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Diffstat (limited to 'samples/bpf/test_lru_dist.c')
| -rw-r--r-- | samples/bpf/test_lru_dist.c | 539 |
1 files changed, 539 insertions, 0 deletions
diff --git a/samples/bpf/test_lru_dist.c b/samples/bpf/test_lru_dist.c new file mode 100644 index 000000000..5efb91763 --- /dev/null +++ b/samples/bpf/test_lru_dist.c @@ -0,0 +1,539 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2016 Facebook + */ +#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 <bpf/bpf.h> +#include "bpf_util.h" + +#define min(a, b) ((a) < (b) ? (a) : (b)) +#ifndef offsetof +# define offsetof(TYPE, MEMBER) ((size_t)&((TYPE *)0)->MEMBER) +#endif +#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_map_create(BPF_MAP_TYPE_HASH, NULL, + sizeof(unsigned long long), + sizeof(struct pfect_lru_node *), + nr_possible_elems, NULL); + 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_map_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_map_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_map_update_elem(lru->map_fd, &key, &node, BPF_EXIST)); + } else { + lru->nr_unique++; + assert(!bpf_map_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) +{ + LIBBPF_OPTS(bpf_map_create_opts, opts, + .map_flags = map_flags, + ); + int map_fd; + + map_fd = bpf_map_create(map_type, NULL, sizeof(unsigned long long), + sizeof(unsigned long long), size, &opts); + + 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_map_lookup_elem(lru_map_fd, &key, &value)) + continue; + + if (bpf_map_update_elem(lru_map_fd, &key, &value, BPF_NOEXIST)) { + printf("bpf_map_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_map_update_elem(map_fd, &key, value, BPF_NOEXIST) == 0); + + start_key = 101; + end_key = min(key, 900); + + while (start_key <= end_key) { + bpf_map_lookup_elem(map_fd, &start_key, value); + start_key++; + } + } + + for (key = 1; key <= 1000; key++) { + if (bpf_map_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_map_update_elem(map_fd, &key, value, BPF_NOEXIST)); + + for (key = 1; key <= 1000; key++) { + if (bpf_map_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_map_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_map_lookup_elem(map_fd, &key, value); + } else { + bpf_map_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_map_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) +{ + int map_flags[] = {0, BPF_F_NO_COMMON_LRU}; + const char *dist_file; + int nr_tasks = 1; + int lru_size; + int f; + + if (argc < 4) { + printf("Usage: %s <dist-file> <lru-size> <nr-tasks>\n", + argv[0]); + return -1; + } + + dist_file = argv[1]; + lru_size = atoi(argv[2]); + nr_tasks = atoi(argv[3]); + + setbuf(stdout, NULL); + + srand(time(NULL)); + + nr_cpus = bpf_num_possible_cpus(); + assert(nr_cpus != -1); + printf("nr_cpus:%d\n\n", nr_cpus); + + nr_tasks = min(nr_tasks, nr_cpus); + + dist_key_counts = read_keys(dist_file, &dist_keys); + if (!dist_key_counts) { + printf("%s has no key\n", dist_file); + return -1; + } + + for (f = 0; f < ARRAY_SIZE(map_flags); f++) { + test_lru_loss0(BPF_MAP_TYPE_LRU_HASH, map_flags[f]); + test_lru_loss1(BPF_MAP_TYPE_LRU_HASH, map_flags[f]); + test_parallel_lru_loss(BPF_MAP_TYPE_LRU_HASH, map_flags[f], + nr_tasks); + test_parallel_lru_dist(BPF_MAP_TYPE_LRU_HASH, map_flags[f], + nr_tasks, lru_size); + printf("\n"); + } + + free(dist_keys); + + return 0; +} |