diff mbox series

[1/9] mm: workingset: don't drop refault information prematurely

Message ID 20180801151958.32590-2-hannes@cmpxchg.org (mailing list archive)
State New, archived
Headers show
Series psi: pressure stall information for CPU, memory, and IO v3 | expand

Commit Message

Johannes Weiner Aug. 1, 2018, 3:19 p.m. UTC 
From: Johannes Weiner <jweiner@fb.com>

If we keep just enough refault information to match the CURRENT page
cache during reclaim time, we could lose a lot of events when there is
only a temporary spike in non-cache memory consumption that pushes out
all the cache. Once cache comes back, we won't see those refaults.
They might not be actionable for LRU aging, but we want to know about
them for measuring memory pressure.

Signed-off-by: Johannes Weiner <jweiner@fb.com>
---
 mm/workingset.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)
diff mbox series

Patch

diff --git a/mm/workingset.c b/mm/workingset.c
index 40ee02c83978..53759a3cf99a 100644
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -364,7 +364,7 @@  static unsigned long count_shadow_nodes(struct shrinker *shrinker,
 {
 	unsigned long max_nodes;
 	unsigned long nodes;
-	unsigned long cache;
+	unsigned long pages;
 
 	/* list_lru lock nests inside the IRQ-safe i_pages lock */
 	local_irq_disable();
@@ -393,14 +393,14 @@  static unsigned long count_shadow_nodes(struct shrinker *shrinker,
 	 *
 	 * PAGE_SIZE / radix_tree_nodes / node_entries * 8 / PAGE_SIZE
 	 */
-	if (sc->memcg) {
-		cache = mem_cgroup_node_nr_lru_pages(sc->memcg, sc->nid,
-						     LRU_ALL_FILE);
-	} else {
-		cache = node_page_state(NODE_DATA(sc->nid), NR_ACTIVE_FILE) +
-			node_page_state(NODE_DATA(sc->nid), NR_INACTIVE_FILE);
-	}
-	max_nodes = cache >> (RADIX_TREE_MAP_SHIFT - 3);
+#ifdef CONFIG_MEMCG
+	if (sc->memcg)
+		pages = page_counter_read(&sc->memcg->memory);
+	else
+#endif
+		pages = node_present_pages(sc->nid);
+
+	max_nodes = pages >> (RADIX_TREE_MAP_SHIFT - 3);
 
 	if (nodes <= max_nodes)
 		return 0;