On Mon, May 17, 2021 at 12:39:49PM -0700, Yang Shi wrote:

On Mon, May 17, 2021 at 8:09 AM Mel Gorman [off-list ref] wrote:

quoted

On Tue, Apr 13, 2021 at 02:24:10PM -0700, Yang Shi wrote:

quoted

Add orig_pmd to struct vm_fault so the "orig_pmd" parameter used by huge page
fault could be removed, just like its PTE counterpart does.

Signed-off-by: Yang Shi <redacted>

<SNIP>

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 25b9041f9925..9c5856f8cc81 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h

@@ -547,6 +547,9 @@ struct vm_fault {
                                       * the 'address'
                                       */
      pte_t orig_pte;                 /* Value of PTE at the time of fault */
+     pmd_t orig_pmd;                 /* Value of PMD at the time of fault,
+                                      * used by PMD fault only.
+                                      */

      struct page *cow_page;          /* Page handler may use for COW fault */
      struct page *page;              /* ->fault handlers should return a

Could this be a union?

Do you mean orig_pte and orig_pmd, or cow_page and page?

orig_pte and orig_pmd given that one for PTE faults and one is for PMD
faults and it's very unlikely they would both need to be considered during
a single fault.

-- 
Mel Gorman
SUSE Labs