Messages in this thread | | | Date | Thu, 13 Dec 2012 14:33:32 -0500 | From | Johannes Weiner <> | Subject | Re: [patch 3/8] mm: vmscan: save work scanning (almost) empty LRU lists |
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On Thu, Dec 13, 2012 at 10:41:04AM +0000, Mel Gorman wrote: > On Wed, Dec 12, 2012 at 04:43:35PM -0500, Johannes Weiner wrote: > > In certain cases (kswapd reclaim, memcg target reclaim), a fixed > > minimum amount of pages is scanned from the LRU lists on each > > iteration, to make progress. > > > > Do not make this minimum bigger than the respective LRU list size, > > however, and save some busy work trying to isolate and reclaim pages > > that are not there. > > > > Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> > > This looks like a corner case where the LRU size would have to be smaller > than SWAP_CLUSTER_MAX. Is that common enough to care? It looks correct, > I'm just curious.
We have one lruvec per memcg per zone, so consider memory cgroups in a NUMA environment: NR_MEMCG * (NR_NODES - 1) * NR_LRU_LISTS permanently empty lruvecs, assuming the memory of one cgroup is bound to one node.
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