From: "Matthew Wilcox (Oracle)" <[email protected]> Instead of a per-arch word within struct page, use a formerly reserved word. This word is shared with page->mapping, so it must be cleared before being freed as it is checked in free_pages().
Signed-off-by: Matthew Wilcox (Oracle) <[email protected]> --- arch/x86/mm/pgtable.c | 1 + include/linux/mm_types.h | 7 ++----- 2 files changed, 3 insertions(+), 5 deletions(-) diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index 7bd2c3a52297..f5f46737aea0 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -95,6 +95,7 @@ static inline void pgd_list_del(pgd_t *pgd) struct page *page = virt_to_page(pgd); list_del(&page->lru); + page->pt_mm = NULL; } #define UNSHARED_PTRS_PER_PGD \ diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 9bb34e2cd5a5..7efa12f4626f 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -149,11 +149,8 @@ struct page { pgtable_t pmd_huge_pte; }; }; - unsigned long _pt_pad_2; /* mapping */ - union { - struct mm_struct *pt_mm; /* x86 pgds only */ - atomic_t pt_frag_refcount; /* powerpc */ - }; + struct mm_struct *pt_mm; + atomic_t pt_frag_refcount; /* powerpc */ #if ALLOC_SPLIT_PTLOCKS spinlock_t *ptl; #else -- 2.26.2
