On Sun, Jul 09, 2017 at 11:05:44PM -0700, Ram Pai wrote: > On Mon, Jul 10, 2017 at 11:13:23AM +0530, Anshuman Khandual wrote: > > On 07/06/2017 02:51 AM, Ram Pai wrote: ..... > > > do you have data points to show the difference in > > performance between this version and the last one where > > we skipped the bits from PTE and directly programmed the > > HPTE entries looking into VMA bits. > > No. I dont. I am hoping you can help me out with this. Anshuman, The last version where we skipped the PTE bits is guaranteed to be bad/horrible. For one it has a bug, since it accesses the vma without a lock. And even if we did take a lock, it will slow down the page-hash path un-acceptably. So there is no point measuring the performance of that design. I think the number we want to measure is -- the performance with the current design and comparing that to the performance without memkey feature. We want to find if there is any degradation by adding this feature. RP
