Messages in this thread | | | Subject | Re: [PATCH] dax: Split pmd map when fallback on COW | From | Toshi Kani <> | Date | Mon, 23 Nov 2015 14:04:24 -0700 |
| |
On Mon, 2015-11-23 at 12:56 -0800, Dan Williams wrote: > On Mon, Nov 23, 2015 at 12:45 PM, Toshi Kani <toshi.kani@hpe.com> wrote: > > On Mon, 2015-11-23 at 12:45 -0800, Dan Williams wrote: > > > On Mon, Nov 23, 2015 at 12:05 PM, Toshi Kani <toshi.kani@hpe.com> wrote: > [..] > > > This is a nop if CONFIG_TRANSPARENT_HUGEPAGE=n, so I don't think it's > > > a complete fix. > > > > Well, __dax_pmd_fault() itself depends on CONFIG_TRANSPARENT_HUGEPAGE. > > > > Indeed it is... I think that's wrong because transparent huge pages > rely on struct page??
I do not think this issue is related with struct page. wp_huge_pmd() calls either do_huge_pmd_wp_page() or dax_pmd_fault(). do_huge_pmd_wp_page() splits a pmd page when it returns with VM_FAULT_FALLBACK. So, this change keeps them consistent on VM_FAULT_FALLBACK.
Thanks, -Toshi
| |