Messages in this thread | | | Date | Mon, 8 Feb 2016 15:43:11 -0500 | From | Johannes Weiner <> | Subject | Re: [PATCH 5/5] mm: workingset: make shadow node shrinker memcg aware |
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On Mon, Feb 08, 2016 at 05:28:35PM +0300, Vladimir Davydov wrote: > On Mon, Feb 08, 2016 at 01:23:53AM -0500, Johannes Weiner wrote: > > It's true that both the shrinking of the active list and subsequent > > activations to regrow it will reduce the number of actionable > > refaults, and so it wouldn't be unreasonable to also shrink shadow > > nodes when the active list shrinks. > > > > However, I think these are too many assumptions to encode in the > > shrinker, because it is only meant to prevent a worst-case explosion > > of radix tree nodes. I'd prefer it to be dumb and conservative. > > > > Could we instead go with the current usage of the memcg? Whether > > reclaim happens globally or due to the memory limit, the usage at the > > time of reclaim gives a good idea of the memory is available to the > > group. But it's making less assumptions about the internal composition > > of the memcg's memory, and the consequences associated with that. > > But that would likely result in wasting a considerable chunk of memory > for stale shadow nodes in case file caches constitute only a small part > of memcg memory consumption, which isn't good IMHO.
Hm, that's probably true. But I think it's a separate patch at this point - going from total memory to the cache portion for overhead reasons - that shouldn't be conflated with the memcg awareness patch.
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