samples/bpf: unit test for BPF_MAP_TYPE_PERCPU_HASH
A sanity test for BPF_MAP_TYPE_PERCPU_HASH.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/samples/bpf/test_maps.c b/samples/bpf/test_maps.c
index 6299ee9..5f5fe53 100644
--- a/samples/bpf/test_maps.c
+++ b/samples/bpf/test_maps.c
@@ -89,6 +89,100 @@
close(map_fd);
}
+/* sanity tests for percpu map API */
+static void test_percpu_hashmap_sanity(int task, void *data)
+{
+ long long key, next_key;
+ int expected_key_mask = 0;
+ unsigned int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
+ long long value[nr_cpus];
+ int map_fd, i;
+
+ map_fd = bpf_create_map(BPF_MAP_TYPE_PERCPU_HASH, sizeof(key),
+ sizeof(value[0]), 2);
+ if (map_fd < 0) {
+ printf("failed to create hashmap '%s'\n", strerror(errno));
+ exit(1);
+ }
+
+ for (i = 0; i < nr_cpus; i++)
+ value[i] = i + 100;
+ key = 1;
+ /* insert key=1 element */
+ assert(!(expected_key_mask & key));
+ assert(bpf_update_elem(map_fd, &key, value, BPF_ANY) == 0);
+ expected_key_mask |= key;
+
+ /* BPF_NOEXIST means: add new element if it doesn't exist */
+ assert(bpf_update_elem(map_fd, &key, value, BPF_NOEXIST) == -1 &&
+ /* key=1 already exists */
+ errno == EEXIST);
+
+ /* -1 is an invalid flag */
+ assert(bpf_update_elem(map_fd, &key, value, -1) == -1 &&
+ errno == EINVAL);
+
+ /* check that key=1 can be found. value could be 0 if the lookup
+ * was run from a different cpu.
+ */
+ value[0] = 1;
+ assert(bpf_lookup_elem(map_fd, &key, value) == 0 && value[0] == 100);
+
+ key = 2;
+ /* check that key=2 is not found */
+ assert(bpf_lookup_elem(map_fd, &key, value) == -1 && errno == ENOENT);
+
+ /* BPF_EXIST means: update existing element */
+ assert(bpf_update_elem(map_fd, &key, value, BPF_EXIST) == -1 &&
+ /* key=2 is not there */
+ errno == ENOENT);
+
+ /* insert key=2 element */
+ assert(!(expected_key_mask & key));
+ assert(bpf_update_elem(map_fd, &key, value, BPF_NOEXIST) == 0);
+ expected_key_mask |= key;
+
+ /* key=1 and key=2 were inserted, check that key=0 cannot be inserted
+ * due to max_entries limit
+ */
+ key = 0;
+ assert(bpf_update_elem(map_fd, &key, value, BPF_NOEXIST) == -1 &&
+ errno == E2BIG);
+
+ /* check that key = 0 doesn't exist */
+ assert(bpf_delete_elem(map_fd, &key) == -1 && errno == ENOENT);
+
+ /* iterate over two elements */
+ while (!bpf_get_next_key(map_fd, &key, &next_key)) {
+ assert((expected_key_mask & next_key) == next_key);
+ expected_key_mask &= ~next_key;
+
+ assert(bpf_lookup_elem(map_fd, &next_key, value) == 0);
+ for (i = 0; i < nr_cpus; i++)
+ assert(value[i] == i + 100);
+
+ key = next_key;
+ }
+ assert(errno == ENOENT);
+
+ /* Update with BPF_EXIST */
+ key = 1;
+ assert(bpf_update_elem(map_fd, &key, value, BPF_EXIST) == 0);
+
+ /* delete both elements */
+ key = 1;
+ assert(bpf_delete_elem(map_fd, &key) == 0);
+ key = 2;
+ assert(bpf_delete_elem(map_fd, &key) == 0);
+ assert(bpf_delete_elem(map_fd, &key) == -1 && errno == ENOENT);
+
+ key = 0;
+ /* check that map is empty */
+ assert(bpf_get_next_key(map_fd, &key, &next_key) == -1 &&
+ errno == ENOENT);
+ close(map_fd);
+}
+
static void test_arraymap_sanity(int i, void *data)
{
int key, next_key, map_fd;
@@ -209,6 +303,7 @@
static void test_map_stress(void)
{
run_parallel(100, test_hashmap_sanity, NULL);
+ run_parallel(100, test_percpu_hashmap_sanity, NULL);
run_parallel(100, test_arraymap_sanity, NULL);
}
@@ -282,6 +377,7 @@
int main(void)
{
test_hashmap_sanity(0, NULL);
+ test_percpu_hashmap_sanity(0, NULL);
test_arraymap_sanity(0, NULL);
test_map_large();
test_map_parallel();