On Tue, Jun 20, 2017 at 04:21:45PM +0530, Anshuman Khandual wrote: > On 06/17/2017 09:22 AM, Ram Pai wrote: > > Rearrange 64K PTE bits to free up bits 3, 4, 5 and 6 > > in the 64K backed hpte pages. This along with the earlier > > patch will entirely free up the four bits from 64K PTE. > > > > This patch does the following change to 64K PTE that is > > backed by 64K hpte. > > > > H_PAGE_F_SECOND which occupied bit 4 moves to the second part > > of the pte. > > H_PAGE_F_GIX which occupied bit 5, 6 and 7 also moves to the > > second part of the pte. > > > > since bit 7 is now freed up, we move H_PAGE_BUSY from bit 9 > > to bit 7. Trying to minimize gaps so that contiguous bits > > can be allocated if needed in the future. > > > > The second part of the PTE will hold > > (H_PAGE_F_SECOND|H_PAGE_F_GIX) at bit 60,61,62,63. > > I still dont understand how we freed up the 5th bit which is > used in the 5th patch. Was that bit never used for any thing > on 64K page size (64K and 4K mappings) ?
yes. it was not used. So I gladly used it :-) RP
