1 files changed, 52 insertions, 15 deletions

diff --git a/mm/workingset.c b/mm/workingset.c
index e8212123c1c3..474186b76ced 100644
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -213,28 +213,53 @@ static void unpack_shadow(void *shadow, int *memcgidp, pg_data_t **pgdat,
 	*workingsetp = workingset;
 }
 
+static void advance_inactive_age(struct mem_cgroup *memcg, pg_data_t *pgdat)
+{
+	/*
+	 * Reclaiming a cgroup means reclaiming all its children in a
+	 * round-robin fashion. That means that each cgroup has an LRU
+	 * order that is composed of the LRU orders of its child
+	 * cgroups; and every page has an LRU position not just in the
+	 * cgroup that owns it, but in all of that group's ancestors.
+	 *
+	 * So when the physical inactive list of a leaf cgroup ages,
+	 * the virtual inactive lists of all its parents, including
+	 * the root cgroup's, age as well.
+	 */
+	do {
+		struct lruvec *lruvec;
+
+		lruvec = mem_cgroup_lruvec(memcg, pgdat);
+		atomic_long_inc(&lruvec->inactive_age);
+	} while (memcg && (memcg = parent_mem_cgroup(memcg)));
+}
+
 /**
  * workingset_eviction - note the eviction of a page from memory
+ * @target_memcg: the cgroup that is causing the reclaim
  * @page: the page being evicted
  *
  * Returns a shadow entry to be stored in @page->mapping->i_pages in place
  * of the evicted @page so that a later refault can be detected.
  */
-void *workingset_eviction(struct page *page)
+void *workingset_eviction(struct page *page, struct mem_cgroup *target_memcg)
 {
 	struct pglist_data *pgdat = page_pgdat(page);
-	struct mem_cgroup *memcg = page_memcg(page);
-	int memcgid = mem_cgroup_id(memcg);
 	unsigned long eviction;
 	struct lruvec *lruvec;
+	int memcgid;
 
 	/* Page is fully exclusive and pins page->mem_cgroup */
 	VM_BUG_ON_PAGE(PageLRU(page), page);
 	VM_BUG_ON_PAGE(page_count(page), page);
 	VM_BUG_ON_PAGE(!PageLocked(page), page);
 
-	lruvec = mem_cgroup_lruvec(memcg, pgdat);
-	eviction = atomic_long_inc_return(&lruvec->inactive_age);
+	advance_inactive_age(page_memcg(page), pgdat);
+
+	lruvec = mem_cgroup_lruvec(target_memcg, pgdat);
+	/* XXX: target_memcg can be NULL, go through lruvec */
+	memcgid = mem_cgroup_id(lruvec_memcg(lruvec));
+	eviction = atomic_long_read(&lruvec->inactive_age);
 	return pack_shadow(memcgid, pgdat, eviction, PageWorkingset(page));
 }
 
@@ -244,10 +269,13 @@ void *workingset_eviction(struct page *page)
  * @shadow: shadow entry of the evicted page
  *
  * Calculates and evaluates the refault distance of the previously
- * evicted page in the context of the node it was allocated in.
+ * evicted page in the context of the node and the memcg whose memory
+ * pressure caused the eviction.
  */
 void workingset_refault(struct page *page, void *shadow)
 {
+	struct mem_cgroup *eviction_memcg;
+	struct lruvec *eviction_lruvec;
 	unsigned long refault_distance;
 	struct pglist_data *pgdat;
 	unsigned long active_file;
@@ -277,12 +305,12 @@ void workingset_refault(struct page *page, void *shadow)
 	 * would be better if the root_mem_cgroup existed in all
 	 * configurations instead.
 	 */
-	memcg = mem_cgroup_from_id(memcgid);
-	if (!mem_cgroup_disabled() && !memcg)
+	eviction_memcg = mem_cgroup_from_id(memcgid);
+	if (!mem_cgroup_disabled() && !eviction_memcg)
 		goto out;
-	lruvec = mem_cgroup_lruvec(memcg, pgdat);
-	refault = atomic_long_read(&lruvec->inactive_age);
-	active_file = lruvec_lru_size(lruvec, LRU_ACTIVE_FILE, MAX_NR_ZONES);
+	eviction_lruvec = mem_cgroup_lruvec(eviction_memcg, pgdat);
+	refault = atomic_long_read(&eviction_lruvec->inactive_age);
+	active_file = lruvec_page_state(eviction_lruvec, NR_ACTIVE_FILE);
 
 	/*
 	 * Calculate the refault distance
@@ -302,6 +330,17 @@ void workingset_refault(struct page *page, void *shadow)
 	 */
 	refault_distance = (refault - eviction) & EVICTION_MASK;
 
+	/*
+	 * The activation decision for this page is made at the level
+	 * where the eviction occurred, as that is where the LRU order
+	 * during page reclaim is being determined.
+	 *
+	 * However, the cgroup that will own the page is the one that
+	 * is actually experiencing the refault event.
+	 */
+	memcg = page_memcg(page);
+	lruvec = mem_cgroup_lruvec(memcg, pgdat);
+
 	inc_lruvec_state(lruvec, WORKINGSET_REFAULT);
 
 	/*
@@ -313,7 +352,7 @@ void workingset_refault(struct page *page, void *shadow)
 		goto out;
 
 	SetPageActive(page);
-	atomic_long_inc(&lruvec->inactive_age);
+	advance_inactive_age(memcg, pgdat);
 	inc_lruvec_state(lruvec, WORKINGSET_ACTIVATE);
 
 	/* Page was active prior to eviction */
@@ -332,7 +371,6 @@ out:
 void workingset_activation(struct page *page)
 {
 	struct mem_cgroup *memcg;
-	struct lruvec *lruvec;
 
 	rcu_read_lock();
 	/*
@@ -345,8 +383,7 @@ void workingset_activation(struct page *page)
 	memcg = page_memcg_rcu(page);
 	if (!mem_cgroup_disabled() && !memcg)
 		goto out;
-	lruvec = mem_cgroup_lruvec(memcg, page_pgdat(page));
-	atomic_long_inc(&lruvec->inactive_age);
+	advance_inactive_age(memcg, page_pgdat(page));
 out:
 	rcu_read_unlock();
 }