On Thu, Sep 14, 2017 at 06:13:57PM +1000, Benjamin Herrenschmidt wrote: > On Fri, 2017-09-08 at 15:44 -0700, Ram Pai wrote: > > The second part of the PTE will hold > > (H_PAGE_F_SECOND|H_PAGE_F_GIX) at bit 60,61,62,63. > > NOTE: None of the bits in the secondary PTE were not used > > by 64k-HPTE backed PTE. > > Have you measured the performance impact of this ? The second part of > the PTE being in a different cache line there could be one...
hmm..missed responding to this comment. I did a preliminay measurement running mmap bench in the selftest. Ran it multiple times. almost always the numbers were either equal-to or better-than without the patch-series. RP
