On Tue, Apr 28, 2020 at 12:44:43PM -0700, Matthew Wilcox wrote:
> From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
>
> x86 uses page->lru of the pages used for pgds, but that's not immediately
> obvious to anyone looking to make changes. Add a struct list_head to
> the union so it's clearly in use for pgds.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> ---
> include/linux/mm_types.h | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
> index 4aba6c0c2ba8..9bb34e2cd5a5 100644
> --- a/include/linux/mm_types.h
> +++ b/include/linux/mm_types.h
> @@ -142,8 +142,13 @@ struct page {
> struct list_head deferred_list;
> };
> struct { /* Page table pages */
> - unsigned long _pt_pad_1; /* compound_head */
> - pgtable_t pmd_huge_pte; /* protected by page->ptl */
> + union {
> + struct list_head pgd_list; /* x86 */
Shouldn't pgd_list_{add,del}() use this list head variable instead of lru to
complete the documentation?
Probably the list iteration loops arch/x86/* as well?
Ira
> + struct {
> + unsigned long _pt_pad_1;
> + pgtable_t pmd_huge_pte;
> + };
> + };
> unsigned long _pt_pad_2; /* mapping */
> union {
> struct mm_struct *pt_mm; /* x86 pgds only */
> --
> 2.26.2
>
>
