* [PATCH] mm/memcg: check kzalloc_node() return in memcg1_init()
@ 2026-07-21 10:09 Hongfu Li
2026-07-22 0:13 ` Andrew Morton
0 siblings, 1 reply; 3+ messages in thread
From: Hongfu Li @ 2026-07-21 10:09 UTC (permalink / raw)
To: hannes, mhocko, roman.gushchin, shakeel.butt, muchun.song, akpm
Cc: cgroups, linux-mm, linux-kernel, hongfu.li, Hongfu Li
From: Hongfu Li <lihongfu@kylinos.cn>
Add NULL check for per-node kzalloc_node() allocations in memcg1_init().
Skip the NUMA node when allocation fails. All users of
soft_limit_tree.rb_tree_per_node[] safely handle NULL entries, only losing
soft-limit tracking for that node.
Signed-off-by: Hongfu Li <lihongfu@kylinos.cn>
---
mm/memcontrol-v1.c | 2 +++++
1 file changed, 2 insertions(+)
diff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c
index 2dc599484d00..33ea693c9281 100644
--- a/mm/memcontrol-v1.c
+++ b/mm/memcontrol-v1.c
@@ -2566,6 +2566,8 @@ static int __init memcg1_init(void)
struct mem_cgroup_tree_per_node *rtpn;
rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, node);
+ if (!rtpn)
+ continue;
rtpn->rb_root = RB_ROOT;
rtpn->rb_rightmost = NULL;
--
2.54.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] mm/memcg: check kzalloc_node() return in memcg1_init()
2026-07-21 10:09 [PATCH] mm/memcg: check kzalloc_node() return in memcg1_init() Hongfu Li
@ 2026-07-22 0:13 ` Andrew Morton
2026-07-22 6:18 ` Hongfu Li
0 siblings, 1 reply; 3+ messages in thread
From: Andrew Morton @ 2026-07-22 0:13 UTC (permalink / raw)
To: Hongfu Li
Cc: hannes, mhocko, roman.gushchin, shakeel.butt, muchun.song,
cgroups, linux-mm, linux-kernel, Hongfu Li
On Tue, 21 Jul 2026 18:09:16 +0800 Hongfu Li <hongfu.li@linux.dev> wrote:
> From: Hongfu Li <lihongfu@kylinos.cn>
>
> Add NULL check for per-node kzalloc_node() allocations in memcg1_init().
>
> Skip the NUMA node when allocation fails. All users of
> soft_limit_tree.rb_tree_per_node[] safely handle NULL entries, only losing
> soft-limit tracking for that node.
>
> ...
>
> --- a/mm/memcontrol-v1.c
> +++ b/mm/memcontrol-v1.c
> @@ -2566,6 +2566,8 @@ static int __init memcg1_init(void)
> struct mem_cgroup_tree_per_node *rtpn;
>
> rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, node);
> + if (!rtpn)
> + continue;
>
> rtpn->rb_root = RB_ROOT;
> rtpn->rb_rightmost = NULL;
Thanks. We assume that mamory allocations cannot fail within __init
code. Because if they do, the kernel has some ghastly problem and it
cannot possibly run.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] mm/memcg: check kzalloc_node() return in memcg1_init()
2026-07-22 0:13 ` Andrew Morton
@ 2026-07-22 6:18 ` Hongfu Li
0 siblings, 0 replies; 3+ messages in thread
From: Hongfu Li @ 2026-07-22 6:18 UTC (permalink / raw)
To: akpm
Cc: cgroups, hannes, hongfu.li, lihongfu, linux-kernel, linux-mm,
mhocko, muchun.song, roman.gushchin, shakeel.butt
> > rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, node);
> > + if (!rtpn)
> > + continue;
> >
> > rtpn->rb_root = RB_ROOT;
> > rtpn->rb_rightmost = NULL;
>
> Thanks. We assume that mamory allocations cannot fail within __init
> code. Because if they do, the kernel has some ghastly problem and it
> cannot possibly run.
Understood, thanks for the clarification. I'll drop this patch.
Best regards,
Hongfu
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2026-07-22 6:19 UTC | newest]
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2026-07-21 10:09 [PATCH] mm/memcg: check kzalloc_node() return in memcg1_init() Hongfu Li
2026-07-22 0:13 ` Andrew Morton
2026-07-22 6:18 ` Hongfu Li
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