Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1182172

[PATCH -mm v7 1/6] memcg: add page_cgroup_ino helper

Show all headers | View raw

This function returns the inode number of the closest online ancestor of
the memory cgroup a page is charged to. It is required for exporting
information about which page is charged to which cgroup to userspace,
which will be introduced by a following patch.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
---
 include/linux/memcontrol.h |  1 +
 mm/memcontrol.c            | 23 +++++++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 73b02b0a8f60..50069abebc3c 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -116,6 +116,7 @@ static inline bool mm_match_cgroup(struct mm_struct *mm,
 
 extern struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *memcg);
 extern struct cgroup_subsys_state *mem_cgroup_css_from_page(struct page *page);
+extern unsigned long page_cgroup_ino(struct page *page);
 
 struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *,
 				   struct mem_cgroup *,
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index acb93c554f6e..894dc2169979 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -631,6 +631,29 @@ struct cgroup_subsys_state *mem_cgroup_css_from_page(struct page *page)
 	return &memcg->css;
 }
 
+/**
+ * page_cgroup_ino - return inode number of the memcg a page is charged to
+ * @page: the page
+ *
+ * Look up the closest online ancestor of the memory cgroup @page is charged to
+ * and return its inode number or 0 if @page is not charged to any cgroup. It
+ * is safe to call this function without holding a reference to @page.
+ */
+unsigned long page_cgroup_ino(struct page *page)
+{
+	struct mem_cgroup *memcg;
+	unsigned long ino = 0;
+
+	rcu_read_lock();
+	memcg = READ_ONCE(page->mem_cgroup);
+	while (memcg && !(memcg->css.flags & CSS_ONLINE))
+		memcg = parent_mem_cgroup(memcg);
+	if (memcg)
+		ino = cgroup_ino(memcg->css.cgroup);
+	rcu_read_unlock();
+	return ino;
+}
+
 static struct mem_cgroup_per_zone *
 mem_cgroup_page_zoneinfo(struct mem_cgroup *memcg, struct page *page)
 {
-- 
2.1.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

[PATCH -mm v7 0/6] idle memory tracking Vladimir Davydov <vdavydov@parallels.com> - 2015-07-11 16:50 +0200
  [PATCH -mm v7 5/6] proc: add kpageidle file Vladimir Davydov <vdavydov@parallels.com> - 2015-07-11 16:50 +0200
    Re: [PATCH -mm v7 5/6] proc: add kpageidle file Andres Lagar-Cavilla <andreslc@google.com> - 2015-07-14 22:30 +0200
  [PATCH -mm v7 3/6] memcg: zap try_get_mem_cgroup_from_page Vladimir Davydov <vdavydov@parallels.com> - 2015-07-11 16:50 +0200
  [PATCH -mm v7 2/6] hwpoison: use page_cgroup_ino for filtering by memcg Vladimir Davydov <vdavydov@parallels.com> - 2015-07-11 16:50 +0200
  [PATCH -mm v7 6/6] proc: export idle flag via kpageflags Vladimir Davydov <vdavydov@parallels.com> - 2015-07-11 16:50 +0200
  [PATCH -mm v7 4/6] proc: add kpagecgroup file Vladimir Davydov <vdavydov@parallels.com> - 2015-07-11 16:50 +0200
  [PATCH -mm v7 1/6] memcg: add page_cgroup_ino helper Vladimir Davydov <vdavydov@parallels.com> - 2015-07-11 17:00 +0200

csiph-web