2023-10-04 16:24:32

by David Vernet

[permalink] [raw]
Subject: [PATCH bpf-next v2 2/2] bpf/selftests: Test pinning bpf timer to a core

Now that we support pinning a BPF timer to the current core, we should
test it with some selftests. This patch adds two new testcases to the
timer suite, which verifies that a BPF timer both with and without
BPF_F_TIMER_ABS, can be pinned to the calling core with
BPF_F_TIMER_CPU_PIN.

Acked-by: Song Liu <[email protected]>
Signed-off-by: David Vernet <[email protected]>
---
.../testing/selftests/bpf/prog_tests/timer.c | 4 ++
tools/testing/selftests/bpf/progs/timer.c | 63 ++++++++++++++++++-
2 files changed, 66 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/timer.c b/tools/testing/selftests/bpf/prog_tests/timer.c
index 290c21dbe65a..d8bc838445ec 100644
--- a/tools/testing/selftests/bpf/prog_tests/timer.c
+++ b/tools/testing/selftests/bpf/prog_tests/timer.c
@@ -14,6 +14,7 @@ static int timer(struct timer *timer_skel)

ASSERT_EQ(timer_skel->data->callback_check, 52, "callback_check1");
ASSERT_EQ(timer_skel->data->callback2_check, 52, "callback2_check1");
+ ASSERT_EQ(timer_skel->bss->pinned_callback_check, 0, "pinned_callback_check1");

prog_fd = bpf_program__fd(timer_skel->progs.test1);
err = bpf_prog_test_run_opts(prog_fd, &topts);
@@ -32,6 +33,9 @@ static int timer(struct timer *timer_skel)
/* check that timer_cb3() was executed twice */
ASSERT_EQ(timer_skel->bss->abs_data, 12, "abs_data");

+ /* check that timer_cb_pinned() was executed twice */
+ ASSERT_EQ(timer_skel->bss->pinned_callback_check, 2, "pinned_callback_check");
+
/* check that there were no errors in timer execution */
ASSERT_EQ(timer_skel->bss->err, 0, "err");

diff --git a/tools/testing/selftests/bpf/progs/timer.c b/tools/testing/selftests/bpf/progs/timer.c
index 9a16d95213e1..8b946c8188c6 100644
--- a/tools/testing/selftests/bpf/progs/timer.c
+++ b/tools/testing/selftests/bpf/progs/timer.c
@@ -51,7 +51,7 @@ struct {
__uint(max_entries, 1);
__type(key, int);
__type(value, struct elem);
-} abs_timer SEC(".maps");
+} abs_timer SEC(".maps"), soft_timer_pinned SEC(".maps"), abs_timer_pinned SEC(".maps");

__u64 bss_data;
__u64 abs_data;
@@ -59,6 +59,8 @@ __u64 err;
__u64 ok;
__u64 callback_check = 52;
__u64 callback2_check = 52;
+__u64 pinned_callback_check;
+__s32 pinned_cpu;

#define ARRAY 1
#define HTAB 2
@@ -329,3 +331,62 @@ int BPF_PROG2(test3, int, a)

return 0;
}
+
+/* callback for pinned timer */
+static int timer_cb_pinned(void *map, int *key, struct bpf_timer *timer)
+{
+ __s32 cpu = bpf_get_smp_processor_id();
+
+ if (cpu != pinned_cpu)
+ err |= 16384;
+
+ pinned_callback_check++;
+ return 0;
+}
+
+static void test_pinned_timer(bool soft)
+{
+ int key = 0;
+ void *map;
+ struct bpf_timer *timer;
+ __u64 flags = BPF_F_TIMER_CPU_PIN;
+ __u64 start_time;
+
+ if (soft) {
+ map = &soft_timer_pinned;
+ start_time = 0;
+ } else {
+ map = &abs_timer_pinned;
+ start_time = bpf_ktime_get_boot_ns();
+ flags |= BPF_F_TIMER_ABS;
+ }
+
+ timer = bpf_map_lookup_elem(map, &key);
+ if (timer) {
+ if (bpf_timer_init(timer, map, CLOCK_BOOTTIME) != 0)
+ err |= 4096;
+ bpf_timer_set_callback(timer, timer_cb_pinned);
+ pinned_cpu = bpf_get_smp_processor_id();
+ bpf_timer_start(timer, start_time + 1000, flags);
+ } else {
+ err |= 8192;
+ }
+}
+
+SEC("fentry/bpf_fentry_test4")
+int BPF_PROG2(test4, int, a)
+{
+ bpf_printk("test4");
+ test_pinned_timer(true);
+
+ return 0;
+}
+
+SEC("fentry/bpf_fentry_test5")
+int BPF_PROG2(test5, int, a)
+{
+ bpf_printk("test5");
+ test_pinned_timer(false);
+
+ return 0;
+}
--
2.41.0


2023-10-08 04:25:04

by Hou Tao

[permalink] [raw]
Subject: Re: [PATCH bpf-next v2 2/2] bpf/selftests: Test pinning bpf timer to a core



On 10/5/2023 12:23 AM, David Vernet wrote:
> Now that we support pinning a BPF timer to the current core, we should
> test it with some selftests. This patch adds two new testcases to the
> timer suite, which verifies that a BPF timer both with and without
> BPF_F_TIMER_ABS, can be pinned to the calling core with
> BPF_F_TIMER_CPU_PIN.
>
> Acked-by: Song Liu <[email protected]>
> Signed-off-by: David Vernet <[email protected]>

Acked-by: Hou Tao <[email protected]>