Move VM_BUG_ON_FOLIO() to cover both the default and MGLRU paths. Also
use a pair of rcu_read_lock() and rcu_read_unlock() within each path,
to improve readability.
This change should not have any side effects.
Signed-off-by: Yu Zhao <yuzhao@xxxxxxxxxx>
Tested-by: Kalesh Singh <kaleshsingh@xxxxxxxxxx>
---
mm/workingset.c | 25 ++++++++++++-------------
1 file changed, 12 insertions(+), 13 deletions(-)
diff --git a/mm/workingset.c b/mm/workingset.c
index a4705e196545..ad181d1b8cf1 100644
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -428,17 +428,17 @@ bool workingset_test_recent(void *shadow, bool file, bool *workingset,
struct pglist_data *pgdat;
unsigned long eviction;
- rcu_read_lock();
-
if (lru_gen_enabled()) {
- bool recent = lru_gen_test_recent(shadow, file,
- &eviction_lruvec, &eviction, workingset);
+ bool recent;
+ rcu_read_lock();
+ recent = lru_gen_test_recent(shadow, file, &eviction_lruvec,
+ &eviction, workingset);
rcu_read_unlock();
return recent;
}
-
+ rcu_read_lock();
unpack_shadow(shadow, &memcgid, &pgdat, &eviction, workingset);
eviction <<= bucket_order;
@@ -459,14 +459,12 @@ bool workingset_test_recent(void *shadow, bool file, bool *workingset,
* configurations instead.
*/
eviction_memcg = mem_cgroup_from_id(memcgid);
- if (!mem_cgroup_disabled() &&
- (!eviction_memcg || !mem_cgroup_tryget(eviction_memcg))) {
- rcu_read_unlock();
+ if (!mem_cgroup_tryget(eviction_memcg))
+ eviction_memcg = NULL;
+ rcu_read_unlock();
+
+ if (!mem_cgroup_disabled() && !eviction_memcg)
return false;
- }
-
- rcu_read_unlock();
-
/*
* Flush stats (and potentially sleep) outside the RCU read section.
*
@@ -544,6 +542,8 @@ void workingset_refault(struct folio *folio, void *shadow)
bool workingset;
long nr;
+ VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);
+
if (lru_gen_enabled()) {
lru_gen_refault(folio, shadow);
return;
@@ -558,7 +558,6 @@ void workingset_refault(struct folio *folio, void *shadow)
* is actually experiencing the refault event. Make sure the folio is
* locked to guarantee folio_memcg() stability throughout.
*/
- VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);
nr = folio_nr_pages(folio);
memcg = folio_memcg(folio);
pgdat = folio_pgdat(folio);
--
2.47.0.338.g60cca15819-goog
