Re: [RFC PATCH v1 3/5] KVM: Add paravirt kvm_flush_tlb_others

From: Peter Zijlstra
Date: Tue May 01 2012 - 11:12:11 EST


On Tue, 2012-05-01 at 15:12 +0300, Avi Kivity wrote:
> We're now moving the freeing of kvm shadow page tables from using rcu to
> using an irq-protected scheme like gup_fast(), because of the
> performance differences. We didn't track it down but I expect the cause
> is less reuse of cache-hot pages.

It would be good to understand these things.. just doing things because
tends to come back and bite you :-)

If its cache behaviour you should be able to clearly see that using perf
stat.
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