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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-01-20 14:01:31 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-01-20 14:01:31 -0300
commitb4b7ff4b08e691656c9d77c758fc355833128ac0 (patch)
tree82fcb00e6b918026dc9f2d1f05ed8eee83874cc0 /mm/rmap.c
parent35acfa0fc609f2a2cd95cef4a6a9c3a5c38f1778 (diff)
Linux-libre 4.4-gnupck-4.4-gnu
Diffstat (limited to 'mm/rmap.c')
-rw-r--r--mm/rmap.c107
1 files changed, 48 insertions, 59 deletions
diff --git a/mm/rmap.c b/mm/rmap.c
index b8fb8d8e1..c0d802a5a 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1304,6 +1304,10 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
int ret = SWAP_AGAIN;
enum ttu_flags flags = (enum ttu_flags)arg;
+ /* munlock has nothing to gain from examining un-locked vmas */
+ if ((flags & TTU_MUNLOCK) && !(vma->vm_flags & VM_LOCKED))
+ goto out;
+
pte = page_check_address(page, mm, address, &ptl, 0);
if (!pte)
goto out;
@@ -1314,9 +1318,12 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
* skipped over this mm) then we should reactivate it.
*/
if (!(flags & TTU_IGNORE_MLOCK)) {
- if (vma->vm_flags & VM_LOCKED)
- goto out_mlock;
-
+ if (vma->vm_flags & VM_LOCKED) {
+ /* Holding pte lock, we do *not* need mmap_sem here */
+ mlock_vma_page(page);
+ ret = SWAP_MLOCK;
+ goto out_unmap;
+ }
if (flags & TTU_MUNLOCK)
goto out_unmap;
}
@@ -1352,7 +1359,9 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
update_hiwater_rss(mm);
if (PageHWPoison(page) && !(flags & TTU_IGNORE_HWPOISON)) {
- if (!PageHuge(page)) {
+ if (PageHuge(page)) {
+ hugetlb_count_sub(1 << compound_order(page), mm);
+ } else {
if (PageAnon(page))
dec_mm_counter(mm, MM_ANONPAGES);
else
@@ -1370,47 +1379,44 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
dec_mm_counter(mm, MM_ANONPAGES);
else
dec_mm_counter(mm, MM_FILEPAGES);
+ } else if (IS_ENABLED(CONFIG_MIGRATION) && (flags & TTU_MIGRATION)) {
+ swp_entry_t entry;
+ pte_t swp_pte;
+ /*
+ * Store the pfn of the page in a special migration
+ * pte. do_swap_page() will wait until the migration
+ * pte is removed and then restart fault handling.
+ */
+ entry = make_migration_entry(page, pte_write(pteval));
+ swp_pte = swp_entry_to_pte(entry);
+ if (pte_soft_dirty(pteval))
+ swp_pte = pte_swp_mksoft_dirty(swp_pte);
+ set_pte_at(mm, address, pte, swp_pte);
} else if (PageAnon(page)) {
swp_entry_t entry = { .val = page_private(page) };
pte_t swp_pte;
-
- if (PageSwapCache(page)) {
- /*
- * Store the swap location in the pte.
- * See handle_pte_fault() ...
- */
- if (swap_duplicate(entry) < 0) {
- set_pte_at(mm, address, pte, pteval);
- ret = SWAP_FAIL;
- goto out_unmap;
- }
- if (list_empty(&mm->mmlist)) {
- spin_lock(&mmlist_lock);
- if (list_empty(&mm->mmlist))
- list_add(&mm->mmlist, &init_mm.mmlist);
- spin_unlock(&mmlist_lock);
- }
- dec_mm_counter(mm, MM_ANONPAGES);
- inc_mm_counter(mm, MM_SWAPENTS);
- } else if (IS_ENABLED(CONFIG_MIGRATION)) {
- /*
- * Store the pfn of the page in a special migration
- * pte. do_swap_page() will wait until the migration
- * pte is removed and then restart fault handling.
- */
- BUG_ON(!(flags & TTU_MIGRATION));
- entry = make_migration_entry(page, pte_write(pteval));
+ /*
+ * Store the swap location in the pte.
+ * See handle_pte_fault() ...
+ */
+ VM_BUG_ON_PAGE(!PageSwapCache(page), page);
+ if (swap_duplicate(entry) < 0) {
+ set_pte_at(mm, address, pte, pteval);
+ ret = SWAP_FAIL;
+ goto out_unmap;
+ }
+ if (list_empty(&mm->mmlist)) {
+ spin_lock(&mmlist_lock);
+ if (list_empty(&mm->mmlist))
+ list_add(&mm->mmlist, &init_mm.mmlist);
+ spin_unlock(&mmlist_lock);
}
+ dec_mm_counter(mm, MM_ANONPAGES);
+ inc_mm_counter(mm, MM_SWAPENTS);
swp_pte = swp_entry_to_pte(entry);
if (pte_soft_dirty(pteval))
swp_pte = pte_swp_mksoft_dirty(swp_pte);
set_pte_at(mm, address, pte, swp_pte);
- } else if (IS_ENABLED(CONFIG_MIGRATION) &&
- (flags & TTU_MIGRATION)) {
- /* Establish migration entry for a file page */
- swp_entry_t entry;
- entry = make_migration_entry(page, pte_write(pteval));
- set_pte_at(mm, address, pte, swp_entry_to_pte(entry));
} else
dec_mm_counter(mm, MM_FILEPAGES);
@@ -1419,31 +1425,10 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
out_unmap:
pte_unmap_unlock(pte, ptl);
- if (ret != SWAP_FAIL && !(flags & TTU_MUNLOCK))
+ if (ret != SWAP_FAIL && ret != SWAP_MLOCK && !(flags & TTU_MUNLOCK))
mmu_notifier_invalidate_page(mm, address);
out:
return ret;
-
-out_mlock:
- pte_unmap_unlock(pte, ptl);
-
-
- /*
- * We need mmap_sem locking, Otherwise VM_LOCKED check makes
- * unstable result and race. Plus, We can't wait here because
- * we now hold anon_vma->rwsem or mapping->i_mmap_rwsem.
- * if trylock failed, the page remain in evictable lru and later
- * vmscan could retry to move the page to unevictable lru if the
- * page is actually mlocked.
- */
- if (down_read_trylock(&vma->vm_mm->mmap_sem)) {
- if (vma->vm_flags & VM_LOCKED) {
- mlock_vma_page(page);
- ret = SWAP_MLOCK;
- }
- up_read(&vma->vm_mm->mmap_sem);
- }
- return ret;
}
bool is_vma_temporary_stack(struct vm_area_struct *vma)
@@ -1607,6 +1592,8 @@ static int rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc)
struct vm_area_struct *vma = avc->vma;
unsigned long address = vma_address(page, vma);
+ cond_resched();
+
if (rwc->invalid_vma && rwc->invalid_vma(vma, rwc->arg))
continue;
@@ -1656,6 +1643,8 @@ static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc)
vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
unsigned long address = vma_address(page, vma);
+ cond_resched();
+
if (rwc->invalid_vma && rwc->invalid_vma(vma, rwc->arg))
continue;