From: Muchun Song <songmuchun@bytedance.com>
To: guro@fb.com, hannes@cmpxchg.org, mhocko@kernel.org,
akpm@linux-foundation.org, shakeelb@google.com,
vdavydov.dev@gmail.com
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
duanxiongchun@bytedance.com, fam.zheng@bytedance.com,
bsingharora@gmail.com, shy828301@gmail.com,
alex.shi@linux.alibaba.com,
Muchun Song <songmuchun@bytedance.com>
Subject: [RFC PATCH v3 06/12] mm: thp: make deferred split queue lock safe when the LRU pages reparented
Date: Wed, 21 Apr 2021 15:00:53 +0800 [thread overview]
Message-ID: <20210421070059.69361-7-songmuchun@bytedance.com> (raw)
In-Reply-To: <20210421070059.69361-1-songmuchun@bytedance.com>
Similar to lruvec lock, we use the same approach to make the lock safe
when the LRU pages reparented.
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
mm/huge_memory.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 05ef9e8f9af5..25025bf988f8 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -497,6 +497,8 @@ static struct deferred_split *lock_split_queue(struct page *page)
struct deferred_split *queue;
struct mem_cgroup *memcg;
+ rcu_read_lock();
+retry:
memcg = page_memcg(compound_head(page));
if (memcg)
queue = &memcg->deferred_split_queue;
@@ -504,6 +506,17 @@ static struct deferred_split *lock_split_queue(struct page *page)
queue = &NODE_DATA(page_to_nid(page))->deferred_split_queue;
spin_lock(&queue->split_queue_lock);
+ if (unlikely(memcg != page_memcg(page))) {
+ spin_unlock(&queue->split_queue_lock);
+ goto retry;
+ }
+
+ /*
+ * Preemption is disabled in the internal of spin_lock, which can serve
+ * as RCU read-side critical sections.
+ */
+ rcu_read_unlock();
+
return queue;
}
@@ -513,6 +526,8 @@ static struct deferred_split *lock_split_queue_irqsave(struct page *page,
struct deferred_split *queue;
struct mem_cgroup *memcg;
+ rcu_read_lock();
+retry:
memcg = page_memcg(compound_head(page));
if (memcg)
queue = &memcg->deferred_split_queue;
@@ -520,6 +535,14 @@ static struct deferred_split *lock_split_queue_irqsave(struct page *page,
queue = &NODE_DATA(page_to_nid(page))->deferred_split_queue;
spin_lock_irqsave(&queue->split_queue_lock, *flags);
+ if (unlikely(memcg != page_memcg(page))) {
+ spin_unlock_irqrestore(&queue->split_queue_lock, *flags);
+ goto retry;
+ }
+
+ /* See the comments in lock_split_queue(). */
+ rcu_read_unlock();
+
return queue;
}
#else
--
2.11.0
next prev parent reply other threads:[~2021-04-21 7:01 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-21 7:00 [RFC PATCH v3 00/12] Use obj_cgroup APIs to charge the LRU pages Muchun Song
2021-04-21 7:00 ` [RFC PATCH v3 01/12] mm: memcontrol: move the objcg infrastructure out of CONFIG_MEMCG_KMEM Muchun Song
2021-05-25 16:27 ` Roman Gushchin
2021-05-26 2:46 ` [External] " Muchun Song
2021-04-21 7:00 ` [RFC PATCH v3 02/12] mm: memcontrol: introduce compact_lock_page_lruvec_irqsave Muchun Song
2021-05-25 17:21 ` Roman Gushchin
2021-05-26 2:49 ` [External] " Muchun Song
2021-04-21 7:00 ` [RFC PATCH v3 03/12] mm: memcontrol: make lruvec lock safe when the LRU pages reparented Muchun Song
2021-05-25 17:21 ` Roman Gushchin
2021-04-21 7:00 ` [RFC PATCH v3 04/12] mm: vmscan: rework move_pages_to_lru() Muchun Song
2021-04-21 7:00 ` [RFC PATCH v3 05/12] mm: thp: introduce lock/unlock_split_queue{_irqsave}() Muchun Song
2021-04-21 7:00 ` Muchun Song [this message]
2021-04-21 7:00 ` [RFC PATCH v3 07/12] mm: memcontrol: make all the callers of page_memcg() safe Muchun Song
2021-04-21 7:00 ` [RFC PATCH v3 08/12] mm: memcontrol: introduce memcg_reparent_ops Muchun Song
2021-05-25 17:46 ` Roman Gushchin
2021-05-26 3:01 ` [External] " Muchun Song
2021-04-21 7:00 ` [RFC PATCH v3 09/12] mm: memcontrol: use obj_cgroup APIs to charge the LRU pages Muchun Song
2021-04-21 7:00 ` [RFC PATCH v3 10/12] mm: memcontrol: rename {un}lock_page_memcg() to {un}lock_page_objcg() Muchun Song
2021-04-21 7:00 ` [RFC PATCH v3 11/12] mm: lru: add VM_BUG_ON_PAGE to lru maintenance function Muchun Song
2021-04-21 7:00 ` [RFC PATCH v3 12/12] mm: lru: use lruvec lock to serialize memcg changes Muchun Song
2021-05-18 13:49 ` [RFC PATCH v3 00/12] Use obj_cgroup APIs to charge the LRU pages Muchun Song
2021-05-18 14:17 ` Roman Gushchin
2021-05-20 3:20 ` [External] " Muchun Song
2021-05-25 17:35 ` Roman Gushchin
2021-05-26 2:41 ` Muchun Song
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