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authorJohannes Weiner <hannes@cmpxchg.org>2026-05-27 23:45:11 +0300
committerAndrew Morton <akpm@linux-foundation.org>2026-06-09 04:21:24 +0300
commit8b98cfe2c52d7492a024b655e0978545845646cb (patch)
tree7c797a6fb006184840593c2000a7d762113b3a98
parent82d8bca1c715e9ed31eaeb5197a0ba00bf8be597 (diff)
downloadlinux-8b98cfe2c52d7492a024b655e0978545845646cb.tar.xz
mm: list_lru: move list dead check to lock_list_lru_of_memcg()
Only the MEMCG variant of lock_list_lru() needs to check if there is a race with cgroup deletion and list reparenting. Move the check to the caller, so that the next patch can unify the lock_list_lru() variants. Link: https://lore.kernel.org/20260527204757.2544958-5-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Reviewed-by: Liam R. Howlett (Oracle) <liam@infradead.org> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Kairui Song <ryncsn@gmail.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mikhail Zaslonko <zaslonko@linux.ibm.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nico Pache <npache@redhat.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Usama Arif <usama.arif@linux.dev> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r--mm/list_lru.c17
1 files changed, 8 insertions, 9 deletions
diff --git a/mm/list_lru.c b/mm/list_lru.c
index 5497034e80f3..7d0523e44010 100644
--- a/mm/list_lru.c
+++ b/mm/list_lru.c
@@ -68,17 +68,12 @@ list_lru_from_memcg_idx(struct list_lru *lru, int nid, int idx)
return &lru->node[nid].lru;
}
-static inline bool lock_list_lru(struct list_lru_one *l, bool irq)
+static inline void lock_list_lru(struct list_lru_one *l, bool irq)
{
if (irq)
spin_lock_irq(&l->lock);
else
spin_lock(&l->lock);
- if (unlikely(READ_ONCE(l->nr_items) == LONG_MIN)) {
- unlock_list_lru(l, irq);
- return false;
- }
- return true;
}
static inline struct list_lru_one *
@@ -90,9 +85,13 @@ lock_list_lru_of_memcg(struct list_lru *lru, int nid,
rcu_read_lock();
again:
l = list_lru_from_memcg_idx(lru, nid, memcg_kmem_id(*memcg));
- if (likely(l) && lock_list_lru(l, irq)) {
- rcu_read_unlock();
- return l;
+ if (likely(l)) {
+ lock_list_lru(l, irq);
+ if (likely(READ_ONCE(l->nr_items) != LONG_MIN)) {
+ rcu_read_unlock();
+ return l;
+ }
+ unlock_list_lru(l, irq);
}
/*
* Caller may simply bail out if raced with reparenting or