: > On Wed, Apr 11, 2012 at 03:00:27PM -0700, Ying Han wrote: >> Under global background reclaim, the sc->nr_to_reclaim is set to >> ULONG_MAX. Now we are iterating all memcgs under the zone and we >> shouldn't pass the pressure from kswapd for each memcg. >> >> After all, the balance_pgdat() breaks after reclaiming SWAP_CLUSTER_MAX >> pages to prevent building up reclaim priorities. > > shrink_mem_cgroup_zone() bails out of a zone, balance_pgdat() bails > out of a priority loop, there is quite a difference. > > After this patch, kswapd no longer puts equal pressure on all zones in > the zonelist, which was a key reason why we could justify bailing > early out of individual zones in direct reclaim: kswapd will restore > fairness. Guess I see your point here. My intention is to prevent over-reclaim memcgs per-zone by having nr_to_reclaim to ULONG_MAX. Now, we scan each memcg based on get_scan_count() without bailout, do you see a problem w/o this patch? --Ying -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>