"Kirill A. Shutemov" <kirill@xxxxxxxxxxxxx> writes: > On Thu, Mar 23, 2017 at 01:55:27PM -0700, Mike Kravetz wrote: >> On 03/23/2017 05:58 AM, Punit Agrawal wrote: >> > On architectures that support hugepages composed of contiguous pte as >> > well as block entries at the same level in the page table, >> > huge_pte_offset() is not able to determine the right offset to return >> > when it encounters a swap entry (which is used to mark poisoned as >> > well as migrated pages in the page table). >> > >> > huge_pte_offset() needs to know the size of the hugepage at the >> > requested address to determine the offset to return - the current >> > entry or the first entry of a set of contiguous hugepages. This came >> > up while enabling support for memory failure handling on arm64[0]. >> > >> > Patch 1 adds a hstate parameter to huge_pte_offset() to provide >> > additional information about the target address. It also updates the >> > signatures (and usage) of huge_pte_offset() for architectures that >> > override the generic implementation. This patch has been compile >> > tested on ia64 and x86. >> >> I haven't looked at the performance implications of making huge_pte_offset >> just a little slower. But, I think you can get hstate from the parameters >> passed today. >> >> vma = find_vma(mm, addr); >> h = hstate_vma(vma); > > It's better to avoid find_vma() in fast(?) path if possible. So passing it > down is probably better. Also most call sites of huge_pte_offset() already have the hstate (or the vma) readily available. So adding overhead feels unnecessary. I agree that merging the patch will need some co-ordination but lets at the least give it a shot. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
