Messages in this thread | | | From | "Wang, Wei W" <> | Subject | RE: [PATCH RFC] virtio_balloon: conservative balloon page shrinking | Date | Mon, 10 Feb 2020 03:13:21 +0000 |
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On Saturday, February 8, 2020 8:33 PM, Tetsuo Handa wrote: > > Is this NUMA aware? Can "node-A's NR_FILE_PAGES is already 0 and > node-B's NR_FILE_PAGES is not 0, but allocation request which triggered this > shrinker wants to allocate from only node-B" happen?
No, it's a global counter.
>Can some thread keep > this shrinker defunctional by keep increasing NR_FILE_PAGES?
Yes. Actually it's our intention - as long as there are pagecache pages, balloon pages are avoided to be reclaimed.
> > Is this patch from "Re: Balloon pressuring page cache" thread? I hope that > the guest could start reclaiming memory based on host's request (like OOM > notifier chain) which is issued when host thinks that host is getting close to > OOM and thus guests should start returning their unused memory to host. > Maybe "periodically (e.g. 5 minutes)" in addition to "upon close to OOM > condition" is also possible.
That's about the host usages. The host side management software decides when to issue a request to balloon (either periodically or event driven), I think there isn't anything we need to do in the balloon driver here.
Best, Wei
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