Re: [PATCH bpf-next 2/2] bpf: split cgroup_bpf_enabled per attach type
From: Song Liu <song@kernel.org>
Date: 2020-12-21 22:41:56
Also in:
bpf
On Thu, Dec 17, 2020 at 9:26 AM Stanislav Fomichev [off-list ref] wrote:
When we attach any cgroup hook, the rest (even if unused/unattached) start to contribute small overhead. In particular, the one we want to avoid is __cgroup_bpf_run_filter_skb which does two redirections to get to the cgroup and pushes/pulls skb. Let's split cgroup_bpf_enabled to be per-attach to make sure only used attach types trigger. I've dropped some existing high-level cgroup_bpf_enabled in some places because BPF_PROG_CGROUP_XXX_RUN macros usually have another cgroup_bpf_enabled check. I also had to copy-paste BPF_CGROUP_RUN_SA_PROG_LOCK for GETPEERNAME/GETSOCKNAME because type for cgroup_bpf_enabled[type] has to be constant and known at compile time. Signed-off-by: Stanislav Fomichev <redacted>
[...]
quoted hunk ↗ jump to hunk
@@ -252,8 +252,10 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, #define BPF_CGROUP_RUN_PROG_INET6_BIND_LOCK(sk, uaddr) \ BPF_CGROUP_RUN_SA_PROG_LOCK(sk, uaddr, BPF_CGROUP_INET6_BIND, NULL) -#define BPF_CGROUP_PRE_CONNECT_ENABLED(sk) (cgroup_bpf_enabled && \ - sk->sk_prot->pre_connect) +#define BPF_CGROUP_PRE_CONNECT_ENABLED(sk) \ + ((cgroup_bpf_enabled(BPF_CGROUP_INET4_CONNECT) || \ + cgroup_bpf_enabled(BPF_CGROUP_INET6_CONNECT)) && \ + sk->sk_prot->pre_connect)
Patchworks highlighted the following (from checkpatch.pl I guess): CHECK: Macro argument 'sk' may be better as '(sk)' to avoid precedence issues #99: FILE: include/linux/bpf-cgroup.h:255: +#define BPF_CGROUP_PRE_CONNECT_ENABLED(sk) \ + ((cgroup_bpf_enabled(BPF_CGROUP_INET4_CONNECT) || \ + cgroup_bpf_enabled(BPF_CGROUP_INET6_CONNECT)) && \ + sk->sk_prot->pre_connect) Other than, looks good to me. Acked-by: Song Liu <redacted>