Re: [PATCH v2] kvm/x86: Inform RCU of quiescent state when entering guest mode

David Woodhouse
2018-07-12T09:53:05Z

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On Thu, 2018-07-12 at 08:21 +0200, Christian Borntraeger wrote:
>
> Is there a single patch that that I can test or do I have to combine
> all the pieces that are sprinkled in this mail thread?

I believe it should be just these two commits, and the first is
probably optional as the second makes it mostly redundant for the KVM
case. Fengguang's 0day bot is watching this tree, so I expect to get
success/failure results fairly shortly for various build tests at
least.

http://git.infradead.org/users/dwmw2/random-2.6.git/shortlog/refs/heads/kvm-rcu

As noted, the first (need_resched) patch took our observed
RCU latencies down from 5-10 seconds to 160ms, while the second one
that we're working on now took it down to 40ms.

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