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-rw-r--r--include/linux/rmap.h2
-rw-r--r--mm/rmap.c3
-rw-r--r--mm/vmscan.c45
3 files changed, 36 insertions, 14 deletions
diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index 72be23b1480a..d25bd224d370 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -209,7 +209,7 @@ static inline int page_referenced(struct page *page, int is_locked,
unsigned long *vm_flags)
{
*vm_flags = 0;
- return TestClearPageReferenced(page);
+ return 0;
}
#define try_to_unmap(page, refs) SWAP_FAIL
diff --git a/mm/rmap.c b/mm/rmap.c
index 4d2fb93851ca..fcd593c9c997 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -601,9 +601,6 @@ int page_referenced(struct page *page,
int referenced = 0;
int we_locked = 0;
- if (TestClearPageReferenced(page))
- referenced++;
-
*vm_flags = 0;
if (page_mapped(page) && page_rmapping(page)) {
if (!is_locked && (!PageAnon(page) || PageKsm(page))) {
diff --git a/mm/vmscan.c b/mm/vmscan.c
index d9a0e0d3aac7..79c809895fba 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -561,18 +561,18 @@ redo:
enum page_references {
PAGEREF_RECLAIM,
PAGEREF_RECLAIM_CLEAN,
+ PAGEREF_KEEP,
PAGEREF_ACTIVATE,
};
static enum page_references page_check_references(struct page *page,
struct scan_control *sc)
{
+ int referenced_ptes, referenced_page;
unsigned long vm_flags;
- int referenced;
- referenced = page_referenced(page, 1, sc->mem_cgroup, &vm_flags);
- if (!referenced)
- return PAGEREF_RECLAIM;
+ referenced_ptes = page_referenced(page, 1, sc->mem_cgroup, &vm_flags);
+ referenced_page = TestClearPageReferenced(page);
/* Lumpy reclaim - ignore references */
if (sc->order > PAGE_ALLOC_COSTLY_ORDER)
@@ -585,11 +585,36 @@ static enum page_references page_check_references(struct page *page,
if (vm_flags & VM_LOCKED)
return PAGEREF_RECLAIM;
- if (page_mapped(page))
- return PAGEREF_ACTIVATE;
+ if (referenced_ptes) {
+ if (PageAnon(page))
+ return PAGEREF_ACTIVATE;
+ /*
+ * All mapped pages start out with page table
+ * references from the instantiating fault, so we need
+ * to look twice if a mapped file page is used more
+ * than once.
+ *
+ * Mark it and spare it for another trip around the
+ * inactive list. Another page table reference will
+ * lead to its activation.
+ *
+ * Note: the mark is set for activated pages as well
+ * so that recently deactivated but used pages are
+ * quickly recovered.
+ */
+ SetPageReferenced(page);
+
+ if (referenced_page)
+ return PAGEREF_ACTIVATE;
+
+ return PAGEREF_KEEP;
+ }
/* Reclaim if clean, defer dirty pages to writeback */
- return PAGEREF_RECLAIM_CLEAN;
+ if (referenced_page)
+ return PAGEREF_RECLAIM_CLEAN;
+
+ return PAGEREF_RECLAIM;
}
/*
@@ -657,6 +682,8 @@ static unsigned long shrink_page_list(struct list_head *page_list,
switch (references) {
case PAGEREF_ACTIVATE:
goto activate_locked;
+ case PAGEREF_KEEP:
+ goto keep_locked;
case PAGEREF_RECLAIM:
case PAGEREF_RECLAIM_CLEAN:
; /* try to reclaim the page below */
@@ -1359,9 +1386,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
continue;
}
- /* page_referenced clears PageReferenced */
- if (page_mapped(page) &&
- page_referenced(page, 0, sc->mem_cgroup, &vm_flags)) {
+ if (page_referenced(page, 0, sc->mem_cgroup, &vm_flags)) {
nr_rotated++;
/*
* Identify referenced, file-backed active pages and

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