Messages in this thread | | | Date | Tue, 17 Apr 2012 14:26:49 +0800 | From | Xiao Guangrong <> | Subject | Re: [PATCH 00/13] KVM: MMU: fast page fault |
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On 04/16/2012 11:49 PM, Takuya Yoshikawa wrote:
> Although O(1) is actually O(1) for GET_DIRTY_LOG thread, it adds some > overheads to page fault handling. We may need to hold mmu_lock for properly > handling O(1)'s write protection and ~500 write protections will not be so > cheap. And there is no answer to the question how to achive slot-wise write > protection. >
Actually no.
We do not increase the overload on page fault for migration. The number of page fault of O(1) is the same as write-protect all spte.
And, we can also avoid to hold mmu_lock to write-protect PML4s, we can use a generation number, and notify mmu to update its page table when dirty-log is enabled.
Anyway, no performance data, no truth. Let me implement it first.
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