[PATCH v3 4/5] sock: Consider memcg pressure when raising sockmem
From: Abel Wu <hidden>
Date: 2023-05-23 09:48:11
Also in:
lkml
Subsystem:
networking [general], networking [sockets], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Kuniyuki Iwashima, Willem de Bruijn, Linus Torvalds
For now __sk_mem_raise_allocated() mainly considers global socket memory pressure and allows to raise if no global pressure observed, including the sockets whose memcgs are in pressure, which might result in longer memcg memstall. So take net-memcg's pressure into consideration when allocating socket memory to alleviate long tail latencies. Signed-off-by: Abel Wu <redacted> --- net/core/sock.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-)
diff --git a/net/core/sock.c b/net/core/sock.c
index 801df091e37a..b899e0b9feda 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c@@ -2976,22 +2976,31 @@ EXPORT_SYMBOL(sk_wait_data); int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind) { bool memcg_charge = mem_cgroup_sockets_enabled && sk->sk_memcg; + bool charged = true, pressured = false; struct proto *prot = sk->sk_prot; - bool charged = true; long allocated; sk_memory_allocated_add(sk, amt); allocated = sk_memory_allocated(sk); - if (memcg_charge && - !(charged = mem_cgroup_charge_skmem(sk->sk_memcg, amt, - gfp_memcg_charge()))) - goto suppress_allocation; + + if (memcg_charge) { + charged = mem_cgroup_charge_skmem(sk->sk_memcg, amt, + gfp_memcg_charge()); + if (!charged) + goto suppress_allocation; + if (mem_cgroup_under_socket_pressure(sk->sk_memcg)) + pressured = true; + } /* Under limit. */ - if (allocated <= sk_prot_mem_limits(sk, 0)) { + if (allocated <= sk_prot_mem_limits(sk, 0)) sk_leave_memory_pressure(sk); + else + pressured = true; + + /* No pressure observed in global/memcg. */ + if (!pressured) return 1; - } /* Under pressure. */ if (allocated > sk_prot_mem_limits(sk, 1))
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2.37.3