On Tue, Sep 2, 2025 at 1:17 PM Martin KaFai Lau <martin.lau@xxxxxxxxx> wrote:
>
> On 8/28/25 6:00 PM, Kuniyuki Iwashima wrote:
> > +static inline bool sk_should_enter_memory_pressure(struct sock *sk)
> > +{
> > + return !mem_cgroup_sk_enabled(sk) || !mem_cgroup_sk_isolated(sk);
> > +}
> > +
> > static inline long
> > proto_memory_allocated(const struct proto *prot)
> > {
>
> > @@ -3154,8 +3158,11 @@ bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
> > if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
> > return true;
> >
> > - sk_enter_memory_pressure(sk);
> > + if (sk_should_enter_memory_pressure(sk))
> > + sk_enter_memory_pressure(sk);
> > +
> > sk_stream_moderate_sndbuf(sk);
> > +
> > return false;
> > }
>
> > diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
> > index 71a956fbfc55..dcbd49e2f8af 100644
> > --- a/net/ipv4/tcp.c
> > +++ b/net/ipv4/tcp.c
> > @@ -908,7 +908,8 @@ struct sk_buff *tcp_stream_alloc_skb(struct sock *sk, gfp_t gfp,
> > }
> > __kfree_skb(skb);
> > } else {
> > - sk->sk_prot->enter_memory_pressure(sk);
> > + if (sk_should_enter_memory_pressure(sk))
> > + tcp_enter_memory_pressure(sk);
>
> This change from sk_prot->enter_memory_pressure to tcp_enter_memory_pressure
> looks fine. A qq / nit, have you thought about checking
> sk_should_enter_memory_pressure inside the tcp_enter_memory_pressure(sk) /
> sk_enter_memory_pressure(sk) ?
Yes, I wanted to centralise the check to sk_enter_memory_pressure(),
but it calls tcp_enter_memory_pressure() (or sctp one) and they are also
called directly, so I finally placed the check outside of the functions.
>
> Other changes of patch 4 lgtm.
>
> Shakeel, you have ack-ed patch 1. Will you take a look at patch 3 and patch 4 also?
>
> > sk_stream_moderate_sndbuf(sk);
> > }
>
> > @@ -1016,7 +1017,7 @@ static void mptcp_enter_memory_pressure(struct sock *sk)
> > mptcp_for_each_subflow(msk, subflow) {
> > struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
> >
> > - if (first)
> > + if (first && sk_should_enter_memory_pressure(ssk))
> > tcp_enter_memory_pressure(ssk);
> > sk_stream_moderate_sndbuf(ssk);
> >
> > diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
> > index f672a62a9a52..6696ef837116 100644
> > --- a/net/tls/tls_device.c
> > +++ b/net/tls/tls_device.c
> > @@ -35,6 +35,7 @@
> > #include <linux/netdevice.h>
> > #include <net/dst.h>
> > #include <net/inet_connection_sock.h>
> > +#include <net/proto_memory.h>
> > #include <net/tcp.h>
> > #include <net/tls.h>
> > #include <linux/skbuff_ref.h>
> > @@ -371,7 +372,8 @@ static int tls_do_allocation(struct sock *sk,
> > if (!offload_ctx->open_record) {
> > if (unlikely(!skb_page_frag_refill(prepend_size, pfrag,
> > sk->sk_allocation))) {
> > - READ_ONCE(sk->sk_prot)->enter_memory_pressure(sk);
> > + if (sk_should_enter_memory_pressure(sk))
> > + READ_ONCE(sk->sk_prot)->enter_memory_pressure(sk);
> > sk_stream_moderate_sndbuf(sk);
> > return -ENOMEM;
> > }
>
