Commit 5db58faf authored by Martin KaFai Lau's avatar Martin KaFai Lau Committed by David S. Miller
Browse files

bpf: Add tests for the LRU bpf_htab

This patch has some unit tests and a test_lru_dist.

The test_lru_dist reads in the numeric keys from a file.
The files used here are generated by a modified fio-genzipf tool
originated from the fio test suit.  The sample data file can be
found here: https://github.com/iamkafai/bpf-lru



The zipf.* data files have 100k numeric keys and the key is also
ranged from 1 to 100k.

The test_lru_dist outputs the number of unique keys (nr_unique).
F.e. The following means, 61239 of them is unique out of 100k keys.
nr_misses means it cannot be found in the LRU map, so nr_misses
must be >= nr_unique. test_lru_dist also simulates a perfect LRU
map as a comparison:

[root@arch-fb-vm1 ~]# ~/devshare/fb-kernel/linux/samples/bpf/test_lru_dist \
/root/zipf.100k.a1_01.out 4000 1
...
test_parallel_lru_dist (map_type:9 map_flags:0x0):
    task:0 BPF LRU: nr_unique:23093(/100000) nr_misses:31603(/100000)
    task:0 Perfect LRU: nr_unique:23093(/100000 nr_misses:34328(/100000)
....
test_parallel_lru_dist (map_type:9 map_flags:0x2):
    task:0 BPF LRU: nr_unique:23093(/100000) nr_misses:31710(/100000)
    task:0 Perfect LRU: nr_unique:23093(/100000 nr_misses:34328(/100000)

[root@arch-fb-vm1 ~]# ~/devshare/fb-kernel/linux/samples/bpf/test_lru_dist \
/root/zipf.100k.a0_01.out 40000 1
...
test_parallel_lru_dist (map_type:9 map_flags:0x0):
    task:0 BPF LRU: nr_unique:61239(/100000) nr_misses:67054(/100000)
    task:0 Perfect LRU: nr_unique:61239(/100000 nr_misses:66993(/100000)
...
test_parallel_lru_dist (map_type:9 map_flags:0x2):
    task:0 BPF LRU: nr_unique:61239(/100000) nr_misses:67068(/100000)
    task:0 Perfect LRU: nr_unique:61239(/100000 nr_misses:66993(/100000)

LRU map has also been added to map_perf_test:
/* Global LRU */
[root@kerneltest003.31.prn1 ~]# for i in 1 4 8; do echo -n "$i cpus: "; \
./map_perf_test 16 $i | awk '{r += $3}END{print r " updates"}'; done
 1 cpus: 2934082 updates
 4 cpus: 7391434 updates
 8 cpus: 6500576 updates

/* Percpu LRU */
[root@kerneltest003.31.prn1 ~]# for i in 1 4 8; do echo -n "$i cpus: "; \
./map_perf_test 32 $i | awk '{r += $3}END{print r " updates"}'; done
  1 cpus: 2896553 updates
  4 cpus: 9766395 updates
  8 cpus: 17460553 updates
Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8f844938
......@@ -2,6 +2,7 @@
obj- := dummy.o
# List of programs to build
hostprogs-y := test_lru_dist
hostprogs-y += sock_example
hostprogs-y += fds_example
hostprogs-y += sockex1
......@@ -28,6 +29,7 @@ hostprogs-y += trace_event
hostprogs-y += sampleip
hostprogs-y += tc_l2_redirect
test_lru_dist-objs := test_lru_dist.o libbpf.o
sock_example-objs := sock_example.o libbpf.o
fds_example-objs := bpf_load.o libbpf.o fds_example.o
sockex1-objs := bpf_load.o libbpf.o sockex1_user.o
......
......@@ -19,6 +19,21 @@ struct bpf_map_def SEC("maps") hash_map = {
.max_entries = MAX_ENTRIES,
};
struct bpf_map_def 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 SEC("maps") percpu_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 SEC("maps") percpu_hash_map = {
.type = BPF_MAP_TYPE_PERCPU_HASH,
.key_size = sizeof(u32),
......@@ -53,6 +68,7 @@ int stress_hmap(struct pt_regs *ctx)
value = bpf_map_lookup_elem(&hash_map, &key);
if (value)
bpf_map_delete_elem(&hash_map, &key);
return 0;
}
......@@ -96,5 +112,28 @@ int stress_percpu_hmap_alloc(struct pt_regs *ctx)
bpf_map_delete_elem(&percpu_hash_map_alloc, &key);
return 0;
}
SEC("kprobe/sys_getpid")
int stress_lru_hmap_alloc(struct pt_regs *ctx)
{
u32 key = bpf_get_prandom_u32();
long val = 1;
bpf_map_update_elem(&lru_hash_map, &key, &val, BPF_ANY);
return 0;
}
SEC("kprobe/sys_getppid")
int stress_percpu_lru_hmap_alloc(struct pt_regs *ctx)
{
u32 key = bpf_get_prandom_u32();
long val = 1;
bpf_map_update_elem(&percpu_lru_hash_map, &key, &val, BPF_ANY);
return 0;
}
char _license[] SEC("license") = "GPL";
u32 _version SEC("version") = LINUX_VERSION_CODE;
......@@ -35,6 +35,8 @@ static __u64 time_get_ns(void)
#define PERCPU_HASH_PREALLOC (1 << 1)
#define HASH_KMALLOC (1 << 2)
#define PERCPU_HASH_KMALLOC (1 << 3)
#define LRU_HASH_PREALLOC (1 << 4)
#define PERCPU_LRU_HASH_PREALLOC (1 << 5)
static int test_flags = ~0;
......@@ -50,6 +52,30 @@ static void test_hash_prealloc(int cpu)
cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
}
static void test_lru_hash_prealloc(int cpu)
{
__u64 start_time;
int i;
start_time = time_get_ns();
for (i = 0; i < MAX_CNT; i++)
syscall(__NR_getpid);
printf("%d:lru_hash_map_perf pre-alloc %lld events per sec\n",
cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
}
static void test_percpu_lru_hash_prealloc(int cpu)
{
__u64 start_time;
int i;
start_time = time_get_ns();
for (i = 0; i < MAX_CNT; i++)
syscall(__NR_getppid);
printf("%d:lru_hash_map_perf pre-alloc %lld events per sec\n",
cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
}
static void test_percpu_hash_prealloc(int cpu)
{
__u64 start_time;
......@@ -105,6 +131,12 @@ static void loop(int 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 & PERCPU_LRU_HASH_PREALLOC)
test_percpu_lru_hash_prealloc(cpu);
}
static void run_perf_test(int tasks)
......
/*
* Copyright (c) 2016 Facebook
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*/
#define _GNU_SOURCE
#include <linux/types.h>
#include <stdio.h>
#include <unistd.h>
#include <linux/bpf.h>
#include <errno.h>
#include <string.h>
#include <assert.h>
#include <sched.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#include <time.h>
#include "libbpf.h"
#define min(a, b) ((a) < (b) ? (a) : (b))
#define offsetof(TYPE, MEMBER) ((size_t)&((TYPE *)0)->MEMBER)
#define container_of(ptr, type, member) ({ \
const typeof( ((type *)0)->member ) *__mptr = (ptr); \
(type *)( (char *)__mptr - offsetof(type,member) );})
static int nr_cpus;
static unsigned long long *dist_keys;
static unsigned int dist_key_counts;
struct list_head {
struct list_head *next, *prev;
};
static inline void INIT_LIST_HEAD(struct list_head *list)
{
list->next = list;
list->prev = list;
}
static inline int list_empty(const struct list_head *head)
{
return head->next == head;
}
static inline void __list_add(struct list_head *new,
struct list_head *prev,
struct list_head *next)
{
next->prev = new;
new->next = next;
new->prev = prev;
prev->next = new;
}
static inline void list_add(struct list_head *new, struct list_head *head)
{
__list_add(new, head, head->next);
}
static inline void __list_del(struct list_head *prev, struct list_head *next)
{
next->prev = prev;
prev->next = next;
}
static inline void __list_del_entry(struct list_head *entry)
{
__list_del(entry->prev, entry->next);
}
static inline void list_move(struct list_head *list, struct list_head *head)
{
__list_del_entry(list);
list_add(list, head);
}
#define list_entry(ptr, type, member) \
container_of(ptr, type, member)
#define list_last_entry(ptr, type, member) \
list_entry((ptr)->prev, type, member)
struct pfect_lru_node {
struct list_head list;
unsigned long long key;
};
struct pfect_lru {
struct list_head list;
struct pfect_lru_node *free_nodes;
unsigned int cur_size;
unsigned int lru_size;
unsigned int nr_unique;
unsigned int nr_misses;
unsigned int total;
int map_fd;
};
static void pfect_lru_init(struct pfect_lru *lru, unsigned int lru_size,
unsigned int nr_possible_elems)
{
lru->map_fd = bpf_create_map(BPF_MAP_TYPE_HASH,
sizeof(unsigned long long),
sizeof(struct pfect_lru_node *),
nr_possible_elems, 0);
assert(lru->map_fd != -1);
lru->free_nodes = malloc(lru_size * sizeof(struct pfect_lru_node));
assert(lru->free_nodes);
INIT_LIST_HEAD(&lru->list);
lru->cur_size = 0;
lru->lru_size = lru_size;
lru->nr_unique = lru->nr_misses = lru->total = 0;
}
static void pfect_lru_destroy(struct pfect_lru *lru)
{
close(lru->map_fd);
free(lru->free_nodes);
}
static int pfect_lru_lookup_or_insert(struct pfect_lru *lru,
unsigned long long key)
{
struct pfect_lru_node *node = NULL;
int seen = 0;
lru->total++;
if (!bpf_lookup_elem(lru->map_fd, &key, &node)) {
if (node) {
list_move(&node->list, &lru->list);
return 1;
}
seen = 1;
}
if (lru->cur_size < lru->lru_size) {
node = &lru->free_nodes[lru->cur_size++];
INIT_LIST_HEAD(&node->list);
} else {
struct pfect_lru_node *null_node = NULL;
node = list_last_entry(&lru->list,
struct pfect_lru_node,
list);
bpf_update_elem(lru->map_fd, &node->key, &null_node, BPF_EXIST);
}
node->key = key;
list_move(&node->list, &lru->list);
lru->nr_misses++;
if (seen) {
assert(!bpf_update_elem(lru->map_fd, &key, &node, BPF_EXIST));
} else {
lru->nr_unique++;
assert(!bpf_update_elem(lru->map_fd, &key, &node, BPF_NOEXIST));
}
return seen;
}
static unsigned int read_keys(const char *dist_file,
unsigned long long **keys)
{
struct stat fst;
unsigned long long *retkeys;
unsigned int counts = 0;
int dist_fd;
char *b, *l;
int i;
dist_fd = open(dist_file, 0);
assert(dist_fd != -1);
assert(fstat(dist_fd, &fst) == 0);
b = malloc(fst.st_size);
assert(b);
assert(read(dist_fd, b, fst.st_size) == fst.st_size);
close(dist_fd);
for (i = 0; i < fst.st_size; i++) {
if (b[i] == '\n')
counts++;
}
counts++; /* in case the last line has no \n */
retkeys = malloc(counts * sizeof(unsigned long long));
assert(retkeys);
counts = 0;
for (l = strtok(b, "\n"); l; l = strtok(NULL, "\n"))
retkeys[counts++] = strtoull(l, NULL, 10);
free(b);
*keys = retkeys;
return counts;
}
static int create_map(int map_type, int map_flags, unsigned int size)
{
int map_fd;
map_fd = bpf_create_map(map_type, sizeof(unsigned long long),
sizeof(unsigned long long), size, map_flags);
if (map_fd == -1)
perror("bpf_create_map");
return map_fd;
}
static int sched_next_online(int pid, int next_to_try)
{
cpu_set_t cpuset;
if (next_to_try == nr_cpus)
return -1;
while (next_to_try < nr_cpus) {
CPU_ZERO(&cpuset);
CPU_SET(next_to_try++, &cpuset);
if (!sched_setaffinity(pid, sizeof(cpuset), &cpuset))
break;
}
return next_to_try;
}
static void run_parallel(unsigned int tasks, void (*fn)(int i, void *data),
void *data)
{
int next_sched_cpu = 0;
pid_t pid[tasks];
int i;
for (i = 0; i < tasks; i++) {
pid[i] = fork();
if (pid[i] == 0) {
next_sched_cpu = sched_next_online(0, next_sched_cpu);
fn(i, data);
exit(0);
} else if (pid[i] == -1) {
printf("couldn't spawn #%d process\n", i);
exit(1);
}
/* It is mostly redundant and just allow the parent
* process to update next_shced_cpu for the next child
* process
*/
next_sched_cpu = sched_next_online(pid[i], next_sched_cpu);
}
for (i = 0; i < tasks; i++) {
int status;
assert(waitpid(pid[i], &status, 0) == pid[i]);
assert(status == 0);
}
}
static void do_test_lru_dist(int task, void *data)
{
unsigned int nr_misses = 0;
struct pfect_lru pfect_lru;
unsigned long long key, value = 1234;
unsigned int i;
unsigned int lru_map_fd = ((unsigned int *)data)[0];
unsigned int lru_size = ((unsigned int *)data)[1];
unsigned long long key_offset = task * dist_key_counts;
pfect_lru_init(&pfect_lru, lru_size, dist_key_counts);
for (i = 0; i < dist_key_counts; i++) {
key = dist_keys[i] + key_offset;
pfect_lru_lookup_or_insert(&pfect_lru, key);
if (!bpf_lookup_elem(lru_map_fd, &key, &value))
continue;
if (bpf_update_elem(lru_map_fd, &key, &value, BPF_NOEXIST)) {
printf("bpf_update_elem(lru_map_fd, %llu): errno:%d\n",
key, errno);
assert(0);
}
nr_misses++;
}
printf(" task:%d BPF LRU: nr_unique:%u(/%u) nr_misses:%u(/%u)\n",
task, pfect_lru.nr_unique, dist_key_counts, nr_misses,
dist_key_counts);
printf(" task:%d Perfect LRU: nr_unique:%u(/%u) nr_misses:%u(/%u)\n",
task, pfect_lru.nr_unique, pfect_lru.total,
pfect_lru.nr_misses, pfect_lru.total);
pfect_lru_destroy(&pfect_lru);
close(lru_map_fd);
}
static void test_parallel_lru_dist(int map_type, int map_flags,
int nr_tasks, unsigned int lru_size)
{
int child_data[2];
int lru_map_fd;
printf("%s (map_type:%d map_flags:0x%X):\n", __func__, map_type,
map_flags);
if (map_flags & BPF_F_NO_COMMON_LRU)
lru_map_fd = create_map(map_type, map_flags,
nr_cpus * lru_size);
else
lru_map_fd = create_map(map_type, map_flags,
nr_tasks * lru_size);
assert(lru_map_fd != -1);
child_data[0] = lru_map_fd;
child_data[1] = lru_size;
run_parallel(nr_tasks, do_test_lru_dist, child_data);
close(lru_map_fd);
}
static void test_lru_loss0(int map_type, int map_flags)
{
unsigned long long key, value[nr_cpus];
unsigned int old_unused_losses = 0;
unsigned int new_unused_losses = 0;
unsigned int used_losses = 0;
int map_fd;
printf("%s (map_type:%d map_flags:0x%X): ", __func__, map_type,
map_flags);
assert(sched_next_online(0, 0) != -1);
if (map_flags & BPF_F_NO_COMMON_LRU)
map_fd = create_map(map_type, map_flags, 900 * nr_cpus);
else
map_fd = create_map(map_type, map_flags, 900);
assert(map_fd != -1);
value[0] = 1234;
for (key = 1; key <= 1000; key++) {
int start_key, end_key;
assert(bpf_update_elem(map_fd, &key, value, BPF_NOEXIST) == 0);
start_key = 101;
end_key = min(key, 900);
while (start_key <= end_key) {
bpf_lookup_elem(map_fd, &start_key, value);
start_key++;
}
}
for (key = 1; key <= 1000; key++) {
if (bpf_lookup_elem(map_fd, &key, value)) {
if (key <= 100)
old_unused_losses++;
else if (key <= 900)
used_losses++;
else
new_unused_losses++;
}
}
close(map_fd);
printf("older-elem-losses:%d(/100) active-elem-losses:%d(/800) "
"newer-elem-losses:%d(/100)\n",
old_unused_losses, used_losses, new_unused_losses);
}
static void test_lru_loss1(int map_type, int map_flags)
{
unsigned long long key, value[nr_cpus];
int map_fd;
unsigned int nr_losses = 0;
printf("%s (map_type:%d map_flags:0x%X): ", __func__, map_type,
map_flags);
assert(sched_next_online(0, 0) != -1);
if (map_flags & BPF_F_NO_COMMON_LRU)
map_fd = create_map(map_type, map_flags, 1000 * nr_cpus);
else
map_fd = create_map(map_type, map_flags, 1000);
assert(map_fd != -1);
value[0] = 1234;
for (key = 1; key <= 1000; key++)
assert(!bpf_update_elem(map_fd, &key, value, BPF_NOEXIST));
for (key = 1; key <= 1000; key++) {
if (bpf_lookup_elem(map_fd, &key, value))
nr_losses++;
}
close(map_fd);
printf("nr_losses:%d(/1000)\n", nr_losses);
}
static void do_test_parallel_lru_loss(int task, void *data)
{
const unsigned int nr_stable_elems = 1000;
const unsigned int nr_repeats = 100000;
int map_fd = *(int *)data;
unsigned long long stable_base;
unsigned long long key, value[nr_cpus];
unsigned long long next_ins_key;
unsigned int nr_losses = 0;
unsigned int i;
stable_base = task * nr_repeats * 2 + 1;
next_ins_key = stable_base;
value[0] = 1234;
for (i = 0; i < nr_stable_elems; i++) {
assert(bpf_update_elem(map_fd, &next_ins_key, value,
BPF_NOEXIST) == 0);
next_ins_key++;
}
for (i = 0; i < nr_repeats; i++) {
int rn;
rn = rand();
if (rn % 10) {
key = rn % nr_stable_elems + stable_base;
bpf_lookup_elem(map_fd, &key, value);
} else {
bpf_update_elem(map_fd, &next_ins_key, value,
BPF_NOEXIST);
next_ins_key++;
}
}
key = stable_base;
for (i = 0; i < nr_stable_elems; i++) {
if (bpf_lookup_elem(map_fd, &key, value))
nr_losses++;
key++;
}
printf(" task:%d nr_losses:%u\n", task, nr_losses);
}
static void test_parallel_lru_loss(int map_type, int map_flags, int nr_tasks)
{
int map_fd;
printf("%s (map_type:%d map_flags:0x%X):\n", __func__, map_type,
map_flags);
/* Give 20% more than the active working set */
if (map_flags & BPF_F_NO_COMMON_LRU)
map_fd = create_map(map_type, map_flags,
nr_cpus * (1000 + 200));
else
map_fd = create_map(map_type, map_flags,
nr_tasks * (1000 + 200));
assert(map_fd != -1);
run_parallel(nr_tasks, do_test_parallel_lru_loss, &map_fd);
close(map_fd);
}
int main(int argc, char **argv)
{
struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
int map_flags[] = {0, BPF_F_NO_COMMON_LRU};
const char *dist_file;
int nr_tasks = 1;
int lru_size;
int f;