From a052f0a5168ef99c517f6638aaec59f39060f81d Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Thu, 7 Jun 2018 17:08:57 -0700 Subject: [PATCH] mm: add pt_mm to struct page MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit For pgd page table pages, x86 overloads the page->index field to store a pointer to the mm_struct. Rename this to pt_mm so it's visible to other users. Link: http://lkml.kernel.org/r/20180518194519.3820-13-willy@infradead.org Signed-off-by: Matthew Wilcox Acked-by: Vlastimil Babka Cc: Christoph Lameter Cc: Dave Hansen Cc: Jérôme Glisse Cc: "Kirill A . Shutemov" Cc: Lai Jiangshan Cc: Martin Schwidefsky Cc: Pekka Enberg Cc: Randy Dunlap Cc: Andrey Ryabinin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86/mm/pgtable.c | 5 ++--- include/linux/mm_types.h | 2 +- 2 files changed, 3 insertions(+), 4 deletions(-) diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index ffc8c13c50e4..938dbcd46b97 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -114,13 +114,12 @@ static inline void pgd_list_del(pgd_t *pgd) static void pgd_set_mm(pgd_t *pgd, struct mm_struct *mm) { - BUILD_BUG_ON(sizeof(virt_to_page(pgd)->index) < sizeof(mm)); - virt_to_page(pgd)->index = (pgoff_t)mm; + virt_to_page(pgd)->pt_mm = mm; } struct mm_struct *pgd_page_get_mm(struct page *page) { - return (struct mm_struct *)page->index; + return page->pt_mm; } static void pgd_ctor(struct mm_struct *mm, pgd_t *pgd) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 9b45760cc797..811aa0c71e1a 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -139,7 +139,7 @@ struct page { unsigned long _pt_pad_1; /* compound_head */ pgtable_t pmd_huge_pte; /* protected by page->ptl */ unsigned long _pt_pad_2; /* mapping */ - unsigned long _pt_pad_3; + struct mm_struct *pt_mm; /* x86 pgds only */ #if ALLOC_SPLIT_PTLOCKS spinlock_t *ptl; #else -- 2.11.0