The patch titled
mlock: count attempts to free mlocked page
has been added to the -mm tree. Its filename is
mlock-count-attempts-to-free-mlocked-page-2.patch
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The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: mlock: count attempts to free mlocked page
From: Lee Schermerhorn <lee.schermerhorn@xxxxxx>
Allow free of mlock()ed pages. This shouldn't happen, but during
developement, it occasionally did.
This patch allows us to survive that condition, while keeping the
statistics and events correct for debug.
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@xxxxxx>
Signed-off-by: Rik van Riel <riel@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/vmstat.h | 1 +
mm/internal.h | 17 +++++++++++++++++
mm/page_alloc.c | 1 +
mm/vmstat.c | 1 +
4 files changed, 20 insertions(+)
diff -puN include/linux/vmstat.h~mlock-count-attempts-to-free-mlocked-page-2 include/linux/vmstat.h
--- a/include/linux/vmstat.h~mlock-count-attempts-to-free-mlocked-page-2
+++ a/include/linux/vmstat.h
@@ -49,6 +49,7 @@ enum vm_event_item { PGPGIN, PGPGOUT, PS
UNEVICTABLE_PGMUNLOCKED,
UNEVICTABLE_PGCLEARED, /* on COW, page truncate */
UNEVICTABLE_PGSTRANDED, /* unable to isolate on unlock */
+ UNEVICTABLE_MLOCKFREED,
#endif
NR_VM_EVENT_ITEMS
};
diff -puN mm/internal.h~mlock-count-attempts-to-free-mlocked-page-2 mm/internal.h
--- a/mm/internal.h~mlock-count-attempts-to-free-mlocked-page-2
+++ a/mm/internal.h
@@ -146,6 +146,22 @@ static inline void mlock_migrate_page(st
}
}
+/*
+ * free_page_mlock() -- clean up attempts to free and mlocked() page.
+ * Page should not be on lru, so no need to fix that up.
+ * free_pages_check() will verify...
+ */
+static inline void free_page_mlock(struct page *page)
+{
+ if (unlikely(TestClearPageMlocked(page))) {
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __dec_zone_page_state(page, NR_MLOCK);
+ __count_vm_event(UNEVICTABLE_MLOCKFREED);
+ local_irq_restore(flags);
+ }
+}
#else /* CONFIG_UNEVICTABLE_LRU */
static inline int is_mlocked_vma(struct vm_area_struct *v, struct page *p)
@@ -155,6 +171,7 @@ static inline int is_mlocked_vma(struct
static inline void clear_page_mlock(struct page *page) { }
static inline void mlock_vma_page(struct page *page) { }
static inline void mlock_migrate_page(struct page *new, struct page *old) { }
+static inline void free_page_mlock(struct page *page) { }
#endif /* CONFIG_UNEVICTABLE_LRU */
diff -puN mm/page_alloc.c~mlock-count-attempts-to-free-mlocked-page-2 mm/page_alloc.c
--- a/mm/page_alloc.c~mlock-count-attempts-to-free-mlocked-page-2
+++ a/mm/page_alloc.c
@@ -451,6 +451,7 @@ static inline void __free_one_page(struc
static inline int free_pages_check(struct page *page)
{
+ free_page_mlock(page);
if (unlikely(page_mapcount(page) |
(page->mapping != NULL) |
(page_get_page_cgroup(page) != NULL) |
diff -puN mm/vmstat.c~mlock-count-attempts-to-free-mlocked-page-2 mm/vmstat.c
--- a/mm/vmstat.c~mlock-count-attempts-to-free-mlocked-page-2
+++ a/mm/vmstat.c
@@ -672,6 +672,7 @@ static const char * const vmstat_text[]
"unevictable_pgs_munlocked",
"unevictable_pgs_cleared",
"unevictable_pgs_stranded",
+ "unevictable_pgs_mlockfreed",
#endif
#endif
};
_
Patches currently in -mm which might be from lee.schermerhorn@xxxxxx are
vmscan-use-an-indexed-array-for-lru-variables.patch
define-page_file_cache-function.patch
vmscan-split-lru-lists-into-anon-file-sets.patch
pageflag-helpers-for-configed-out-flags.patch
unevictable-lru-infrastructure.patch
unevictable-lru-infrastructure-nommu-fix.patch
unevictable-lru-infrastructure-remember-pages-active-state.patch
unevictable-lru-infrastructure-defer-vm-event-counting.patch
unevictable-infrastructure-lru-add-event-counting-with-statistics.patch
unevictable-lru-page-statistics.patch
ramfs-and-ram-disk-pages-are-unevictable.patch
shm_locked-pages-are-unevictable.patch
shm_locked-pages-are-unevictable-add-event-counts-to-list-scan.patch
mlock-mlocked-pages-are-unevictable.patch
doc-unevictable-lru-and-mlocked-pages-documentation.patch
mlock-downgrade-mmap-sem-while-populating-mlocked-regions.patch
mmap-handle-mlocked-pages-during-map-remap-unmap.patch
vmstat-mlocked-pages-statistics.patch
vmstat-mlocked-pages-statistics-mlocked-pages-add-event-counting-with-statistics.patch
swap-cull-unevictable-pages-in-fault-path.patch
vmscan-unevictable-lru-scan-sysctl.patch
mlock-count-attempts-to-free-mlocked-page-2.patch
mlock-count-attempts-to-free-mlocked-page.patch
--
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