Joanne Koong f6e659b7f9 selftests/bpf: Measure bpf_loop verifier performance
This patch tests bpf_loop in pyperf and strobemeta, and measures the
verifier performance of replacing the traditional for loop
with bpf_loop.

The results are as follows:

~strobemeta~

Baseline
    verification time 6808200 usec
    stack depth 496
    processed 554252 insns (limit 1000000) max_states_per_insn 16
    total_states 15878 peak_states 13489  mark_read 3110
    #192 verif_scale_strobemeta:OK (unrolled loop)

Using bpf_loop
    verification time 31589 usec
    stack depth 96+400
    processed 1513 insns (limit 1000000) max_states_per_insn 2
    total_states 106 peak_states 106 mark_read 60
    #193 verif_scale_strobemeta_bpf_loop:OK

~pyperf600~

Baseline
    verification time 29702486 usec
    stack depth 368
    processed 626838 insns (limit 1000000) max_states_per_insn 7
    total_states 30368 peak_states 30279 mark_read 748
    #182 verif_scale_pyperf600:OK (unrolled loop)

Using bpf_loop
    verification time 148488 usec
    stack depth 320+40
    processed 10518 insns (limit 1000000) max_states_per_insn 10
    total_states 705 peak_states 517 mark_read 38
    #183 verif_scale_pyperf600_bpf_loop:OK

Using the bpf_loop helper led to approximately a 99% decrease
in the verification time and in the number of instructions.

Signed-off-by: Joanne Koong <joannekoong@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211130030622.4131246-4-joannekoong@fb.com
2021-11-30 10:56:28 -08:00

222 lines
4.8 KiB
C

// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2019 Facebook
#include <test_progs.h>
static int libbpf_debug_print(enum libbpf_print_level level,
const char *format, va_list args)
{
if (level != LIBBPF_DEBUG) {
vprintf(format, args);
return 0;
}
if (!strstr(format, "verifier log"))
return 0;
vprintf("%s", args);
return 0;
}
extern int extra_prog_load_log_flags;
static int check_load(const char *file, enum bpf_prog_type type)
{
struct bpf_prog_load_attr attr;
struct bpf_object *obj = NULL;
int err, prog_fd;
memset(&attr, 0, sizeof(struct bpf_prog_load_attr));
attr.file = file;
attr.prog_type = type;
attr.log_level = 4 | extra_prog_load_log_flags;
attr.prog_flags = BPF_F_TEST_RND_HI32;
err = bpf_prog_load_xattr(&attr, &obj, &prog_fd);
bpf_object__close(obj);
return err;
}
struct scale_test_def {
const char *file;
enum bpf_prog_type attach_type;
bool fails;
};
static void scale_test(const char *file,
enum bpf_prog_type attach_type,
bool should_fail)
{
libbpf_print_fn_t old_print_fn = NULL;
int err;
if (env.verifier_stats) {
test__force_log();
old_print_fn = libbpf_set_print(libbpf_debug_print);
}
err = check_load(file, attach_type);
if (should_fail)
ASSERT_ERR(err, "expect_error");
else
ASSERT_OK(err, "expect_success");
if (env.verifier_stats)
libbpf_set_print(old_print_fn);
}
void test_verif_scale1()
{
scale_test("test_verif_scale1.o", BPF_PROG_TYPE_SCHED_CLS, false);
}
void test_verif_scale2()
{
scale_test("test_verif_scale2.o", BPF_PROG_TYPE_SCHED_CLS, false);
}
void test_verif_scale3()
{
scale_test("test_verif_scale3.o", BPF_PROG_TYPE_SCHED_CLS, false);
}
void test_verif_scale_pyperf_global()
{
scale_test("pyperf_global.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
}
void test_verif_scale_pyperf_subprogs()
{
scale_test("pyperf_subprogs.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
}
void test_verif_scale_pyperf50()
{
/* full unroll by llvm */
scale_test("pyperf50.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
}
void test_verif_scale_pyperf100()
{
/* full unroll by llvm */
scale_test("pyperf100.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
}
void test_verif_scale_pyperf180()
{
/* full unroll by llvm */
scale_test("pyperf180.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
}
void test_verif_scale_pyperf600()
{
/* partial unroll. llvm will unroll loop ~150 times.
* C loop count -> 600.
* Asm loop count -> 4.
* 16k insns in loop body.
* Total of 5 such loops. Total program size ~82k insns.
*/
scale_test("pyperf600.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
}
void test_verif_scale_pyperf600_bpf_loop(void)
{
/* use the bpf_loop helper*/
scale_test("pyperf600_bpf_loop.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
}
void test_verif_scale_pyperf600_nounroll()
{
/* no unroll at all.
* C loop count -> 600.
* ASM loop count -> 600.
* ~110 insns in loop body.
* Total of 5 such loops. Total program size ~1500 insns.
*/
scale_test("pyperf600_nounroll.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
}
void test_verif_scale_loop1()
{
scale_test("loop1.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
}
void test_verif_scale_loop2()
{
scale_test("loop2.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
}
void test_verif_scale_loop3_fail()
{
scale_test("loop3.o", BPF_PROG_TYPE_RAW_TRACEPOINT, true /* fails */);
}
void test_verif_scale_loop4()
{
scale_test("loop4.o", BPF_PROG_TYPE_SCHED_CLS, false);
}
void test_verif_scale_loop5()
{
scale_test("loop5.o", BPF_PROG_TYPE_SCHED_CLS, false);
}
void test_verif_scale_loop6()
{
scale_test("loop6.o", BPF_PROG_TYPE_KPROBE, false);
}
void test_verif_scale_strobemeta()
{
/* partial unroll. 19k insn in a loop.
* Total program size 20.8k insn.
* ~350k processed_insns
*/
scale_test("strobemeta.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
}
void test_verif_scale_strobemeta_bpf_loop(void)
{
/* use the bpf_loop helper*/
scale_test("strobemeta_bpf_loop.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
}
void test_verif_scale_strobemeta_nounroll1()
{
/* no unroll, tiny loops */
scale_test("strobemeta_nounroll1.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
}
void test_verif_scale_strobemeta_nounroll2()
{
/* no unroll, tiny loops */
scale_test("strobemeta_nounroll2.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
}
void test_verif_scale_strobemeta_subprogs()
{
/* non-inlined subprogs */
scale_test("strobemeta_subprogs.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false);
}
void test_verif_scale_sysctl_loop1()
{
scale_test("test_sysctl_loop1.o", BPF_PROG_TYPE_CGROUP_SYSCTL, false);
}
void test_verif_scale_sysctl_loop2()
{
scale_test("test_sysctl_loop2.o", BPF_PROG_TYPE_CGROUP_SYSCTL, false);
}
void test_verif_scale_xdp_loop()
{
scale_test("test_xdp_loop.o", BPF_PROG_TYPE_XDP, false);
}
void test_verif_scale_seg6_loop()
{
scale_test("test_seg6_loop.o", BPF_PROG_TYPE_LWT_SEG6LOCAL, false);
}
void test_verif_twfw()
{
scale_test("twfw.o", BPF_PROG_TYPE_CGROUP_SKB, false);
}