Linux-mm Archive on lore.kernel.org
 help / color / Atom feed
* [PATCH v2] mm/slab.c: add node spinlock protect in __cache_free_alien
@ 2020-07-30  2:52 qiang.zhang
  0 siblings, 0 replies; only message in thread
From: qiang.zhang @ 2020-07-30  2:52 UTC (permalink / raw)
  To: cl, penberg, rientjes, iamjoonsoo.kim, akpm; +Cc: linux-mm, linux-kernel

From: Zhang Qiang <qiang.zhang@windriver.com>

Due to cpu hotplug, the "cpuup_canceled" func be called, it's currently
manipulating the alien cache for the canceled cpu's node and this node
may be the same as the node which node's alien cache being operated in
the "__cache_free_alien" func, so we should add a protect for node's alien
cache in "__cache_free_alien" func.

Fixes: 6731d4f12315 ("slab: Convert to hotplug state machine")
Signed-off-by: Zhang Qiang <qiang.zhang@windriver.com>
---
 v1->v2:
 change submission information and fixes tags.

 mm/slab.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/mm/slab.c b/mm/slab.c
index a89633603b2d..290523c90b4e 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -759,8 +759,10 @@ static int __cache_free_alien(struct kmem_cache *cachep, void *objp,
 
 	n = get_node(cachep, node);
 	STATS_INC_NODEFREES(cachep);
+	spin_lock(&n->list_lock);
 	if (n->alien && n->alien[page_node]) {
 		alien = n->alien[page_node];
+		spin_unlock(&n->list_lock);
 		ac = &alien->ac;
 		spin_lock(&alien->lock);
 		if (unlikely(ac->avail == ac->limit)) {
@@ -769,14 +771,15 @@ static int __cache_free_alien(struct kmem_cache *cachep, void *objp,
 		}
 		ac->entry[ac->avail++] = objp;
 		spin_unlock(&alien->lock);
-		slabs_destroy(cachep, &list);
 	} else {
+		spin_unlock(&n->list_lock);
 		n = get_node(cachep, page_node);
 		spin_lock(&n->list_lock);
 		free_block(cachep, &objp, 1, page_node, &list);
 		spin_unlock(&n->list_lock);
-		slabs_destroy(cachep, &list);
 	}
+
+	slabs_destroy(cachep, &list);
 	return 1;
 }
 
-- 
2.26.2



^ permalink raw reply	[flat|nested] only message in thread

only message in thread, back to index

Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-07-30  2:52 [PATCH v2] mm/slab.c: add node spinlock protect in __cache_free_alien qiang.zhang

Linux-mm Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-mm/0 linux-mm/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-mm linux-mm/ https://lore.kernel.org/linux-mm \
		linux-mm@kvack.org
	public-inbox-index linux-mm

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kvack.linux-mm


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git