samples: bpf: Refactor BPF map performance test with libbpf
authorDaniel T. Lee <danieltimlee@gmail.com>
Tue, 7 Jul 2020 18:48:54 +0000 (03:48 +0900)
committerDaniel Borkmann <daniel@iogearbox.net>
Tue, 7 Jul 2020 23:33:14 +0000 (01:33 +0200)
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
samples/bpf/map_perf_test_kern.c
samples/bpf/map_perf_test_user.c

index c9b31193ca12809504f48aa615ece37557003192..8773f22b6a983cd51c1625270c3f930d6ac6d34b 100644 (file)
@@ -9,7 +9,6 @@
 #include <linux/version.h>
 #include <uapi/linux/bpf.h>
 #include <bpf/bpf_helpers.h>
-#include "bpf_legacy.h"
 #include <bpf/bpf_tracing.h>
 #include <bpf/bpf_core_read.h>
 #include "trace_common.h"
 #define MAX_ENTRIES 1000
 #define MAX_NR_CPUS 1024
 
-struct bpf_map_def_legacy SEC("maps") hash_map = {
-       .type = BPF_MAP_TYPE_HASH,
-       .key_size = sizeof(u32),
-       .value_size = sizeof(long),
-       .max_entries = MAX_ENTRIES,
+struct {
+       __uint(type, BPF_MAP_TYPE_HASH);
+       __type(key, u32);
+       __type(value, long);
+       __uint(max_entries, MAX_ENTRIES);
+} hash_map SEC(".maps");
+
+struct {
+       __uint(type, BPF_MAP_TYPE_LRU_HASH);
+       __type(key, u32);
+       __type(value, long);
+       __uint(max_entries, 10000);
+} lru_hash_map SEC(".maps");
+
+struct {
+       __uint(type, BPF_MAP_TYPE_LRU_HASH);
+       __type(key, u32);
+       __type(value, long);
+       __uint(max_entries, 10000);
+       __uint(map_flags, BPF_F_NO_COMMON_LRU);
+} nocommon_lru_hash_map SEC(".maps");
+
+struct inner_lru {
+       __uint(type, BPF_MAP_TYPE_LRU_HASH);
+       __type(key, u32);
+       __type(value, long);
+       __uint(max_entries, MAX_ENTRIES);
+       __uint(map_flags, BPF_F_NUMA_NODE);
+       __uint(numa_node, 0);
+} inner_lru_hash_map SEC(".maps");
+
+struct {
+       __uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
+       __uint(max_entries, MAX_NR_CPUS);
+       __uint(key_size, sizeof(u32));
+       __array(values, struct inner_lru); /* use inner_lru as inner map */
+} array_of_lru_hashs SEC(".maps") = {
+       /* statically initialize the first element */
+       .values = { &inner_lru_hash_map },
 };
 
-struct bpf_map_def_legacy SEC("maps") lru_hash_map = {
-       .type = BPF_MAP_TYPE_LRU_HASH,
-       .key_size = sizeof(u32),
-       .value_size = sizeof(long),
-       .max_entries = 10000,
-};
-
-struct bpf_map_def_legacy SEC("maps") nocommon_lru_hash_map = {
-       .type = BPF_MAP_TYPE_LRU_HASH,
-       .key_size = sizeof(u32),
-       .value_size = sizeof(long),
-       .max_entries = 10000,
-       .map_flags = BPF_F_NO_COMMON_LRU,
-};
-
-struct bpf_map_def_legacy SEC("maps") inner_lru_hash_map = {
-       .type = BPF_MAP_TYPE_LRU_HASH,
-       .key_size = sizeof(u32),
-       .value_size = sizeof(long),
-       .max_entries = MAX_ENTRIES,
-       .map_flags = BPF_F_NUMA_NODE,
-       .numa_node = 0,
-};
-
-struct bpf_map_def_legacy SEC("maps") array_of_lru_hashs = {
-       .type = BPF_MAP_TYPE_ARRAY_OF_MAPS,
-       .key_size = sizeof(u32),
-       .max_entries = MAX_NR_CPUS,
-};
-
-struct bpf_map_def_legacy SEC("maps") percpu_hash_map = {
-       .type = BPF_MAP_TYPE_PERCPU_HASH,
-       .key_size = sizeof(u32),
-       .value_size = sizeof(long),
-       .max_entries = MAX_ENTRIES,
-};
-
-struct bpf_map_def_legacy SEC("maps") hash_map_alloc = {
-       .type = BPF_MAP_TYPE_HASH,
-       .key_size = sizeof(u32),
-       .value_size = sizeof(long),
-       .max_entries = MAX_ENTRIES,
-       .map_flags = BPF_F_NO_PREALLOC,
-};
-
-struct bpf_map_def_legacy SEC("maps") percpu_hash_map_alloc = {
-       .type = BPF_MAP_TYPE_PERCPU_HASH,
-       .key_size = sizeof(u32),
-       .value_size = sizeof(long),
-       .max_entries = MAX_ENTRIES,
-       .map_flags = BPF_F_NO_PREALLOC,
-};
-
-struct bpf_map_def_legacy SEC("maps") lpm_trie_map_alloc = {
-       .type = BPF_MAP_TYPE_LPM_TRIE,
-       .key_size = 8,
-       .value_size = sizeof(long),
-       .max_entries = 10000,
-       .map_flags = BPF_F_NO_PREALLOC,
-};
-
-struct bpf_map_def_legacy SEC("maps") array_map = {
-       .type = BPF_MAP_TYPE_ARRAY,
-       .key_size = sizeof(u32),
-       .value_size = sizeof(long),
-       .max_entries = MAX_ENTRIES,
-};
-
-struct bpf_map_def_legacy SEC("maps") lru_hash_lookup_map = {
-       .type = BPF_MAP_TYPE_LRU_HASH,
-       .key_size = sizeof(u32),
-       .value_size = sizeof(long),
-       .max_entries = MAX_ENTRIES,
-};
-
-SEC("kprobe/sys_getuid")
+struct {
+       __uint(type, BPF_MAP_TYPE_PERCPU_HASH);
+       __uint(key_size, sizeof(u32));
+       __uint(value_size, sizeof(long));
+       __uint(max_entries, MAX_ENTRIES);
+} percpu_hash_map SEC(".maps");
+
+struct {
+       __uint(type, BPF_MAP_TYPE_HASH);
+       __type(key, u32);
+       __type(value, long);
+       __uint(max_entries, MAX_ENTRIES);
+       __uint(map_flags, BPF_F_NO_PREALLOC);
+} hash_map_alloc SEC(".maps");
+
+struct {
+       __uint(type, BPF_MAP_TYPE_PERCPU_HASH);
+       __uint(key_size, sizeof(u32));
+       __uint(value_size, sizeof(long));
+       __uint(max_entries, MAX_ENTRIES);
+       __uint(map_flags, BPF_F_NO_PREALLOC);
+} percpu_hash_map_alloc SEC(".maps");
+
+struct {
+       __uint(type, BPF_MAP_TYPE_LPM_TRIE);
+       __uint(key_size, 8);
+       __uint(value_size, sizeof(long));
+       __uint(max_entries, 10000);
+       __uint(map_flags, BPF_F_NO_PREALLOC);
+} lpm_trie_map_alloc SEC(".maps");
+
+struct {
+       __uint(type, BPF_MAP_TYPE_ARRAY);
+       __type(key, u32);
+       __type(value, long);
+       __uint(max_entries, MAX_ENTRIES);
+} array_map SEC(".maps");
+
+struct {
+       __uint(type, BPF_MAP_TYPE_LRU_HASH);
+       __type(key, u32);
+       __type(value, long);
+       __uint(max_entries, MAX_ENTRIES);
+} lru_hash_lookup_map SEC(".maps");
+
+SEC("kprobe/" SYSCALL(sys_getuid))
 int stress_hmap(struct pt_regs *ctx)
 {
        u32 key = bpf_get_current_pid_tgid();
@@ -114,7 +117,7 @@ int stress_hmap(struct pt_regs *ctx)
        return 0;
 }
 
-SEC("kprobe/sys_geteuid")
+SEC("kprobe/" SYSCALL(sys_geteuid))
 int stress_percpu_hmap(struct pt_regs *ctx)
 {
        u32 key = bpf_get_current_pid_tgid();
@@ -128,7 +131,7 @@ int stress_percpu_hmap(struct pt_regs *ctx)
        return 0;
 }
 
-SEC("kprobe/sys_getgid")
+SEC("kprobe/" SYSCALL(sys_getgid))
 int stress_hmap_alloc(struct pt_regs *ctx)
 {
        u32 key = bpf_get_current_pid_tgid();
@@ -142,7 +145,7 @@ int stress_hmap_alloc(struct pt_regs *ctx)
        return 0;
 }
 
-SEC("kprobe/sys_getegid")
+SEC("kprobe/" SYSCALL(sys_getegid))
 int stress_percpu_hmap_alloc(struct pt_regs *ctx)
 {
        u32 key = bpf_get_current_pid_tgid();
@@ -236,7 +239,7 @@ done:
        return 0;
 }
 
-SEC("kprobe/sys_gettid")
+SEC("kprobe/" SYSCALL(sys_gettid))
 int stress_lpm_trie_map_alloc(struct pt_regs *ctx)
 {
        union {
@@ -258,7 +261,7 @@ int stress_lpm_trie_map_alloc(struct pt_regs *ctx)
        return 0;
 }
 
-SEC("kprobe/sys_getpgid")
+SEC("kprobe/" SYSCALL(sys_getpgid))
 int stress_hash_map_lookup(struct pt_regs *ctx)
 {
        u32 key = 1, i;
@@ -271,7 +274,7 @@ int stress_hash_map_lookup(struct pt_regs *ctx)
        return 0;
 }
 
-SEC("kprobe/sys_getppid")
+SEC("kprobe/" SYSCALL(sys_getppid))
 int stress_array_map_lookup(struct pt_regs *ctx)
 {
        u32 key = 1, i;
index fe5564bff39b9004f0143ba5b59558180f830756..8b13230b4c468f1e4f26d87899f8081acf980158 100644 (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);
-
-                       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];
+               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);
                }
 
                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;
 }