Commit 9fd63d05 authored by Martin KaFai Lau's avatar Martin KaFai Lau Committed by David S. Miller
Browse files

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: default avatarMartin KaFai Lau <kafai@fb.com>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent bf8db5d2

samples/bpf/bpf_load.c

+96 −18
Original line number Diff line number Diff line
@@ -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)

{

	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)

{

	int fd, i;

	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)

samples/bpf/bpf_load.h

+13 −0
Original line number Diff line number Diff line
@@ -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 {

samples/bpf/map_perf_test_user.c

+92 −56
Original line number Diff line number Diff line
@@ -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;

	}

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