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 1bdb6c9a1c ("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
This commit is contained in:
Daniel T. Lee
2020-07-08 03:48:54 +09:00
committed by Daniel Borkmann
parent 88795b4adb
commit cc7f641d63
2 changed files with 189 additions and 140 deletions

View File

@@ -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;
}