diff options
| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2016-03-18 00:20:04 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-03-18 01:09:34 +0300 |
| commit | 2a52bcbcc688eecead2953143f7ef695b8e44575 (patch) | |
| tree | b2e372875693775e97fc4e9373c5a630d2a1dcc0 /mm | |
| parent | b97731992d00f09456726bfc5ab6641c07773038 (diff) | |
| download | linux-2a52bcbcc688eecead2953143f7ef695b8e44575.tar.xz | |
rmap: extend try_to_unmap() to be usable by split_huge_page()
Add support for two ttu_flags:
- TTU_SPLIT_HUGE_PMD would split PMD if it's there, before trying to
unmap page;
- TTU_RMAP_LOCKED indicates that caller holds relevant rmap lock;
Also, change rwc->done to !page_mapcount() instead of !page_mapped().
try_to_unmap() works on pte level, so we are really interested in the
mappedness of this small page rather than of the compound page it's a
part of.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/huge_memory.c | 5 | ||||
| -rw-r--r-- | mm/rmap.c | 24 |
2 files changed, 17 insertions, 12 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index e1a177c20791..11d15674ff38 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -3006,15 +3006,12 @@ out: } } -static void split_huge_pmd_address(struct vm_area_struct *vma, - unsigned long address) +void split_huge_pmd_address(struct vm_area_struct *vma, unsigned long address) { pgd_t *pgd; pud_t *pud; pmd_t *pmd; - VM_BUG_ON(!(address & ~HPAGE_PMD_MASK)); - pgd = pgd_offset(vma->vm_mm, address); if (!pgd_present(*pgd)) return; diff --git a/mm/rmap.c b/mm/rmap.c index 30b739ce0ffa..945933a01010 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1431,6 +1431,8 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma, if ((flags & TTU_MUNLOCK) && !(vma->vm_flags & VM_LOCKED)) goto out; + if (flags & TTU_SPLIT_HUGE_PMD) + split_huge_pmd_address(vma, address); pte = page_check_address(page, mm, address, &ptl, 0); if (!pte) goto out; @@ -1576,10 +1578,10 @@ static bool invalid_migration_vma(struct vm_area_struct *vma, void *arg) return is_vma_temporary_stack(vma); } -static int page_not_mapped(struct page *page) +static int page_mapcount_is_zero(struct page *page) { - return !page_mapped(page); -}; + return !page_mapcount(page); +} /** * try_to_unmap - try to remove all page table mappings to a page @@ -1606,12 +1608,10 @@ int try_to_unmap(struct page *page, enum ttu_flags flags) struct rmap_walk_control rwc = { .rmap_one = try_to_unmap_one, .arg = &rp, - .done = page_not_mapped, + .done = page_mapcount_is_zero, .anon_lock = page_lock_anon_vma_read, }; - VM_BUG_ON_PAGE(!PageHuge(page) && PageTransHuge(page), page); - /* * During exec, a temporary VMA is setup and later moved. * The VMA is moved under the anon_vma lock but not the @@ -1623,9 +1623,12 @@ int try_to_unmap(struct page *page, enum ttu_flags flags) if ((flags & TTU_MIGRATION) && !PageKsm(page) && PageAnon(page)) rwc.invalid_vma = invalid_migration_vma; - ret = rmap_walk(page, &rwc); + if (flags & TTU_RMAP_LOCKED) + ret = rmap_walk_locked(page, &rwc); + else + ret = rmap_walk(page, &rwc); - if (ret != SWAP_MLOCK && !page_mapped(page)) { + if (ret != SWAP_MLOCK && !page_mapcount(page)) { ret = SWAP_SUCCESS; if (rp.lazyfreed && !PageDirty(page)) ret = SWAP_LZFREE; @@ -1633,6 +1636,11 @@ int try_to_unmap(struct page *page, enum ttu_flags flags) return ret; } +static int page_not_mapped(struct page *page) +{ + return !page_mapped(page); +}; + /** * try_to_munlock - try to munlock a page * @page: the page to be munlocked |