Messages in this thread | | | Date | Wed, 12 Dec 2012 17:31:42 -0500 | From | Rik van Riel <> | Subject | Re: [patch 7/8] mm: vmscan: compaction works against zones, not lruvecs |
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On 12/12/2012 04:43 PM, Johannes Weiner wrote: > The restart logic for when reclaim operates back to back with > compaction is currently applied on the lruvec level. But this does > not make sense, because the container of interest for compaction is a > zone as a whole, not the zone pages that are part of a certain memory > cgroup. > > Negative impact is bounded. For one, the code checks that the lruvec > has enough reclaim candidates, so it does not risk getting stuck on a > condition that can not be fulfilled. And the unfairness of hammering > on one particular memory cgroup to make progress in a zone will be > amortized by the round robin manner in which reclaim goes through the > memory cgroups. Still, this can lead to unnecessary allocation > latencies when the code elects to restart on a hard to reclaim or > small group when there are other, more reclaimable groups in the zone. > > Move this logic to the zone level and restart reclaim for all memory > cgroups in a zone when compaction requires more free pages from it. > > Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
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