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authorDaisuke Nishimura <nishimura@mxp.nes.nec.co.jp>2011-03-23 16:42:25 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-03-23 19:46:25 -0700
commitf212ad7cf9c73f8a7fa160e223dcb3f074441a72 (patch)
tree95789ef7ce662e86a3e4aded5dfb97c51dc7b0a0 /mm
parentaf4a662144884a7dbb19acbef70878b3b955f928 (diff)
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memcg: add memcg sanity checks at allocating and freeing pages
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@mxp.nes.nec.co.jp> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Minchan Kim <minchan.kim@gmail.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/memcontrol.c46
-rw-r--r--mm/page_alloc.c8
2 files changed, 52 insertions, 2 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 3a2d54b..0356cb6 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3046,6 +3046,52 @@ int mem_cgroup_shmem_charge_fallback(struct page *page,
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) {
+ int ret = -1;
+ char *path;
+
+ printk(KERN_ALERT "pc:%p pc->flags:%lx pc->mem_cgroup:%p",
+ pc, pc->flags, pc->mem_cgroup);
+
+ path = kmalloc(PATH_MAX, GFP_KERNEL);
+ if (path) {
+ rcu_read_lock();
+ ret = cgroup_path(pc->mem_cgroup->css.cgroup,
+ path, PATH_MAX);
+ rcu_read_unlock();
+ }
+
+ printk(KERN_CONT "(%s)\n",
+ (ret < 0) ? "cannot get the path" : path);
+ kfree(path);
+ }
+}
+#endif
+
static DEFINE_MUTEX(set_limit_mutex);
static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 3a58221..8e5726a 100644
--- a/mm/page_alloc.c
+++ b/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(struct page *page)
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;
}
@@ -754,7 +756,8 @@ static inline int check_new_page(struct page *page)
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;
}
@@ -5684,4 +5687,5 @@ 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);
}