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-rw-r--r--mm/rmap.c70
1 files changed, 44 insertions, 26 deletions
diff --git a/mm/rmap.c b/mm/rmap.c
index c8454e0..5b5ad58 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -120,6 +120,21 @@ static void anon_vma_chain_free(struct anon_vma_chain *anon_vma_chain)
kmem_cache_free(anon_vma_chain_cachep, anon_vma_chain);
}
+static void anon_vma_chain_link(struct vm_area_struct *vma,
+ struct anon_vma_chain *avc,
+ struct anon_vma *anon_vma)
+{
+ avc->vma = vma;
+ avc->anon_vma = anon_vma;
+ list_add(&avc->same_vma, &vma->anon_vma_chain);
+
+ /*
+ * It's critical to add new vmas to the tail of the anon_vma,
+ * see comment in huge_memory.c:__split_huge_page().
+ */
+ list_add_tail(&avc->same_anon_vma, &anon_vma->head);
+}
+
/**
* anon_vma_prepare - attach an anon_vma to a memory region
* @vma: the memory region in question
@@ -175,10 +190,7 @@ int anon_vma_prepare(struct vm_area_struct *vma)
spin_lock(&mm->page_table_lock);
if (likely(!vma->anon_vma)) {
vma->anon_vma = anon_vma;
- avc->anon_vma = anon_vma;
- avc->vma = vma;
- list_add(&avc->same_vma, &vma->anon_vma_chain);
- list_add_tail(&avc->same_anon_vma, &anon_vma->head);
+ anon_vma_chain_link(vma, avc, anon_vma);
allocated = NULL;
avc = NULL;
}
@@ -224,21 +236,6 @@ static inline void unlock_anon_vma_root(struct anon_vma *root)
mutex_unlock(&root->mutex);
}
-static void anon_vma_chain_link(struct vm_area_struct *vma,
- struct anon_vma_chain *avc,
- struct anon_vma *anon_vma)
-{
- avc->vma = vma;
- avc->anon_vma = anon_vma;
- list_add(&avc->same_vma, &vma->anon_vma_chain);
-
- /*
- * It's critical to add new vmas to the tail of the anon_vma,
- * see comment in huge_memory.c:__split_huge_page().
- */
- list_add_tail(&avc->same_anon_vma, &anon_vma->head);
-}
-
/*
* Attach the anon_vmas from src to dst.
* Returns 0 on success, -ENOMEM on failure.
@@ -1151,10 +1148,15 @@ void page_add_new_anon_rmap(struct page *page,
*/
void page_add_file_rmap(struct page *page)
{
+ bool locked;
+ unsigned long flags;
+
+ mem_cgroup_begin_update_page_stat(page, &locked, &flags);
if (atomic_inc_and_test(&page->_mapcount)) {
__inc_zone_page_state(page, NR_FILE_MAPPED);
mem_cgroup_inc_page_stat(page, MEMCG_NR_FILE_MAPPED);
}
+ mem_cgroup_end_update_page_stat(page, &locked, &flags);
}
/**
@@ -1165,9 +1167,21 @@ void page_add_file_rmap(struct page *page)
*/
void page_remove_rmap(struct page *page)
{
+ bool anon = PageAnon(page);
+ bool locked;
+ unsigned long flags;
+
+ /*
+ * The anon case has no mem_cgroup page_stat to update; but may
+ * uncharge_page() below, where the lock ordering can deadlock if
+ * we hold the lock against page_stat move: so avoid it on anon.
+ */
+ if (!anon)
+ mem_cgroup_begin_update_page_stat(page, &locked, &flags);
+
/* page still mapped by someone else? */
if (!atomic_add_negative(-1, &page->_mapcount))
- return;
+ goto out;
/*
* Now that the last pte has gone, s390 must transfer dirty
@@ -1176,7 +1190,7 @@ void page_remove_rmap(struct page *page)
* not if it's in swapcache - there might be another pte slot
* containing the swap entry, but page not yet written to swap.
*/
- if ((!PageAnon(page) || PageSwapCache(page)) &&
+ if ((!anon || PageSwapCache(page)) &&
page_test_and_clear_dirty(page_to_pfn(page), 1))
set_page_dirty(page);
/*
@@ -1184,8 +1198,8 @@ void page_remove_rmap(struct page *page)
* and not charged by memcg for now.
*/
if (unlikely(PageHuge(page)))
- return;
- if (PageAnon(page)) {
+ goto out;
+ if (anon) {
mem_cgroup_uncharge_page(page);
if (!PageTransHuge(page))
__dec_zone_page_state(page, NR_ANON_PAGES);
@@ -1205,6 +1219,9 @@ void page_remove_rmap(struct page *page)
* Leaving it set also helps swapoff to reinstate ptes
* faster for those pages still in swapcache.
*/
+out:
+ if (!anon)
+ mem_cgroup_end_update_page_stat(page, &locked, &flags);
}
/*
@@ -1282,7 +1299,7 @@ int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
}
dec_mm_counter(mm, MM_ANONPAGES);
inc_mm_counter(mm, MM_SWAPENTS);
- } else if (PAGE_MIGRATION) {
+ } 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
@@ -1293,7 +1310,8 @@ int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
}
set_pte_at(mm, address, pte, swp_entry_to_pte(entry));
BUG_ON(pte_file(*pte));
- } else if (PAGE_MIGRATION && (TTU_ACTION(flags) == TTU_MIGRATION)) {
+ } else if (IS_ENABLED(CONFIG_MIGRATION) &&
+ (TTU_ACTION(flags) == TTU_MIGRATION)) {
/* Establish migration entry for a file page */
swp_entry_t entry;
entry = make_migration_entry(page, pte_write(pteval));
@@ -1499,7 +1517,7 @@ static int try_to_unmap_anon(struct page *page, enum ttu_flags flags)
* locking requirements of exec(), migration skips
* temporary VMAs until after exec() completes.
*/
- if (PAGE_MIGRATION && (flags & TTU_MIGRATION) &&
+ if (IS_ENABLED(CONFIG_MIGRATION) && (flags & TTU_MIGRATION) &&
is_vma_temporary_stack(vma))
continue;
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