selftests/bpf: do not hardcode target rate in test_tc_edt BPF program

test_tc_edt currently defines the target rate in both the userspace and
BPF parts. This value could be defined once in the userspace part if we
make it able to configure the BPF program before starting the test.

Add a target_rate variable in the BPF part, and make the userspace part
set it to the desired rate before attaching the shaping program.

Signed-off-by: Alexis Lothoré (eBPF Foundation) <alexis.lothore@bootlin.com>
Link: https://lore.kernel.org/r/20251128-tc_edt-v2-4-26db48373e73@bootlin.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/tools/testing/selftests/bpf/prog_tests/test_tc_edt.c b/tools/testing/selftests/bpf/prog_tests/test_tc_edt.c
index 9ba69398eec49cd59428abdab19d043ae7cffb4d..462512fb191f1c88da9440221dc840c9864301ff 100644 (file)
--- a/tools/testing/selftests/bpf/prog_tests/test_tc_edt.c
+++ b/tools/testing/selftests/bpf/prog_tests/test_tc_edt.c
@@ -66,6 +66,7 @@ static int setup(struct test_tc_edt *skel)
        ret = tc_prog_attach("veth2", -1, bpf_program__fd(skel->progs.tc_prog));
        if (!ASSERT_OK(ret, "attach bpf prog"))
                goto fail_close_server_ns;
+       skel->bss->target_rate = TARGET_RATE_MBPS * 1000 * 1000;
        close_netns(nstoken_server);
        close_netns(nstoken_client);
 

diff --git a/tools/testing/selftests/bpf/progs/test_tc_edt.c b/tools/testing/selftests/bpf/progs/test_tc_edt.c
index d31058cf4ecac36b8edbc4424a583001bcfa2da2..4f6f03122d61d2367eadc977c776c97006b8f216 100644 (file)
--- a/tools/testing/selftests/bpf/progs/test_tc_edt.c
+++ b/tools/testing/selftests/bpf/progs/test_tc_edt.c
@@ -14,7 +14,6 @@
 #define TIME_HORIZON_NS (2000 * 1000 * 1000)
 #define NS_PER_SEC 1000000000
 #define ECN_HORIZON_NS 5000000
-#define THROTTLE_RATE_BPS (5 * 1000 * 1000)
 
 /* flow_key => last_tstamp timestamp used */
 struct {
@@ -24,12 +23,13 @@ struct {
        __uint(max_entries, 1);
 } flow_map SEC(".maps");
 
+__uint64_t target_rate;
+
 static inline int throttle_flow(struct __sk_buff *skb)
 {
        int key = 0;
        uint64_t *last_tstamp = bpf_map_lookup_elem(&flow_map, &key);
-       uint64_t delay_ns = ((uint64_t)skb->len) * NS_PER_SEC /
-                       THROTTLE_RATE_BPS;
+       uint64_t delay_ns = ((uint64_t)skb->len) * NS_PER_SEC / target_rate;
        uint64_t now = bpf_ktime_get_ns();
        uint64_t tstamp, next_tstamp = 0;