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-rw-r--r--include/linux/rmap.h22
-rw-r--r--mm/memory.c6
-rw-r--r--mm/rmap.c7
3 files changed, 25 insertions, 10 deletions
diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index 73f41544084f..c53a38151089 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -160,9 +160,23 @@ static inline void anon_vma_merge(struct vm_area_struct *vma,
struct anon_vma *page_get_anon_vma(struct page *page);
-/* bitflags for do_page_add_anon_rmap() */
-#define RMAP_EXCLUSIVE 0x01
-#define RMAP_COMPOUND 0x02
+/* RMAP flags, currently only relevant for some anon rmap operations. */
+typedef int __bitwise rmap_t;
+
+/*
+ * No special request: if the page is a subpage of a compound page, it is
+ * mapped via a PTE. The mapped (sub)page is possibly shared between processes.
+ */
+#define RMAP_NONE ((__force rmap_t)0)
+
+/* The (sub)page is exclusive to a single process. */
+#define RMAP_EXCLUSIVE ((__force rmap_t)BIT(0))
+
+/*
+ * The compound page is not mapped via PTEs, but instead via a single PMD and
+ * should be accounted accordingly.
+ */
+#define RMAP_COMPOUND ((__force rmap_t)BIT(1))
/*
* rmap interfaces called when adding or removing pte of page
@@ -171,7 +185,7 @@ void page_move_anon_rmap(struct page *, struct vm_area_struct *);
void page_add_anon_rmap(struct page *, struct vm_area_struct *,
unsigned long address, bool compound);
void do_page_add_anon_rmap(struct page *, struct vm_area_struct *,
- unsigned long address, int flags);
+ unsigned long address, rmap_t flags);
void page_add_new_anon_rmap(struct page *, struct vm_area_struct *,
unsigned long address, bool compound);
void page_add_file_rmap(struct page *, struct vm_area_struct *,
diff --git a/mm/memory.c b/mm/memory.c
index 9f5f829a1b1f..4cd8cadf1268 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3511,10 +3511,10 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
struct vm_area_struct *vma = vmf->vma;
struct page *page = NULL, *swapcache;
struct swap_info_struct *si = NULL;
+ rmap_t rmap_flags = RMAP_NONE;
swp_entry_t entry;
pte_t pte;
int locked;
- int exclusive = 0;
vm_fault_t ret = 0;
void *shadow = NULL;
@@ -3689,7 +3689,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
pte = maybe_mkwrite(pte_mkdirty(pte), vma);
vmf->flags &= ~FAULT_FLAG_WRITE;
ret |= VM_FAULT_WRITE;
- exclusive = RMAP_EXCLUSIVE;
+ rmap_flags |= RMAP_EXCLUSIVE;
}
flush_icache_page(vma, page);
if (pte_swp_soft_dirty(vmf->orig_pte))
@@ -3705,7 +3705,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
page_add_new_anon_rmap(page, vma, vmf->address, false);
lru_cache_add_inactive_or_unevictable(page, vma);
} else {
- do_page_add_anon_rmap(page, vma, vmf->address, exclusive);
+ do_page_add_anon_rmap(page, vma, vmf->address, rmap_flags);
}
set_pte_at(vma->vm_mm, vmf->address, vmf->pte, pte);
diff --git a/mm/rmap.c b/mm/rmap.c
index 91a63dc636ad..23a41132995e 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1181,7 +1181,8 @@ static void __page_check_anon_rmap(struct page *page,
void page_add_anon_rmap(struct page *page,
struct vm_area_struct *vma, unsigned long address, bool compound)
{
- do_page_add_anon_rmap(page, vma, address, compound ? RMAP_COMPOUND : 0);
+ do_page_add_anon_rmap(page, vma, address,
+ compound ? RMAP_COMPOUND : RMAP_NONE);
}
/*
@@ -1190,7 +1191,7 @@ void page_add_anon_rmap(struct page *page,
* Everybody else should continue to use page_add_anon_rmap above.
*/
void do_page_add_anon_rmap(struct page *page,
- struct vm_area_struct *vma, unsigned long address, int flags)
+ struct vm_area_struct *vma, unsigned long address, rmap_t flags)
{
bool compound = flags & RMAP_COMPOUND;
bool first;
@@ -1229,7 +1230,7 @@ void do_page_add_anon_rmap(struct page *page,
/* address might be in next vma when migration races vma_adjust */
else if (first)
__page_set_anon_rmap(page, vma, address,
- flags & RMAP_EXCLUSIVE);
+ !!(flags & RMAP_EXCLUSIVE));
else
__page_check_anon_rmap(page, vma, address);