On 5/1/24 12:43 AM, Miao Xu wrote:
This patch adds a selftest to show the usage of the new arguments in
cong_control. For simplicity's sake, the testing example reuses cubic's
kernel functions.
Jakub, is it ok to target the set for the bpf-next?
The bpf_tcp_ca test failed (Jakub also mentioned). The progs/tcp_ca_kfunc.c
requires changes. The func signature of bbr_main and the BPF_PROG(cong_control,
...) has to be adjusted.
Since it needs a respin, a few nits.
Please add "selftests/bpf:" to the subject line of this patch 3. I think Patch 1
can use "tcp:" and patch 2 can use "bpf: tcp:" also.
Please also add a cover letter, git format-patch --cover-letter ...
[ ... ]
+void BPF_STRUCT_OPS(bpf_cubic_cong_control, struct sock *sk, __u32 ack, int flag,
+ const struct rate_sample *rs)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+
+ if (((1<<TCP_CA_CWR) | (1<<TCP_CA_Recovery)) &
+ (1 << inet_csk(sk)->icsk_ca_state)) {
+ /* Reduce cwnd if state mandates */
+ tcp_cwnd_reduction(sk, rs->acked_sacked, rs->losses, flag);
+
+ if (!before(tp->snd_una, tp->high_seq)) {
+ /* Reset cwnd to ssthresh in CWR or Recovery (unless it's undone) */
+ if (tp->snd_ssthresh < TCP_INFINITE_SSTHRESH &&
+ inet_csk(sk)->icsk_ca_state == TCP_CA_CWR) {
+ tp->snd_cwnd = tp->snd_ssthresh;
+ tp->snd_cwnd_stamp = tcp_jiffies32;
+ }
+ // __cwnd_event(sk, CA_EVENT_COMPLETE_CWR);
Remove the commented out code.
+ }
+ } else if (tcp_may_raise_cwnd(sk, flag)) {
+ /* Advance cwnd if state allows */
+ cubictcp_cong_avoid(sk, ack, rs->acked_sacked);
+ tp->snd_cwnd_stamp = tcp_jiffies32;
+ }
+
+ tcp_update_pacing_rate(sk);
+}
+
+__u32 BPF_STRUCT_OPS(bpf_cubic_recalc_ssthresh, struct sock *sk)
+{
+ return cubictcp_recalc_ssthresh(sk);
+}
+
+void BPF_STRUCT_OPS(bpf_cubic_state, struct sock *sk, __u8 new_state)
+{
+ cubictcp_state(sk, new_state);
+}
+
+void BPF_STRUCT_OPS(bpf_cubic_acked, struct sock *sk,
+ const struct ack_sample *sample)
+{
+ cubictcp_acked(sk, sample);
+}
+
+__u32 BPF_STRUCT_OPS(bpf_cubic_undo_cwnd, struct sock *sk)
+{
+ return tcp_reno_undo_cwnd(sk);
+}
+
+
+SEC(".struct_ops")
+struct tcp_congestion_ops cubic = {
+ .init = (void *)bpf_cubic_init,
+ .ssthresh = (void *)bpf_cubic_recalc_ssthresh,
+ .cong_control = (void *)bpf_cubic_cong_control,
+ .set_state = (void *)bpf_cubic_state,
+ .undo_cwnd = (void *)bpf_cubic_undo_cwnd,
+ .cwnd_event = (void *)bpf_cubic_cwnd_event,
+ .pkts_acked = (void *)bpf_cubic_acked,
+ .name = "bpf_cubic",
nit. It has the same name as the tcp-cc in bpf_cubic.c. Rename it to
"bpf_cc_cubic" ?
