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. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
