diff options
Diffstat (limited to '0001-mm-thp-Do-not-make-page-table-dirty-unconditionally-.patch')
| -rw-r--r-- | 0001-mm-thp-Do-not-make-page-table-dirty-unconditionally-.patch | 108 |
1 files changed, 0 insertions, 108 deletions
diff --git a/0001-mm-thp-Do-not-make-page-table-dirty-unconditionally-.patch b/0001-mm-thp-Do-not-make-page-table-dirty-unconditionally-.patch deleted file mode 100644 index 2a1d7b719..000000000 --- a/0001-mm-thp-Do-not-make-page-table-dirty-unconditionally-.patch +++ /dev/null @@ -1,108 +0,0 @@ -From a8f97366452ed491d13cf1e44241bc0b5740b1f0 Mon Sep 17 00:00:00 2001 -From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> -Date: Mon, 27 Nov 2017 06:21:25 +0300 -Subject: [PATCH] mm, thp: Do not make page table dirty unconditionally in - touch_p[mu]d() - -Currently, we unconditionally make page table dirty in touch_pmd(). -It may result in false-positive can_follow_write_pmd(). - -We may avoid the situation, if we would only make the page table entry -dirty if caller asks for write access -- FOLL_WRITE. - -The patch also changes touch_pud() in the same way. - -Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> -Cc: Michal Hocko <mhocko@suse.com> -Cc: Hugh Dickins <hughd@google.com> -Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> ---- - mm/huge_memory.c | 36 +++++++++++++----------------------- - 1 file changed, 13 insertions(+), 23 deletions(-) - -diff --git a/mm/huge_memory.c b/mm/huge_memory.c -index 86fe697e8bfb..0e7ded98d114 100644 ---- a/mm/huge_memory.c -+++ b/mm/huge_memory.c -@@ -842,20 +842,15 @@ EXPORT_SYMBOL_GPL(vmf_insert_pfn_pud); - #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ - - static void touch_pmd(struct vm_area_struct *vma, unsigned long addr, -- pmd_t *pmd) -+ pmd_t *pmd, int flags) - { - pmd_t _pmd; - -- /* -- * We should set the dirty bit only for FOLL_WRITE but for now -- * the dirty bit in the pmd is meaningless. And if the dirty -- * bit will become meaningful and we'll only set it with -- * FOLL_WRITE, an atomic set_bit will be required on the pmd to -- * set the young bit, instead of the current set_pmd_at. -- */ -- _pmd = pmd_mkyoung(pmd_mkdirty(*pmd)); -+ _pmd = pmd_mkyoung(*pmd); -+ if (flags & FOLL_WRITE) -+ _pmd = pmd_mkdirty(_pmd); - if (pmdp_set_access_flags(vma, addr & HPAGE_PMD_MASK, -- pmd, _pmd, 1)) -+ pmd, _pmd, flags & FOLL_WRITE)) - update_mmu_cache_pmd(vma, addr, pmd); - } - -@@ -884,7 +879,7 @@ struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr, - return NULL; - - if (flags & FOLL_TOUCH) -- touch_pmd(vma, addr, pmd); -+ touch_pmd(vma, addr, pmd, flags); - - /* - * device mapped pages can only be returned if the -@@ -995,20 +990,15 @@ int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm, - - #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD - static void touch_pud(struct vm_area_struct *vma, unsigned long addr, -- pud_t *pud) -+ pud_t *pud, int flags) - { - pud_t _pud; - -- /* -- * We should set the dirty bit only for FOLL_WRITE but for now -- * the dirty bit in the pud is meaningless. And if the dirty -- * bit will become meaningful and we'll only set it with -- * FOLL_WRITE, an atomic set_bit will be required on the pud to -- * set the young bit, instead of the current set_pud_at. -- */ -- _pud = pud_mkyoung(pud_mkdirty(*pud)); -+ _pud = pud_mkyoung(*pud); -+ if (flags & FOLL_WRITE) -+ _pud = pud_mkdirty(_pud); - if (pudp_set_access_flags(vma, addr & HPAGE_PUD_MASK, -- pud, _pud, 1)) -+ pud, _pud, flags & FOLL_WRITE)) - update_mmu_cache_pud(vma, addr, pud); - } - -@@ -1031,7 +1021,7 @@ struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr, - return NULL; - - if (flags & FOLL_TOUCH) -- touch_pud(vma, addr, pud); -+ touch_pud(vma, addr, pud, flags); - - /* - * device mapped pages can only be returned if the -@@ -1424,7 +1414,7 @@ struct page *follow_trans_huge_pmd(struct vm_area_struct *vma, - page = pmd_page(*pmd); - VM_BUG_ON_PAGE(!PageHead(page) && !is_zone_device_page(page), page); - if (flags & FOLL_TOUCH) -- touch_pmd(vma, addr, pmd); -+ touch_pmd(vma, addr, pmd, flags); - if ((flags & FOLL_MLOCK) && (vma->vm_flags & VM_LOCKED)) { - /* - * We don't mlock() pte-mapped THPs. This way we can avoid --- -2.14.3 - |