From 68d48e6a2df575b935edd420396c3cb8b6aa6ad3 Mon Sep 17 00:00:00 2001
From: Johannes Weiner <hannes@cmpxchg.org>
Date: Fri, 26 Oct 2018 15:06:39 -0700
Subject: [PATCH] mm: workingset: add vmstat counter for shadow nodes
Make it easier to catch bugs in the shadow node shrinker by adding a
counter for the shadow nodes in circulation.
[akpm@linux-foundation.org: assert that irqs are disabled, for __inc_lruvec_page_state()]
[akpm@linux-foundation.org: s/WARN_ON_ONCE/VM_WARN_ON_ONCE/, per Johannes]
Link: http://lkml.kernel.org/r/20181009184732.762-4-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
include/linux/mmzone.h | 1 +
mm/vmstat.c | 1 +
mm/workingset.c | 14 ++++++++++++--
3 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index ba51d5bf7af10..9f0caccd58332 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -161,6 +161,7 @@ enum node_stat_item {
NR_SLAB_UNRECLAIMABLE,
NR_ISOLATED_ANON, /* Temporary isolated pages from anon lru */
NR_ISOLATED_FILE, /* Temporary isolated pages from file lru */
+ WORKINGSET_NODES,
WORKINGSET_REFAULT,
WORKINGSET_ACTIVATE,
WORKINGSET_RESTORE,
diff --git a/mm/vmstat.c b/mm/vmstat.c
index d918f6192d15a..dab53430f63c2 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1143,6 +1143,7 @@ const char * const vmstat_text[] = {
"nr_slab_unreclaimable",
"nr_isolated_anon",
"nr_isolated_file",
+ "workingset_nodes",
"workingset_refault",
"workingset_activate",
"workingset_restore",
diff --git a/mm/workingset.c b/mm/workingset.c
index 5a72c9d5e195a..7e6ef312cea59 100644
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -377,12 +377,20 @@ void workingset_update_node(struct radix_tree_node *node)
* already where they should be. The list_empty() test is safe
* as node->private_list is protected by the i_pages lock.
*/
+ VM_WARN_ON_ONCE(!irqs_disabled()); /* For __inc_lruvec_page_state */
+
if (node->count && node->count == node->exceptional) {
- if (list_empty(&node->private_list))
+ if (list_empty(&node->private_list)) {
list_lru_add(&shadow_nodes, &node->private_list);
+ __inc_lruvec_page_state(virt_to_page(node),
+ WORKINGSET_NODES);
+ }
} else {
- if (!list_empty(&node->private_list))
+ if (!list_empty(&node->private_list)) {
list_lru_del(&shadow_nodes, &node->private_list);
+ __dec_lruvec_page_state(virt_to_page(node),
+ WORKINGSET_NODES);
+ }
}
}
@@ -473,6 +481,8 @@ static enum lru_status shadow_lru_isolate(struct list_head *item,
}
list_lru_isolate(lru, item);
+ __dec_lruvec_page_state(virt_to_page(node), WORKINGSET_NODES);
+
spin_unlock(lru_lock);
/*
--
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