Messages in this thread Patch in this message | | | From | Martin KaFai Lau <> | Subject | [PATCH v2 net-next 4/4] bpf: bpf_htab: Test for BPF_MAP_TYPE_PERCPU_HASH | Date | Tue, 12 Jan 2016 00:20:52 -0800 |
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A sanity test for BPF_MAP_TYPE_PERCPU_HASH.
Signed-off-by: Martin KaFai Lau <kafai@fb.com> --- samples/bpf/libbpf.c | 13 ++++++ samples/bpf/libbpf.h | 1 + samples/bpf/test_maps.c | 113 ++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 127 insertions(+)
diff --git a/samples/bpf/libbpf.c b/samples/bpf/libbpf.c index 65a8d48..a9c5e61 100644 --- a/samples/bpf/libbpf.c +++ b/samples/bpf/libbpf.c @@ -54,6 +54,19 @@ int bpf_lookup_elem(int fd, void *key, void *value) return syscall(__NR_bpf, BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr)); } +int bpf_lookup_percpu_elem(int fd, void *key, void *value, unsigned int cpu) +{ + union bpf_attr attr = { + .map_fd = fd, + .key = ptr_to_u64(key), + .value = ptr_to_u64(value), + .cpu = cpu, + }; + + return syscall(__NR_bpf, BPF_MAP_LOOKUP_PERCPU_ELEM, &attr, + sizeof(attr)); +} + int bpf_delete_elem(int fd, void *key) { union bpf_attr attr = { diff --git a/samples/bpf/libbpf.h b/samples/bpf/libbpf.h index 014aacf..7759517 100644 --- a/samples/bpf/libbpf.h +++ b/samples/bpf/libbpf.h @@ -8,6 +8,7 @@ int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size, int max_entries); int bpf_update_elem(int fd, void *key, void *value, unsigned long long flags); int bpf_lookup_elem(int fd, void *key, void *value); +int bpf_lookup_percpu_elem(int fd, void *key, void *value, unsigned int cpu); int bpf_delete_elem(int fd, void *key); int bpf_get_next_key(int fd, void *key, void *next_key); diff --git a/samples/bpf/test_maps.c b/samples/bpf/test_maps.c index 6299ee9..7b1dc3e 100644 --- a/samples/bpf/test_maps.c +++ b/samples/bpf/test_maps.c @@ -89,6 +89,118 @@ static void test_hashmap_sanity(int i, void *data) close(map_fd); } +/* sanity tests for percpu map API */ +static void test_percpu_hashmap_sanity(int i, void *data) +{ + long long key, next_key, value; + int expected_key_mask = 0; + unsigned int nr_cpus = sysconf(_SC_NPROCESSORS_CONF); + int map_fd; + + map_fd = bpf_create_map(BPF_MAP_TYPE_PERCPU_HASH, sizeof(key), + sizeof(value), 2); + if (map_fd < 0) { + printf("failed to create hashmap '%s'\n", strerror(errno)); + exit(1); + } + + key = 1; + value = 1234; + /* 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. + */ + assert(bpf_lookup_elem(map_fd, &key, &value) == 0 && + (value == 0 || value == 1234)); + + 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)) { + unsigned int cpu; + int found; + + assert((expected_key_mask & next_key) == next_key); + expected_key_mask &= ~next_key; + + found = 0; + for (cpu = 0; cpu < nr_cpus; cpu++) { + if (!bpf_lookup_percpu_elem(map_fd, &next_key, + &value, cpu)) { + if (value == 1234) { + assert(!found); + found = 1; + } else { + assert(value == 0); + } + } else { + assert(errno == ENXIO); + } + } + assert(found); + + key = next_key; + } + assert(errno == ENOENT); + + /* Look up the value with an invalid CPU */ + key = 1; + assert(bpf_lookup_percpu_elem(map_fd, &key, &value, nr_cpus) == -1 && + errno == EINVAL); + + /* 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; @@ -282,6 +394,7 @@ static void test_map_parallel(void) 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(); -- 2.5.1
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