Marcelo Tosatti wrote: > On Thu, Feb 21, 2008 at 08:30:04PM +0200, Avi Kivity wrote: > >>> Perhaps you want to move that enforcement to the host. >>> >>> This allows batching of future hypercalls (if appropriate) to be easy. >>> >>> >>> >> I'm still uneasy about it, though I have no rational reasons left now. >> >> Oh, there is one: with a MMU_OP hypercall you can take the mmu spinlock >> once per batch (dropping it once in a while to let another vcpu make >> progress or to inject an interrupt). >> > > emulator_write_phys() needs to do blocking work for each pte > (mmu_guess_page_from_pte), so that optimization would need quite some > work (separate mmu_guess_page_from_pte from kvm_mmu_pte_write). > > And you can do this optimization even without MMU_OP, just check in > advance how many operations will take the mmu lock, do the non-blocking > part of them, and then manipulate the mmu lock protected shadow data. > > Also, holding the spinlock for a longer period is not necessarily an > improvement (with the slots_lock it clearly is because there is no write > contention). > >
Yes, you are right. -- Do not meddle in the internals of kernels, for they are subtle and quick to panic. ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
