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bpf: Allow bpf sample programs (*_user.c) to change bpf_map_def

The current bpf_map_def is statically defined during compile
time.  This patch allows the *_user.c program to change it during
runtime.  It is done by adding load_bpf_file_fixup_map() which
takes a callback.  The callback will be called before creating
each map so that it has a chance to modify the bpf_map_def.

The current usecase is to change max_entries in map_perf_test.
It is interesting to test with a much bigger map size in
some cases (e.g. the following patch on bpf_lru_map.c).
However,  it is hard to find one size to fit all testing
environment.  Hence, it is handy to take the max_entries
as a cmdline arg and then configure the bpf_map_def during
runtime.

This patch adds two cmdline args.  One is to configure
the map's max_entries.  Another is to configure the max_cnt
which controls how many times a syscall is called.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
zero-colors
Martin KaFai Lau 2017-04-14 10:30:28 -07:00 committed by David S. Miller
parent bf8db5d243
commit 9fd63d05f3
3 changed files with 201 additions and 74 deletions

View File

@ -21,6 +21,7 @@
#include <sys/mman.h>
#include <poll.h>
#include <ctype.h>
#include <assert.h>
#include "libbpf.h"
#include "bpf_load.h"
#include "perf-sys.h"
@ -37,15 +38,6 @@ int event_fd[MAX_PROGS];
int prog_cnt;
int prog_array_fd = -1;
struct bpf_map_def {
unsigned int type;
unsigned int key_size;
unsigned int value_size;
unsigned int max_entries;
unsigned int map_flags;
unsigned int inner_map_idx;
};
static int populate_prog_array(const char *event, int prog_fd)
{
int ind = atoi(event), err;
@ -193,11 +185,14 @@ static int load_and_attach(const char *event, struct bpf_insn *prog, int size)
return 0;
}
static int load_maps(struct bpf_map_def *maps, int len)
static int load_maps(struct bpf_map_def *maps, int len,
const char **map_names, fixup_map_cb fixup_map)
{
int i;
for (i = 0; i < len / sizeof(struct bpf_map_def); i++) {
if (fixup_map)
fixup_map(&maps[i], map_names[i], i);
if (maps[i].type == BPF_MAP_TYPE_ARRAY_OF_MAPS ||
maps[i].type == BPF_MAP_TYPE_HASH_OF_MAPS) {
@ -280,14 +275,64 @@ static int parse_relo_and_apply(Elf_Data *data, Elf_Data *symbols,
return 0;
}
int load_bpf_file(char *path)
static int cmp_symbols(const void *l, const void *r)
{
int fd, i;
const GElf_Sym *lsym = (const GElf_Sym *)l;
const GElf_Sym *rsym = (const GElf_Sym *)r;
if (lsym->st_value < rsym->st_value)
return -1;
else if (lsym->st_value > rsym->st_value)
return 1;
else
return 0;
}
static int get_sorted_map_names(Elf *elf, Elf_Data *symbols, int maps_shndx,
int strtabidx, char **map_names)
{
GElf_Sym map_symbols[MAX_MAPS];
int i, nr_maps = 0;
for (i = 0; i < symbols->d_size / sizeof(GElf_Sym); i++) {
assert(nr_maps < MAX_MAPS);
if (!gelf_getsym(symbols, i, &map_symbols[nr_maps]))
continue;
if (map_symbols[nr_maps].st_shndx != maps_shndx)
continue;
nr_maps++;
}
qsort(map_symbols, nr_maps, sizeof(GElf_Sym), cmp_symbols);
for (i = 0; i < nr_maps; i++) {
char *map_name;
map_name = elf_strptr(elf, strtabidx, map_symbols[i].st_name);
if (!map_name) {
printf("cannot get map symbol\n");
return 1;
}
map_names[i] = strdup(map_name);
if (!map_names[i]) {
printf("strdup(%s): %s(%d)\n", map_name,
strerror(errno), errno);
return 1;
}
}
return 0;
}
static int do_load_bpf_file(const char *path, fixup_map_cb fixup_map)
{
int fd, i, ret, maps_shndx = -1, strtabidx = -1;
Elf *elf;
GElf_Ehdr ehdr;
GElf_Shdr shdr, shdr_prog;
Elf_Data *data, *data_prog, *symbols = NULL;
char *shname, *shname_prog;
Elf_Data *data, *data_prog, *data_maps = NULL, *symbols = NULL;
char *shname, *shname_prog, *map_names[MAX_MAPS] = { NULL };
/* reset global variables */
kern_version = 0;
@ -335,14 +380,33 @@ int load_bpf_file(char *path)
}
memcpy(&kern_version, data->d_buf, sizeof(int));
} else if (strcmp(shname, "maps") == 0) {
processed_sec[i] = true;
if (load_maps(data->d_buf, data->d_size))
return 1;
maps_shndx = i;
data_maps = data;
} else if (shdr.sh_type == SHT_SYMTAB) {
strtabidx = shdr.sh_link;
symbols = data;
}
}
ret = 1;
if (!symbols) {
printf("missing SHT_SYMTAB section\n");
goto done;
}
if (data_maps) {
if (get_sorted_map_names(elf, symbols, maps_shndx, strtabidx,
map_names))
goto done;
if (load_maps(data_maps->d_buf, data_maps->d_size,
(const char **)map_names, fixup_map))
goto done;
processed_sec[maps_shndx] = true;
}
/* load programs that need map fixup (relocations) */
for (i = 1; i < ehdr.e_shnum; i++) {
if (processed_sec[i])
@ -399,8 +463,22 @@ int load_bpf_file(char *path)
load_and_attach(shname, data->d_buf, data->d_size);
}
ret = 0;
done:
for (i = 0; i < MAX_MAPS; i++)
free(map_names[i]);
close(fd);
return 0;
return ret;
}
int load_bpf_file(char *path)
{
return do_load_bpf_file(path, NULL);
}
int load_bpf_file_fixup_map(const char *path, fixup_map_cb fixup_map)
{
return do_load_bpf_file(path, fixup_map);
}
void read_trace_pipe(void)

View File

@ -6,6 +6,18 @@
#define MAX_MAPS 32
#define MAX_PROGS 32
struct bpf_map_def {
unsigned int type;
unsigned int key_size;
unsigned int value_size;
unsigned int max_entries;
unsigned int map_flags;
unsigned int inner_map_idx;
};
typedef void (*fixup_map_cb)(struct bpf_map_def *map, const char *map_name,
int idx);
extern int map_fd[MAX_MAPS];
extern int prog_fd[MAX_PROGS];
extern int event_fd[MAX_PROGS];
@ -25,6 +37,7 @@ extern int prog_cnt;
* returns zero on success
*/
int load_bpf_file(char *path);
int load_bpf_file_fixup_map(const char *path, fixup_map_cb fixup_map);
void read_trace_pipe(void);
struct ksym {

View File

@ -24,7 +24,7 @@
#include "libbpf.h"
#include "bpf_load.h"
#define MAX_CNT 1000000
#define TEST_BIT(t) (1U << (t))
static __u64 time_get_ns(void)
{
@ -34,17 +34,39 @@ static __u64 time_get_ns(void)
return ts.tv_sec * 1000000000ull + ts.tv_nsec;
}
#define HASH_PREALLOC (1 << 0)
#define PERCPU_HASH_PREALLOC (1 << 1)
#define HASH_KMALLOC (1 << 2)
#define PERCPU_HASH_KMALLOC (1 << 3)
#define LRU_HASH_PREALLOC (1 << 4)
#define NOCOMMON_LRU_HASH_PREALLOC (1 << 5)
#define LPM_KMALLOC (1 << 6)
#define HASH_LOOKUP (1 << 7)
#define ARRAY_LOOKUP (1 << 8)
enum test_type {
HASH_PREALLOC,
PERCPU_HASH_PREALLOC,
HASH_KMALLOC,
PERCPU_HASH_KMALLOC,
LRU_HASH_PREALLOC,
NOCOMMON_LRU_HASH_PREALLOC,
LPM_KMALLOC,
HASH_LOOKUP,
ARRAY_LOOKUP,
NR_TESTS,
};
const char *test_map_names[NR_TESTS] = {
[HASH_PREALLOC] = "hash_map",
[PERCPU_HASH_PREALLOC] = "percpu_hash_map",
[HASH_KMALLOC] = "hash_map_alloc",
[PERCPU_HASH_KMALLOC] = "percpu_hash_map_alloc",
[LRU_HASH_PREALLOC] = "lru_hash_map",
[NOCOMMON_LRU_HASH_PREALLOC] = "nocommon_lru_hash_map",
[LPM_KMALLOC] = "lpm_trie_map_alloc",
[HASH_LOOKUP] = "hash_map",
[ARRAY_LOOKUP] = "array_map",
};
static int test_flags = ~0;
static uint32_t num_map_entries;
static uint32_t max_cnt = 1000000;
static int check_test_flags(enum test_type t)
{
return test_flags & TEST_BIT(t);
}
static void test_hash_prealloc(int cpu)
{
@ -52,13 +74,13 @@ static void test_hash_prealloc(int cpu)
int i;
start_time = time_get_ns();
for (i = 0; i < MAX_CNT; i++)
for (i = 0; i < max_cnt; i++)
syscall(__NR_getuid);
printf("%d:hash_map_perf pre-alloc %lld events per sec\n",
cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
cpu, max_cnt * 1000000000ll / (time_get_ns() - start_time));
}
static void do_test_lru(int lru_test_flag, int cpu)
static void do_test_lru(enum test_type test, int cpu)
{
struct sockaddr_in6 in6 = { .sin6_family = AF_INET6 };
const char *test_name;
@ -68,10 +90,10 @@ static void do_test_lru(int lru_test_flag, int cpu)
in6.sin6_addr.s6_addr16[0] = 0xdead;
in6.sin6_addr.s6_addr16[1] = 0xbeef;
if (lru_test_flag & LRU_HASH_PREALLOC) {
if (test == LRU_HASH_PREALLOC) {
test_name = "lru_hash_map_perf";
in6.sin6_addr.s6_addr16[7] = 0;
} else if (lru_test_flag & NOCOMMON_LRU_HASH_PREALLOC) {
} else if (test == NOCOMMON_LRU_HASH_PREALLOC) {
test_name = "nocommon_lru_hash_map_perf";
in6.sin6_addr.s6_addr16[7] = 1;
} else {
@ -79,13 +101,13 @@ static void do_test_lru(int lru_test_flag, int cpu)
}
start_time = time_get_ns();
for (i = 0; i < MAX_CNT; i++) {
for (i = 0; i < max_cnt; i++) {
ret = connect(-1, (const struct sockaddr *)&in6, sizeof(in6));
assert(ret == -1 && errno == EBADF);
}
printf("%d:%s pre-alloc %lld events per sec\n",
cpu, test_name,
MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
max_cnt * 1000000000ll / (time_get_ns() - start_time));
}
static void test_lru_hash_prealloc(int cpu)
@ -104,10 +126,10 @@ static void test_percpu_hash_prealloc(int cpu)
int i;
start_time = time_get_ns();
for (i = 0; i < MAX_CNT; i++)
for (i = 0; i < max_cnt; i++)
syscall(__NR_geteuid);
printf("%d:percpu_hash_map_perf pre-alloc %lld events per sec\n",
cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
cpu, max_cnt * 1000000000ll / (time_get_ns() - start_time));
}
static void test_hash_kmalloc(int cpu)
@ -116,10 +138,10 @@ static void test_hash_kmalloc(int cpu)
int i;
start_time = time_get_ns();
for (i = 0; i < MAX_CNT; i++)
for (i = 0; i < max_cnt; i++)
syscall(__NR_getgid);
printf("%d:hash_map_perf kmalloc %lld events per sec\n",
cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
cpu, max_cnt * 1000000000ll / (time_get_ns() - start_time));
}
static void test_percpu_hash_kmalloc(int cpu)
@ -128,10 +150,10 @@ static void test_percpu_hash_kmalloc(int cpu)
int i;
start_time = time_get_ns();
for (i = 0; i < MAX_CNT; i++)
for (i = 0; i < max_cnt; i++)
syscall(__NR_getegid);
printf("%d:percpu_hash_map_perf kmalloc %lld events per sec\n",
cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
cpu, max_cnt * 1000000000ll / (time_get_ns() - start_time));
}
static void test_lpm_kmalloc(int cpu)
@ -140,10 +162,10 @@ static void test_lpm_kmalloc(int cpu)
int i;
start_time = time_get_ns();
for (i = 0; i < MAX_CNT; i++)
for (i = 0; i < max_cnt; i++)
syscall(__NR_gettid);
printf("%d:lpm_perf kmalloc %lld events per sec\n",
cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
cpu, max_cnt * 1000000000ll / (time_get_ns() - start_time));
}
static void test_hash_lookup(int cpu)
@ -152,10 +174,10 @@ static void test_hash_lookup(int cpu)
int i;
start_time = time_get_ns();
for (i = 0; i < MAX_CNT; i++)
for (i = 0; i < max_cnt; i++)
syscall(__NR_getpgid, 0);
printf("%d:hash_lookup %lld lookups per sec\n",
cpu, MAX_CNT * 1000000000ll * 64 / (time_get_ns() - start_time));
cpu, max_cnt * 1000000000ll * 64 / (time_get_ns() - start_time));
}
static void test_array_lookup(int cpu)
@ -164,46 +186,38 @@ static void test_array_lookup(int cpu)
int i;
start_time = time_get_ns();
for (i = 0; i < MAX_CNT; i++)
for (i = 0; i < max_cnt; i++)
syscall(__NR_getpgrp, 0);
printf("%d:array_lookup %lld lookups per sec\n",
cpu, MAX_CNT * 1000000000ll * 64 / (time_get_ns() - start_time));
cpu, max_cnt * 1000000000ll * 64 / (time_get_ns() - start_time));
}
typedef void (*test_func)(int cpu);
const test_func test_funcs[] = {
[HASH_PREALLOC] = test_hash_prealloc,
[PERCPU_HASH_PREALLOC] = test_percpu_hash_prealloc,
[HASH_KMALLOC] = test_hash_kmalloc,
[PERCPU_HASH_KMALLOC] = test_percpu_hash_kmalloc,
[LRU_HASH_PREALLOC] = test_lru_hash_prealloc,
[NOCOMMON_LRU_HASH_PREALLOC] = test_nocommon_lru_hash_prealloc,
[LPM_KMALLOC] = test_lpm_kmalloc,
[HASH_LOOKUP] = test_hash_lookup,
[ARRAY_LOOKUP] = test_array_lookup,
};
static void loop(int cpu)
{
cpu_set_t cpuset;
int i;
CPU_ZERO(&cpuset);
CPU_SET(cpu, &cpuset);
sched_setaffinity(0, sizeof(cpuset), &cpuset);
if (test_flags & HASH_PREALLOC)
test_hash_prealloc(cpu);
if (test_flags & PERCPU_HASH_PREALLOC)
test_percpu_hash_prealloc(cpu);
if (test_flags & HASH_KMALLOC)
test_hash_kmalloc(cpu);
if (test_flags & PERCPU_HASH_KMALLOC)
test_percpu_hash_kmalloc(cpu);
if (test_flags & LRU_HASH_PREALLOC)
test_lru_hash_prealloc(cpu);
if (test_flags & NOCOMMON_LRU_HASH_PREALLOC)
test_nocommon_lru_hash_prealloc(cpu);
if (test_flags & LPM_KMALLOC)
test_lpm_kmalloc(cpu);
if (test_flags & HASH_LOOKUP)
test_hash_lookup(cpu);
if (test_flags & ARRAY_LOOKUP)
test_array_lookup(cpu);
for (i = 0; i < NR_TESTS; i++) {
if (check_test_flags(i))
test_funcs[i](cpu);
}
}
static void run_perf_test(int tasks)
@ -260,6 +274,22 @@ static void fill_lpm_trie(void)
assert(!r);
}
static void fixup_map(struct bpf_map_def *map, const char *name, int idx)
{
int i;
if (num_map_entries <= 0)
return;
/* 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))) {
map->max_entries = num_map_entries;
}
}
}
int main(int argc, char **argv)
{
struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
@ -275,7 +305,13 @@ int main(int argc, char **argv)
if (argc > 2)
num_cpu = atoi(argv[2]) ? : num_cpu;
if (load_bpf_file(filename)) {
if (argc > 3)
num_map_entries = atoi(argv[3]);
if (argc > 4)
max_cnt = atoi(argv[4]);
if (load_bpf_file_fixup_map(filename, fixup_map)) {
printf("%s", bpf_log_buf);
return 1;
}