The patch titled
memcg: add memcg sanity checks at allocating and freeing pages
has been added to the -mm tree. Its filename is
memcg-add-memcg-sanity-checks-at-allocating-and-freeing-pages.patch
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------------------------------------------------------
Subject: memcg: add memcg sanity checks at allocating and freeing pages
From: Daisuke Nishimura <nishimura@xxxxxxxxxxxxxxxxx>
Add checks at allocating or freeing a page whether the page is used (iow,
charged) from the view point of memcg.
This check may be useful in debugging a problem and we did similar checks
before the commit 52d4b9ac(memcg: allocate all page_cgroup at boot).
This patch adds some overheads at allocating or freeing memory, so it's
enabled only when CONFIG_DEBUG_VM is enabled.
Signed-off-by: Daisuke Nishimura <nishimura@xxxxxxxxxxxxxxxxx>
Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx>
Cc: Minchan Kim <minchan.kim@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/memcontrol.h | 17 +++++++++++++++++
mm/memcontrol.c | 30 ++++++++++++++++++++++++++++++
mm/page_alloc.c | 8 ++++++--
3 files changed, 53 insertions(+), 2 deletions(-)
diff -puN include/linux/memcontrol.h~memcg-add-memcg-sanity-checks-at-allocating-and-freeing-pages include/linux/memcontrol.h
--- a/include/linux/memcontrol.h~memcg-add-memcg-sanity-checks-at-allocating-and-freeing-pages
+++ a/include/linux/memcontrol.h
@@ -150,6 +150,10 @@ u64 mem_cgroup_get_limit(struct mem_cgro
void mem_cgroup_split_huge_fixup(struct page *head, struct page *tail);
#endif
+#ifdef CONFIG_DEBUG_VM
+bool mem_cgroup_bad_page_check(struct page *page);
+void mem_cgroup_print_bad_page(struct page *page);
+#endif
#else /* CONFIG_CGROUP_MEM_RES_CTLR */
struct mem_cgroup;
@@ -346,5 +350,18 @@ static inline void mem_cgroup_split_huge
#endif /* CONFIG_CGROUP_MEM_CONT */
+#if !defined(CONFIG_CGROUP_MEM_RES_CTLR) || !defined(CONFIG_DEBUG_VM)
+static inline bool
+mem_cgroup_bad_page_check(struct page *page)
+{
+ return false;
+}
+
+static inline void
+mem_cgroup_print_bad_page(struct page *page)
+{
+}
+#endif
+
#endif /* _LINUX_MEMCONTROL_H */
diff -puN mm/memcontrol.c~memcg-add-memcg-sanity-checks-at-allocating-and-freeing-pages mm/memcontrol.c
--- a/mm/memcontrol.c~memcg-add-memcg-sanity-checks-at-allocating-and-freeing-pages
+++ a/mm/memcontrol.c
@@ -3020,6 +3020,36 @@ int mem_cgroup_shmem_charge_fallback(str
return ret;
}
+#ifdef CONFIG_DEBUG_VM
+static struct page_cgroup *lookup_page_cgroup_used(struct page *page)
+{
+ struct page_cgroup *pc;
+
+ pc = lookup_page_cgroup(page);
+ if (likely(pc) && PageCgroupUsed(pc))
+ return pc;
+ return NULL;
+}
+
+bool mem_cgroup_bad_page_check(struct page *page)
+{
+ if (mem_cgroup_disabled())
+ return false;
+
+ return lookup_page_cgroup_used(page) != NULL;
+}
+
+void mem_cgroup_print_bad_page(struct page *page)
+{
+ struct page_cgroup *pc;
+
+ pc = lookup_page_cgroup_used(page);
+ if (pc)
+ printk(KERN_ALERT "pc:%p pc->flags:%ld pc->mem_cgroup:%p\n",
+ pc, pc->flags, pc->mem_cgroup);
+}
+#endif
+
static DEFINE_MUTEX(set_limit_mutex);
static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
diff -puN mm/page_alloc.c~memcg-add-memcg-sanity-checks-at-allocating-and-freeing-pages mm/page_alloc.c
--- a/mm/page_alloc.c~memcg-add-memcg-sanity-checks-at-allocating-and-freeing-pages
+++ a/mm/page_alloc.c
@@ -53,6 +53,7 @@
#include <linux/compaction.h>
#include <trace/events/kmem.h>
#include <linux/ftrace_event.h>
+#include <linux/memcontrol.h>
#include <asm/tlbflush.h>
#include <asm/div64.h>
@@ -565,7 +566,8 @@ static inline int free_pages_check(struc
if (unlikely(page_mapcount(page) |
(page->mapping != NULL) |
(atomic_read(&page->_count) != 0) |
- (page->flags & PAGE_FLAGS_CHECK_AT_FREE))) {
+ (page->flags & PAGE_FLAGS_CHECK_AT_FREE) |
+ (mem_cgroup_bad_page_check(page)))) {
bad_page(page);
return 1;
}
@@ -750,7 +752,8 @@ static inline int check_new_page(struct
if (unlikely(page_mapcount(page) |
(page->mapping != NULL) |
(atomic_read(&page->_count) != 0) |
- (page->flags & PAGE_FLAGS_CHECK_AT_PREP))) {
+ (page->flags & PAGE_FLAGS_CHECK_AT_PREP) |
+ (mem_cgroup_bad_page_check(page)))) {
bad_page(page);
return 1;
}
@@ -5687,4 +5690,5 @@ void dump_page(struct page *page)
page, atomic_read(&page->_count), page_mapcount(page),
page->mapping, page->index);
dump_page_flags(page->flags);
+ mem_cgroup_print_bad_page(page);
}
_
Patches currently in -mm which might be from nishimura@xxxxxxxxxxxxxxxxx are
origin.patch
memsw-remove-noswapaccount-kernel-parameter.patch
memcg-fix-ugly-initialization-of-return-value-is-in-caller.patch
memcg-soft-limit-reclaim-should-end-at-limit-not-below.patch
memcg-simplify-the-way-memory-limits-are-checked.patch
memcg-remove-unused-page-flag-bitfield-defines.patch
memcg-remove-impossible-conditional-when-committing.patch
memcg-remove-null-check-from-lookup_page_cgroup-result.patch
memcg-add-memcg-sanity-checks-at-allocating-and-freeing-pages.patch
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