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From: Kuniyuki Iwashima To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Neal Cardwell , Paolo Abeni , Willem de Bruijn , Matthieu Baerts , Mat Martineau , Johannes Weiner , Michal Hocko , Roman Gushchin , Shakeel Butt , Andrew Morton , "=?UTF-8?q?Michal=20Koutn=C3=BD?=" , Tejun Heo Cc: Simon Horman , Geliang Tang , Muchun Song , Mina Almasry , Kuniyuki Iwashima , Kuniyuki Iwashima , netdev@vger.kernel.org, mptcp@lists.linux.dev, cgroups@vger.kernel.org, linux-mm@kvack.org Content-Type: text/plain; charset="UTF-8" X-Stat-Signature: ohit5bond4uya39ydhdsph4tay7ui9ew X-Rspam-User: X-Rspamd-Queue-Id: B04BF40008 X-Rspamd-Server: rspam01 X-HE-Tag: 1755289056-751890 X-HE-Meta: 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 s1gH9lf4 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: When sk_alloc() allocates a socket, mem_cgroup_sk_alloc() sets sk->sk_memcg based on the current task. MPTCP subflow socket creation is triggered from userspace or an in-kernel worker. In the latter case, sk->sk_memcg is not what we want. So, we fix it up from the parent socket's sk->sk_memcg in mptcp_attach_cgroup(). Although the code is placed under #ifdef CONFIG_MEMCG, it is buried under #ifdef CONFIG_SOCK_CGROUP_DATA. The two configs are orthogonal. If CONFIG_MEMCG is enabled without CONFIG_SOCK_CGROUP_DATA, the subflow's memory usage is not charged correctly. Let's move the code out of the wrong ifdef guard. Note that sk->sk_memcg is freed in sk_prot_free() and the parent sk holds the refcnt of memcg->css here, so we don't need to use css_tryget(). Fixes: 3764b0c5651e3 ("mptcp: attach subflow socket to parent cgroup") Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Acked-by: Matthieu Baerts (NGI0) --- include/linux/memcontrol.h | 6 ++++++ mm/memcontrol.c | 13 +++++++++++++ net/mptcp/subflow.c | 11 +++-------- 3 files changed, 22 insertions(+), 8 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 785173aa0739..25921fbec685 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -1604,6 +1604,7 @@ extern struct static_key_false memcg_sockets_enabled_key; #define mem_cgroup_sockets_enabled static_branch_unlikely(&memcg_sockets_enabled_key) void mem_cgroup_sk_alloc(struct sock *sk); void mem_cgroup_sk_free(struct sock *sk); +void mem_cgroup_sk_inherit(const struct sock *sk, struct sock *newsk); #if BITS_PER_LONG < 64 static inline void mem_cgroup_set_socket_pressure(struct mem_cgroup *memcg) @@ -1661,6 +1662,11 @@ void reparent_shrinker_deferred(struct mem_cgroup *memcg); #define mem_cgroup_sockets_enabled 0 static inline void mem_cgroup_sk_alloc(struct sock *sk) { }; static inline void mem_cgroup_sk_free(struct sock *sk) { }; + +static inline void mem_cgroup_sk_inherit(const struct sock *sk, struct sock *newsk) +{ +} + static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg) { return false; diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 8dd7fbed5a94..46713b9ece06 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5024,6 +5024,19 @@ void mem_cgroup_sk_free(struct sock *sk) css_put(&sk->sk_memcg->css); } +void mem_cgroup_sk_inherit(const struct sock *sk, struct sock *newsk) +{ + if (sk->sk_memcg == newsk->sk_memcg) + return; + + mem_cgroup_sk_free(newsk); + + if (sk->sk_memcg) + css_get(&sk->sk_memcg->css); + + newsk->sk_memcg = sk->sk_memcg; +} + /** * mem_cgroup_charge_skmem - charge socket memory * @memcg: memcg to charge diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 3f1b62a9fe88..c8a7e4b59db1 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -1717,19 +1717,14 @@ static void mptcp_attach_cgroup(struct sock *parent, struct sock *child) /* only the additional subflows created by kworkers have to be modified */ if (cgroup_id(sock_cgroup_ptr(parent_skcd)) != cgroup_id(sock_cgroup_ptr(child_skcd))) { -#ifdef CONFIG_MEMCG - struct mem_cgroup *memcg = parent->sk_memcg; - - mem_cgroup_sk_free(child); - if (memcg && css_tryget(&memcg->css)) - child->sk_memcg = memcg; -#endif /* CONFIG_MEMCG */ - cgroup_sk_free(child_skcd); *child_skcd = *parent_skcd; cgroup_sk_clone(child_skcd); } #endif /* CONFIG_SOCK_CGROUP_DATA */ + + if (mem_cgroup_sockets_enabled) + mem_cgroup_sk_inherit(parent, child); } static void mptcp_subflow_ops_override(struct sock *ssk) -- 2.51.0.rc1.163.g2494970778-goog