On Wed, Nov 26, 2008 at 01:12:20PM +0200, Avi Kivity wrote: > Marcelo Tosatti wrote: >> >> Here it goes. >> >> KVM: MMU: optimize set_spte for page sync >> >> The write protect verification in set_spte is unnecessary for page sync. >> >> Its guaranteed that, if the unsync spte was writable, the target page >> does not have a write protected shadow (if it had, the spte would have >> been write protected under mmu_lock by rmap_write_protect before). >> >> Same reasoning applies to mark_page_dirty: the gfn has been marked as >> dirty via the pagefault path. >> >> The cost of hash table and memslot lookups are quite significant if the >> workload is pagetable write intensive resulting in increased mmu_lock >> contention. >> >> > > Applied, thanks.
Avi, Do you have objections for submitting this patch for 2.6.28 ? The hash lookup kills performance of pagetable write + context switch intensive workloads. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
