Messages in this thread | | | Date | Mon, 24 Sep 2012 19:49:37 +0800 | From | Xiao Guangrong <> | Subject | Re: [PATCH v3 1/7] KVM: MMU: fix release noslot pfn |
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On 09/24/2012 07:24 PM, Gleb Natapov wrote: > On Mon, Sep 24, 2012 at 12:59:32PM +0800, Xiao Guangrong wrote: >> On 09/23/2012 05:13 PM, Gleb Natapov wrote: >>> On Fri, Sep 21, 2012 at 02:57:19PM +0800, Xiao Guangrong wrote: >>>> We can not directly call kvm_release_pfn_clean to release the pfn >>>> since we can meet noslot pfn which is used to cache mmio info into >>>> spte >>>> >>> Wouldn't it be better to move the check into kvm_release_pfn_clean()? >> >> I think there is no reason for us to prefer to adding this branch in >> the common code. :) > > Is the function performance critical? Is function called without the check > on a hot path? The function already contains much heavier kvm_is_mmio_pfn() > check. If most/all function invocation require check before call it's > better to move it inside.
It is not most/all functions need do this check - it is only needed on x86 mmu page-fault/prefetch path.
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