samples: bpf: Refactor BPF map performance test with libbpf
Previously, in order to set the numa_node attribute at the time of map
creation using "libbpf", it was necessary to call bpf_create_map_node()
directly (bpf_load approach), instead of calling bpf_object_load()
that handles everything on its own, including map creation. And because
of this problem, this sample had problems with refactoring from bpf_load
to libbbpf.
However, by commit 1bdb6c9a1c43 ("libbpf: Add a bunch of attribute
getters/setters for map definitions") added the numa_node attribute and
allowed it to be set in the map.
By using libbpf instead of bpf_load, the inner map definition has
been explicitly declared with BTF-defined format. Also, the element of
ARRAY_OF_MAPS was also statically specified using the BTF format. And
for this reason some logic in fixup_map() was not needed and changed
or removed.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200707184855.30968-4-danieltimlee@gmail.com
diff --git a/samples/bpf/map_perf_test_user.c b/samples/bpf/map_perf_test_user.c
index fe5564b..8b13230 100644
--- a/samples/bpf/map_perf_test_user.c
+++ b/samples/bpf/map_perf_test_user.c
@@ -11,7 +11,6 @@
#include <sys/wait.h>
#include <stdlib.h>
#include <signal.h>
-#include <linux/bpf.h>
#include <string.h>
#include <time.h>
#include <sys/resource.h>
@@ -19,7 +18,7 @@
#include <errno.h>
#include <bpf/bpf.h>
-#include "bpf_load.h"
+#include <bpf/libbpf.h>
#define TEST_BIT(t) (1U << (t))
#define MAX_NR_CPUS 1024
@@ -61,12 +60,18 @@ const char *test_map_names[NR_TESTS] = {
[LRU_HASH_LOOKUP] = "lru_hash_lookup_map",
};
+enum map_idx {
+ array_of_lru_hashs_idx,
+ hash_map_alloc_idx,
+ lru_hash_lookup_idx,
+ NR_IDXES,
+};
+
+static int map_fd[NR_IDXES];
+
static int test_flags = ~0;
static uint32_t num_map_entries;
static uint32_t inner_lru_hash_size;
-static int inner_lru_hash_idx = -1;
-static int array_of_lru_hashs_idx = -1;
-static int lru_hash_lookup_idx = -1;
static int lru_hash_lookup_test_entries = 32;
static uint32_t max_cnt = 1000000;
@@ -122,30 +127,30 @@ static void do_test_lru(enum test_type test, int cpu)
__u64 start_time;
int i, ret;
- if (test == INNER_LRU_HASH_PREALLOC) {
+ if (test == INNER_LRU_HASH_PREALLOC && cpu) {
+ /* If CPU is not 0, create inner_lru hash map and insert the fd
+ * value into the array_of_lru_hash map. In case of CPU 0,
+ * 'inner_lru_hash_map' was statically inserted on the map init
+ */
int outer_fd = map_fd[array_of_lru_hashs_idx];
unsigned int mycpu, mynode;
assert(cpu < MAX_NR_CPUS);
- if (cpu) {
- ret = syscall(__NR_getcpu, &mycpu, &mynode, NULL);
- assert(!ret);
+ ret = syscall(__NR_getcpu, &mycpu, &mynode, NULL);
+ assert(!ret);
- inner_lru_map_fds[cpu] =
- bpf_create_map_node(BPF_MAP_TYPE_LRU_HASH,
- test_map_names[INNER_LRU_HASH_PREALLOC],
- sizeof(uint32_t),
- sizeof(long),
- inner_lru_hash_size, 0,
- mynode);
- if (inner_lru_map_fds[cpu] == -1) {
- printf("cannot create BPF_MAP_TYPE_LRU_HASH %s(%d)\n",
- strerror(errno), errno);
- exit(1);
- }
- } else {
- inner_lru_map_fds[cpu] = map_fd[inner_lru_hash_idx];
+ inner_lru_map_fds[cpu] =
+ bpf_create_map_node(BPF_MAP_TYPE_LRU_HASH,
+ test_map_names[INNER_LRU_HASH_PREALLOC],
+ sizeof(uint32_t),
+ sizeof(long),
+ inner_lru_hash_size, 0,
+ mynode);
+ if (inner_lru_map_fds[cpu] == -1) {
+ printf("cannot create BPF_MAP_TYPE_LRU_HASH %s(%d)\n",
+ strerror(errno), errno);
+ exit(1);
}
ret = bpf_map_update_elem(outer_fd, &cpu,
@@ -377,7 +382,8 @@ static void fill_lpm_trie(void)
key->data[1] = rand() & 0xff;
key->data[2] = rand() & 0xff;
key->data[3] = rand() & 0xff;
- r = bpf_map_update_elem(map_fd[6], key, &value, 0);
+ r = bpf_map_update_elem(map_fd[hash_map_alloc_idx],
+ key, &value, 0);
assert(!r);
}
@@ -388,59 +394,52 @@ static void fill_lpm_trie(void)
key->data[3] = 1;
value = 128;
- r = bpf_map_update_elem(map_fd[6], key, &value, 0);
+ r = bpf_map_update_elem(map_fd[hash_map_alloc_idx], key, &value, 0);
assert(!r);
}
-static void fixup_map(struct bpf_map_data *map, int idx)
+static void fixup_map(struct bpf_object *obj)
{
+ struct bpf_map *map;
int i;
- if (!strcmp("inner_lru_hash_map", map->name)) {
- inner_lru_hash_idx = idx;
- inner_lru_hash_size = map->def.max_entries;
- }
+ bpf_object__for_each_map(map, obj) {
+ const char *name = bpf_map__name(map);
- if (!strcmp("array_of_lru_hashs", map->name)) {
- if (inner_lru_hash_idx == -1) {
- printf("inner_lru_hash_map must be defined before array_of_lru_hashs\n");
- exit(1);
+ /* Only change the max_entries for the enabled test(s) */
+ for (i = 0; i < NR_TESTS; i++) {
+ if (!strcmp(test_map_names[i], name) &&
+ (check_test_flags(i))) {
+ bpf_map__resize(map, num_map_entries);
+ continue;
+ }
}
- map->def.inner_map_idx = inner_lru_hash_idx;
- array_of_lru_hashs_idx = idx;
}
- if (!strcmp("lru_hash_lookup_map", map->name))
- lru_hash_lookup_idx = idx;
-
- if (num_map_entries <= 0)
- return;
-
inner_lru_hash_size = num_map_entries;
-
- /* Only change the max_entries for the enabled test(s) */
- for (i = 0; i < NR_TESTS; i++) {
- if (!strcmp(test_map_names[i], map->name) &&
- (check_test_flags(i))) {
- map->def.max_entries = num_map_entries;
- }
- }
}
int main(int argc, char **argv)
{
struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+ int nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
+ struct bpf_link *links[8];
+ struct bpf_program *prog;
+ struct bpf_object *obj;
+ struct bpf_map *map;
char filename[256];
- int num_cpu = 8;
+ int i = 0;
- snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
- setrlimit(RLIMIT_MEMLOCK, &r);
+ if (setrlimit(RLIMIT_MEMLOCK, &r)) {
+ perror("setrlimit(RLIMIT_MEMLOCK)");
+ return 1;
+ }
if (argc > 1)
test_flags = atoi(argv[1]) ? : test_flags;
if (argc > 2)
- num_cpu = atoi(argv[2]) ? : num_cpu;
+ nr_cpus = atoi(argv[2]) ? : nr_cpus;
if (argc > 3)
num_map_entries = atoi(argv[3]);
@@ -448,14 +447,61 @@ int main(int argc, char **argv)
if (argc > 4)
max_cnt = atoi(argv[4]);
- if (load_bpf_file_fixup_map(filename, fixup_map)) {
- printf("%s", bpf_log_buf);
- return 1;
+ snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+ obj = bpf_object__open_file(filename, NULL);
+ if (libbpf_get_error(obj)) {
+ fprintf(stderr, "ERROR: opening BPF object file failed\n");
+ return 0;
+ }
+
+ map = bpf_object__find_map_by_name(obj, "inner_lru_hash_map");
+ if (libbpf_get_error(map)) {
+ fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+ goto cleanup;
+ }
+
+ inner_lru_hash_size = bpf_map__max_entries(map);
+ if (!inner_lru_hash_size) {
+ fprintf(stderr, "ERROR: failed to get map attribute\n");
+ goto cleanup;
+ }
+
+ /* resize BPF map prior to loading */
+ if (num_map_entries > 0)
+ fixup_map(obj);
+
+ /* load BPF program */
+ if (bpf_object__load(obj)) {
+ fprintf(stderr, "ERROR: loading BPF object file failed\n");
+ goto cleanup;
+ }
+
+ map_fd[0] = bpf_object__find_map_fd_by_name(obj, "array_of_lru_hashs");
+ map_fd[1] = bpf_object__find_map_fd_by_name(obj, "hash_map_alloc");
+ map_fd[2] = bpf_object__find_map_fd_by_name(obj, "lru_hash_lookup_map");
+ if (map_fd[0] < 0 || map_fd[1] < 0 || map_fd[2] < 0) {
+ fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+ goto cleanup;
+ }
+
+ bpf_object__for_each_program(prog, obj) {
+ links[i] = bpf_program__attach(prog);
+ if (libbpf_get_error(links[i])) {
+ fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+ links[i] = NULL;
+ goto cleanup;
+ }
+ i++;
}
fill_lpm_trie();
- run_perf_test(num_cpu);
+ run_perf_test(nr_cpus);
+cleanup:
+ for (i--; i >= 0; i--)
+ bpf_link__destroy(links[i]);
+
+ bpf_object__close(obj);
return 0;
}