Commit 0d7ae068 authored by David Vernet's avatar David Vernet Committed by Daniel Borkmann
Browse files

selftests/bpf: 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.

Signed-off-by: default avatarDavid Vernet <void@manifault.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarSong Liu <song@kernel.org>
Acked-by: default avatarHou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/bpf/20231004162339.200702-3-void@manifault.com
parent d6247ecb

tools/testing/selftests/bpf/prog_tests/timer.c

+4 −0
Original line number Diff line number Diff line
@@ -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");

tools/testing/selftests/bpf/progs/timer.c

+62 −1
Original line number Diff line number Diff line
@@ -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;

}