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authorNick Piggin <npiggin@suse.de>2008-10-18 20:26:51 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-10-20 08:52:31 -0700
commit5344b7e648980cc2ca613ec03a56a8222ff48820 (patch)
treef9f8773ae8e38fb91aec52ca9ad2bd81f039b565 /mm
parentba470de43188cdbff795b5da43a1474523c6c2fb (diff)
vmstat: mlocked pages statistics
Add NR_MLOCK zone page state, which provides a (conservative) count of mlocked pages (actually, the number of mlocked pages moved off the LRU). Reworked by lts to fit in with the modified mlock page support in the Reclaim Scalability series. [kosaki.motohiro@jp.fujitsu.com: fix incorrect Mlocked field of /proc/meminfo] [lee.schermerhorn@hp.com: mlocked-pages: add event counting with statistics] Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/internal.h16
-rw-r--r--mm/mlock.c41
-rw-r--r--mm/vmstat.c5
3 files changed, 54 insertions, 8 deletions
diff --git a/mm/internal.h b/mm/internal.h
index 48e32f79057..1cfbf2e2bc9 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -101,7 +101,10 @@ static inline int is_mlocked_vma(struct vm_area_struct *vma, struct page *page)
if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED))
return 0;
- SetPageMlocked(page);
+ if (!TestSetPageMlocked(page)) {
+ inc_zone_page_state(page, NR_MLOCK);
+ count_vm_event(UNEVICTABLE_PGMLOCKED);
+ }
return 1;
}
@@ -128,12 +131,19 @@ static inline void clear_page_mlock(struct page *page)
/*
* mlock_migrate_page - called only from migrate_page_copy() to
- * migrate the Mlocked page flag
+ * migrate the Mlocked page flag; update statistics.
*/
static inline void mlock_migrate_page(struct page *newpage, struct page *page)
{
- if (TestClearPageMlocked(page))
+ if (TestClearPageMlocked(page)) {
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __dec_zone_page_state(page, NR_MLOCK);
SetPageMlocked(newpage);
+ __inc_zone_page_state(newpage, NR_MLOCK);
+ local_irq_restore(flags);
+ }
}
diff --git a/mm/mlock.c b/mm/mlock.c
index 8b478350a2a..bce1b22c36c 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -60,6 +60,8 @@ void __clear_page_mlock(struct page *page)
return;
}
+ dec_zone_page_state(page, NR_MLOCK);
+ count_vm_event(UNEVICTABLE_PGCLEARED);
if (!isolate_lru_page(page)) {
putback_lru_page(page);
} else {
@@ -69,6 +71,9 @@ void __clear_page_mlock(struct page *page)
lru_add_drain_all();
if (!isolate_lru_page(page))
putback_lru_page(page);
+ else if (PageUnevictable(page))
+ count_vm_event(UNEVICTABLE_PGSTRANDED);
+
}
}
@@ -80,8 +85,12 @@ void mlock_vma_page(struct page *page)
{
BUG_ON(!PageLocked(page));
- if (!TestSetPageMlocked(page) && !isolate_lru_page(page))
- putback_lru_page(page);
+ if (!TestSetPageMlocked(page)) {
+ inc_zone_page_state(page, NR_MLOCK);
+ count_vm_event(UNEVICTABLE_PGMLOCKED);
+ if (!isolate_lru_page(page))
+ putback_lru_page(page);
+ }
}
/*
@@ -106,9 +115,31 @@ static void munlock_vma_page(struct page *page)
{
BUG_ON(!PageLocked(page));
- if (TestClearPageMlocked(page) && !isolate_lru_page(page)) {
- try_to_munlock(page);
- putback_lru_page(page);
+ if (TestClearPageMlocked(page)) {
+ dec_zone_page_state(page, NR_MLOCK);
+ if (!isolate_lru_page(page)) {
+ int ret = try_to_munlock(page);
+ /*
+ * did try_to_unlock() succeed or punt?
+ */
+ if (ret == SWAP_SUCCESS || ret == SWAP_AGAIN)
+ count_vm_event(UNEVICTABLE_PGMUNLOCKED);
+
+ putback_lru_page(page);
+ } else {
+ /*
+ * We lost the race. let try_to_unmap() deal
+ * with it. At least we get the page state and
+ * mlock stats right. However, page is still on
+ * the noreclaim list. We'll fix that up when
+ * the page is eventually freed or we scan the
+ * noreclaim list.
+ */
+ if (PageUnevictable(page))
+ count_vm_event(UNEVICTABLE_PGSTRANDED);
+ else
+ count_vm_event(UNEVICTABLE_PGMUNLOCKED);
+ }
}
}
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 6db2f631931..9e28abc0a0b 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -625,6 +625,7 @@ static const char * const vmstat_text[] = {
"nr_active_file",
#ifdef CONFIG_UNEVICTABLE_LRU
"nr_unevictable",
+ "nr_mlock",
#endif
"nr_anon_pages",
"nr_mapped",
@@ -684,6 +685,10 @@ static const char * const vmstat_text[] = {
"unevictable_pgs_culled",
"unevictable_pgs_scanned",
"unevictable_pgs_rescued",
+ "unevictable_pgs_mlocked",
+ "unevictable_pgs_munlocked",
+ "unevictable_pgs_cleared",
+ "unevictable_pgs_stranded",
#endif
#endif
};