Messages in this thread | | | Date | Tue, 13 Apr 2010 12:01:37 -0300 | From | Marcelo Tosatti <> | Subject | Re: [PATCH 3/6] KVM MMU: optimize/cleanup for marking parent unsync |
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On Tue, Apr 13, 2010 at 09:53:07AM +0800, Xiao Guangrong wrote: > > > Marcelo Tosatti wrote: > > > Xiao, > > > > Did you actually see this codepath as being performance sensitive? > > Actually, i not run benchmarks to contrast the performance before this patch > and after this patch. > > > > > I'd prefer to not touch it. > > This patch avoids walk all parents and i think this overload is really unnecessary. > It has other tricks in this codepath but i not noticed? :-)
My point is that there is no point in optimizing something unless its performance sensitive. And as i recall, mmu_unsync_walk was much more sensitive performance wise than parent walking. Actually, gfn_to_memslot seems more important since its also noticeable on EPT/NPT hosts.
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