The patch titled
vmscan: noreclaim and mlocked pages vm events
has been added to the -mm tree. Its filename is
vmscan-noreclaim-and-mlocked-pages-vm-events.patch
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------------------------------------------------------
Subject: vmscan: noreclaim and mlocked pages vm events
From: Lee Schermerhorn <lee.schermerhorn@xxxxxx>
Against: 2.6.26-rc2-mm1
Add some event counters to vmstats for testing noreclaim/mlock.
Some of these might be interesting enough to keep around.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@xxxxxx>
Signed-off-by: Rik van Riel <riel@xxxxxxxxxx>
---
Index: linux-2.6.26-rc2-mm1/include/linux/vmstat.h
===================================================================
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/vmstat.h | 11 +++++++++++
mm/internal.h | 4 +++-
mm/mlock.c | 33 +++++++++++++++++++++++++--------
mm/vmscan.c | 16 +++++++++++++++-
mm/vmstat.c | 12 ++++++++++++
5 files changed, 66 insertions(+), 10 deletions(-)
diff -puN include/linux/vmstat.h~noreclaim-and-mlocked-pages-vm-events include/linux/vmstat.h
--- a/include/linux/vmstat.h~noreclaim-and-mlocked-pages-vm-events
+++ a/include/linux/vmstat.h
@@ -41,6 +41,17 @@ enum vm_event_item { PGPGIN, PGPGOUT, PS
#ifdef CONFIG_HUGETLB_PAGE
HTLB_BUDDY_PGALLOC, HTLB_BUDDY_PGALLOC_FAIL,
#endif
+#ifdef CONFIG_NORECLAIM_LRU
+ NORECL_PGCULLED, /* culled to noreclaim list */
+ NORECL_PGSCANNED, /* scanned for reclaimability */
+ NORECL_PGRESCUED, /* rescued from noreclaim list */
+#ifdef CONFIG_NORECLAIM_MLOCK
+ NORECL_PGMLOCKED,
+ NORECL_PGMUNLOCKED,
+ NORECL_PGCLEARED,
+ NORECL_PGSTRANDED, /* unable to isolate on unlock */
+#endif
+#endif
NR_VM_EVENT_ITEMS
};
diff -puN mm/internal.h~noreclaim-and-mlocked-pages-vm-events mm/internal.h
--- a/mm/internal.h~noreclaim-and-mlocked-pages-vm-events
+++ a/mm/internal.h
@@ -110,8 +110,10 @@ static inline int is_mlocked_vma(struct
if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED))
return 0;
- if (!TestSetPageMlocked(page))
+ if (!TestSetPageMlocked(page)) {
inc_zone_page_state(page, NR_MLOCK);
+ count_vm_event(NORECL_PGMLOCKED);
+ }
return 1;
}
diff -puN mm/mlock.c~noreclaim-and-mlocked-pages-vm-events mm/mlock.c
--- a/mm/mlock.c~noreclaim-and-mlocked-pages-vm-events
+++ a/mm/mlock.c
@@ -18,6 +18,7 @@
#include <linux/rmap.h>
#include <linux/mmzone.h>
#include <linux/hugetlb.h>
+#include <linux/vmstat.h>
#include "internal.h"
@@ -57,6 +58,7 @@ void __clear_page_mlock(struct page *pag
VM_BUG_ON(!PageLocked(page)); /* for LRU islolate/putback */
dec_zone_page_state(page, NR_MLOCK);
+ count_vm_event(NORECL_PGCLEARED);
if (!isolate_lru_page(page)) {
putback_lru_page(page);
} else {
@@ -66,6 +68,8 @@ void __clear_page_mlock(struct page *pag
lru_add_drain_all();
if (!isolate_lru_page(page))
putback_lru_page(page);
+ else if (PageNoreclaim(page))
+ count_vm_event(NORECL_PGSTRANDED);
}
}
@@ -79,6 +83,7 @@ void mlock_vma_page(struct page *page)
if (!TestSetPageMlocked(page)) {
inc_zone_page_state(page, NR_MLOCK);
+ count_vm_event(NORECL_PGMLOCKED);
if (!isolate_lru_page(page))
putback_lru_page(page);
}
@@ -109,16 +114,28 @@ static void munlock_vma_page(struct page
if (TestClearPageMlocked(page)) {
dec_zone_page_state(page, NR_MLOCK);
if (!isolate_lru_page(page)) {
- try_to_unlock(page); /* maybe relock the page */
+ int ret = try_to_unlock(page);
+ /*
+ * did try_to_unlock() succeed or punt?
+ */
+ if (ret == SWAP_SUCCESS || ret == SWAP_AGAIN)
+ count_vm_event(NORECL_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 (PageNoreclaim(page))
+ count_vm_event(NORECL_PGSTRANDED);
+ else
+ count_vm_event(NORECL_PGMUNLOCKED);
}
- /*
- * 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.
- */
}
}
diff -puN mm/vmscan.c~noreclaim-and-mlocked-pages-vm-events mm/vmscan.c
--- a/mm/vmscan.c~noreclaim-and-mlocked-pages-vm-events
+++ a/mm/vmscan.c
@@ -462,12 +462,13 @@ int putback_lru_page(struct page *page)
{
int lru;
int ret = 1;
+ int was_nonreclaimable;
VM_BUG_ON(!PageLocked(page));
VM_BUG_ON(PageLRU(page));
lru = !!TestClearPageActive(page);
- ClearPageNoreclaim(page); /* for page_reclaimable() */
+ was_nonreclaimable = TestClearPageNoreclaim(page);
if (unlikely(!page->mapping)) {
/*
@@ -487,6 +488,10 @@ int putback_lru_page(struct page *page)
lru += page_file_cache(page);
lru_cache_add_lru(page, lru);
mem_cgroup_move_lists(page, lru);
+#ifdef CONFIG_NORECLAIM_LRU
+ if (was_nonreclaimable)
+ count_vm_event(NORECL_PGRESCUED);
+#endif
} else {
/*
* Put non-reclaimable pages directly on zone's noreclaim
@@ -494,6 +499,10 @@ int putback_lru_page(struct page *page)
*/
add_page_to_noreclaim_list(page);
mem_cgroup_move_lists(page, LRU_NORECLAIM);
+#ifdef CONFIG_NORECLAIM_LRU
+ if (!was_nonreclaimable)
+ count_vm_event(NORECL_PGCULLED);
+#endif
}
put_page(page); /* drop ref from isolate */
@@ -2384,6 +2393,7 @@ static void check_move_noreclaim_page(st
__dec_zone_state(zone, NR_NORECLAIM);
list_move(&page->lru, &zone->list[l]);
__inc_zone_state(zone, NR_INACTIVE_ANON + l);
+ __count_vm_event(NORECL_PGRESCUED);
} else {
/*
* rotate noreclaim list
@@ -2415,6 +2425,7 @@ void scan_mapping_noreclaim_pages(struct
while (next < end &&
pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) {
int i;
+ int pg_scanned = 0;
zone = NULL;
@@ -2423,6 +2434,7 @@ void scan_mapping_noreclaim_pages(struct
pgoff_t page_index = page->index;
struct zone *pagezone = page_zone(page);
+ pg_scanned++;
if (page_index > next)
next = page_index;
next++;
@@ -2453,6 +2465,8 @@ void scan_mapping_noreclaim_pages(struct
if (zone)
spin_unlock_irq(&zone->lru_lock);
pagevec_release(&pvec);
+
+ count_vm_events(NORECL_PGSCANNED, pg_scanned);
}
}
diff -puN mm/vmstat.c~noreclaim-and-mlocked-pages-vm-events mm/vmstat.c
--- a/mm/vmstat.c~noreclaim-and-mlocked-pages-vm-events
+++ a/mm/vmstat.c
@@ -666,6 +666,18 @@ static const char * const vmstat_text[]
"htlb_buddy_alloc_success",
"htlb_buddy_alloc_fail",
#endif
+
+#ifdef CONFIG_NORECLAIM_LRU
+ "noreclaim_pgs_culled",
+ "noreclaim_pgs_scanned",
+ "noreclaim_pgs_rescued",
+#ifdef CONFIG_NORECLAIM_MLOCK
+ "noreclaim_pgs_mlocked",
+ "noreclaim_pgs_munlocked",
+ "noreclaim_pgs_cleared",
+ "noreclaim_pgs_stranded",
+#endif
+#endif
#endif
};
_
Patches currently in -mm which might be from lee.schermerhorn@xxxxxx are
page-allocator-inlnie-some-__alloc_pages-wrappers.patch
page-allocator-inlnie-some-__alloc_pages-wrappers-fix.patch
vmscan-use-an-indexed-array-for-lru-variables.patch
vmscan-define-page_file_cache-function.patch
vmscan-pageflag-helpers-for-configed-out-flags.patch
vmscan-noreclaim-lru-infrastructure.patch
vmscan-noreclaim-lru-page-statistics.patch
vmscan-ramfs-and-ram-disk-pages-are-non-reclaimable.patch
vmscan-shm_locked-pages-are-non-reclaimable.patch
vmscan-mlocked-pages-are-non-reclaimable.patch
vmscan-downgrade-mmap-sem-while-populating-mlocked-regions.patch
vmscan-handle-mlocked-pages-during-map-remap-unmap.patch
vmscan-mlocked-pages-statistics.patch
vmscan-cull-non-reclaimable-pages-in-fault-path.patch
vmscan-noreclaim-and-mlocked-pages-vm-events.patch
mm-only-vmscan-noreclaim-lru-scan-sysctl.patch
vmscan-mlocked-pages-count-attempts-to-free-mlocked-page.patch
vmscan-noreclaim-lru-and-mlocked-pages-documentation.patch
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