Re: [PATCH v4 bpf-next/net 1/5] tcp: Save lock_sock() for memcg in inet_csk_accept().
From: Martin KaFai Lau <martin.lau@linux.dev>
Date: 2025-09-02 18:55:21
Also in:
bpf
On 8/28/25 6:00 PM, Kuniyuki Iwashima wrote:
mem_cgroup_sk_alloc() is called for SCTP before __inet_accept(), so I added the protocol check in __inet_accept(), but this can be removed once SCTP uses sk_clone_lock().
void __inet_accept(struct socket *sock, struct socket *newsock, struct sock *newsk)
{
+ /* TODO: use sk_clone_lock() in SCTP and remove protocol checks */
+ if (mem_cgroup_sockets_enabled &&
+ (!IS_ENABLED(CONFIG_IP_SCTP) ||
+ sk_is_tcp(newsk) || sk_is_mptcp(newsk))) {Instead of protocol check, is it the same as checking "if (mem_cgroup_sockets_enabled && !mem_cgroup_from_sk(newsk))"
+ gfp_t gfp = GFP_KERNEL | __GFP_NOFAIL;
+
+ mem_cgroup_sk_alloc(newsk);
+
+ if (mem_cgroup_from_sk(newsk)) {
+ int amt;
+
+ /* The socket has not been accepted yet, no need
+ * to look at newsk->sk_wmem_queued.
+ */
+ amt = sk_mem_pages(newsk->sk_forward_alloc +
+ atomic_read(&newsk->sk_rmem_alloc));
+ if (amt)
+ mem_cgroup_sk_charge(newsk, amt, gfp);
+ }
+
+ kmem_cache_charge(newsk, gfp);
+ }
+