[PATCH 63 of 66] fix anon memory statistics with transparent hugepages

From: Andrea Arcangeli
Date: Wed Nov 03 2010 - 11:33:18 EST


From: Rik van Riel <riel@xxxxxxxxxx>

Count each transparent hugepage as HPAGE_PMD_NR pages in the LRU
statistics, so the Active(anon) and Inactive(anon) statistics in
/proc/meminfo are correct.

Signed-off-by: Rik van Riel <riel@xxxxxxxxxx>
Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
---

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -128,11 +128,19 @@ static inline int PageTransCompound(stru
{
return PageCompound(page);
}
+static inline int hpage_nr_pages(struct page *page)
+{
+ if (unlikely(PageTransHuge(page)))
+ return HPAGE_PMD_NR;
+ return 1;
+}
#else /* CONFIG_TRANSPARENT_HUGEPAGE */
#define HPAGE_PMD_SHIFT ({ BUG(); 0; })
#define HPAGE_PMD_MASK ({ BUG(); 0; })
#define HPAGE_PMD_SIZE ({ BUG(); 0; })

+#define hpage_nr_pages(x) 1
+
#define transparent_hugepage_enabled(__vma) 0

#define transparent_hugepage_flags 0UL
diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h
@@ -1,6 +1,8 @@
#ifndef LINUX_MM_INLINE_H
#define LINUX_MM_INLINE_H

+#include <linux/huge_mm.h>
+
/**
* page_is_file_cache - should the page be on a file LRU or anon LRU?
* @page: the page to test
@@ -24,7 +26,7 @@ __add_page_to_lru_list(struct zone *zone
struct list_head *head)
{
list_add(&page->lru, head);
- __inc_zone_state(zone, NR_LRU_BASE + l);
+ __mod_zone_page_state(zone, NR_LRU_BASE + l, hpage_nr_pages(page));
mem_cgroup_add_lru_list(page, l);
}

@@ -38,7 +40,7 @@ static inline void
del_page_from_lru_list(struct zone *zone, struct page *page, enum lru_list l)
{
list_del(&page->lru);
- __dec_zone_state(zone, NR_LRU_BASE + l);
+ __mod_zone_page_state(zone, NR_LRU_BASE + l, -hpage_nr_pages(page));
mem_cgroup_del_lru_list(page, l);
}

@@ -73,7 +75,7 @@ del_page_from_lru(struct zone *zone, str
l += LRU_ACTIVE;
}
}
- __dec_zone_state(zone, NR_LRU_BASE + l);
+ __mod_zone_page_state(zone, NR_LRU_BASE + l, -hpage_nr_pages(page));
mem_cgroup_del_lru_list(page, l);
}

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1139,6 +1139,7 @@ static void __split_huge_page_refcount(s
int i;
unsigned long head_index = page->index;
struct zone *zone = page_zone(page);
+ int zonestat;

/* prevent PageLRU to go away from under us, and freeze lru stats */
spin_lock_irq(&zone->lru_lock);
@@ -1203,6 +1204,15 @@ static void __split_huge_page_refcount(s
__dec_zone_page_state(page, NR_ANON_TRANSPARENT_HUGEPAGES);
__mod_zone_page_state(zone, NR_ANON_PAGES, HPAGE_PMD_NR);

+ /*
+ * A hugepage counts for HPAGE_PMD_NR pages on the LRU statistics,
+ * so adjust those appropriately if this page is on the LRU.
+ */
+ if (PageLRU(page)) {
+ zonestat = NR_LRU_BASE + page_lru(page);
+ __mod_zone_page_state(zone, zonestat, -(HPAGE_PMD_NR-1));
+ }
+
ClearPageCompound(page);
compound_unlock(page);
spin_unlock_irq(&zone->lru_lock);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1083,7 +1083,7 @@ unsigned long mem_cgroup_isolate_pages(u
case 0:
list_move(&page->lru, dst);
mem_cgroup_del_lru(page);
- nr_taken++;
+ nr_taken += hpage_nr_pages(page);
break;
case -EBUSY:
/* we don't affect global LRU but rotate in our LRU */
diff --git a/mm/vmscan.c b/mm/vmscan.c
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1028,7 +1028,7 @@ static unsigned long isolate_lru_pages(u
case 0:
list_move(&page->lru, dst);
mem_cgroup_del_lru(page);
- nr_taken++;
+ nr_taken += hpage_nr_pages(page);
break;

case -EBUSY:
@@ -1086,7 +1086,7 @@ static unsigned long isolate_lru_pages(u
if (__isolate_lru_page(cursor_page, mode, file) == 0) {
list_move(&cursor_page->lru, dst);
mem_cgroup_del_lru(cursor_page);
- nr_taken++;
+ nr_taken += hpage_nr_pages(page);
nr_lumpy_taken++;
if (PageDirty(cursor_page))
nr_lumpy_dirty++;
@@ -1141,14 +1141,15 @@ static unsigned long clear_active_flags(
struct page *page;

list_for_each_entry(page, page_list, lru) {
+ int numpages = hpage_nr_pages(page);
lru = page_lru_base_type(page);
if (PageActive(page)) {
lru += LRU_ACTIVE;
ClearPageActive(page);
- nr_active++;
+ nr_active += numpages;
}
if (count)
- count[lru]++;
+ count[lru] += numpages;
}

return nr_active;
@@ -1466,7 +1467,7 @@ static void move_active_pages_to_lru(str

list_move(&page->lru, &zone->lru[lru].list);
mem_cgroup_add_lru_list(page, lru);
- pgmoved++;
+ pgmoved += hpage_nr_pages(page);

if (!pagevec_add(&pvec, page) || list_empty(list)) {
spin_unlock_irq(&zone->lru_lock);
--
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