1// SPDX-License-Identifier: GPL-2.0
  2/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
  3
  4#include "vmlinux.h"
  5#include <bpf/bpf_helpers.h>
  6#include "bpf_misc.h"
  7
  8#define HASHMAP_SZ 4194304
  9
 10struct {
 11	__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
 12	__uint(max_entries, 1000);
 13	__type(key, int);
 14	__type(value, int);
 15	__array(values, struct {
 16		__uint(type, BPF_MAP_TYPE_TASK_STORAGE);
 17		__uint(map_flags, BPF_F_NO_PREALLOC);
 18		__type(key, int);
 19		__type(value, int);
 20	});
 21} array_of_local_storage_maps SEC(".maps");
 22
 23struct {
 24	__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
 25	__uint(max_entries, 1000);
 26	__type(key, int);
 27	__type(value, int);
 28	__array(values, struct {
 29		__uint(type, BPF_MAP_TYPE_HASH);
 30		__uint(max_entries, HASHMAP_SZ);
 31		__type(key, int);
 32		__type(value, int);
 33	});
 34} array_of_hash_maps SEC(".maps");
 35
 36long important_hits;
 37long hits;
 38
 39/* set from user-space */
 40const volatile unsigned int use_hashmap;
 41const volatile unsigned int hashmap_num_keys;
 42const volatile unsigned int num_maps;
 43const volatile unsigned int interleave;
 44
 45struct loop_ctx {
 46	struct task_struct *task;
 47	long loop_hits;
 48	long loop_important_hits;
 49};
 50
 51static int do_lookup(unsigned int elem, struct loop_ctx *lctx)
 52{
 53	void *map, *inner_map;
 54	int idx = 0;
 55
 56	if (use_hashmap)
 57		map = &array_of_hash_maps;
 58	else
 59		map = &array_of_local_storage_maps;
 60
 61	inner_map = bpf_map_lookup_elem(map, &elem);
 62	if (!inner_map)
 63		return -1;
 64
 65	if (use_hashmap) {
 66		idx = bpf_get_prandom_u32() % hashmap_num_keys;
 67		bpf_map_lookup_elem(inner_map, &idx);
 68	} else {
 69		bpf_task_storage_get(inner_map, lctx->task, &idx,
 70				     BPF_LOCAL_STORAGE_GET_F_CREATE);
 71	}
 72
 73	lctx->loop_hits++;
 74	if (!elem)
 75		lctx->loop_important_hits++;
 76	return 0;
 77}
 78
 79static long loop(u32 index, void *ctx)
 80{
 81	struct loop_ctx *lctx = (struct loop_ctx *)ctx;
 82	unsigned int map_idx = index % num_maps;
 83
 84	do_lookup(map_idx, lctx);
 85	if (interleave && map_idx % 3 == 0)
 86		do_lookup(0, lctx);
 87	return 0;
 88}
 89
 90SEC("fentry/" SYS_PREFIX "sys_getpgid")
 91int get_local(void *ctx)
 92{
 93	struct loop_ctx lctx;
 94
 95	lctx.task = bpf_get_current_task_btf();
 96	lctx.loop_hits = 0;
 97	lctx.loop_important_hits = 0;
 98	bpf_loop(10000, &loop, &lctx, 0);
 99	__sync_add_and_fetch(&hits, lctx.loop_hits);
100	__sync_add_and_fetch(&important_hits, lctx.loop_important_hits);
101	return 0;
102}
103
104char _license[] SEC("license") = "GPL";

  1// SPDX-License-Identifier: GPL-2.0
  2/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
  3
  4#include "vmlinux.h"
  5#include <bpf/bpf_helpers.h>
  6#include "bpf_misc.h"
  7
  8#define HASHMAP_SZ 4194304
  9
 10struct {
 11	__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
 12	__uint(max_entries, 1000);
 13	__type(key, int);
 14	__type(value, int);
 15	__array(values, struct {
 16		__uint(type, BPF_MAP_TYPE_TASK_STORAGE);
 17		__uint(map_flags, BPF_F_NO_PREALLOC);
 18		__type(key, int);
 19		__type(value, int);
 20	});
 21} array_of_local_storage_maps SEC(".maps");
 22
 23struct {
 24	__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
 25	__uint(max_entries, 1000);
 26	__type(key, int);
 27	__type(value, int);
 28	__array(values, struct {
 29		__uint(type, BPF_MAP_TYPE_HASH);
 30		__uint(max_entries, HASHMAP_SZ);
 31		__type(key, int);
 32		__type(value, int);
 33	});
 34} array_of_hash_maps SEC(".maps");
 35
 36long important_hits;
 37long hits;
 38
 39/* set from user-space */
 40const volatile unsigned int use_hashmap;
 41const volatile unsigned int hashmap_num_keys;
 42const volatile unsigned int num_maps;
 43const volatile unsigned int interleave;
 44
 45struct loop_ctx {
 46	struct task_struct *task;
 47	long loop_hits;
 48	long loop_important_hits;
 49};
 50
 51static int do_lookup(unsigned int elem, struct loop_ctx *lctx)
 52{
 53	void *map, *inner_map;
 54	int idx = 0;
 55
 56	if (use_hashmap)
 57		map = &array_of_hash_maps;
 58	else
 59		map = &array_of_local_storage_maps;
 60
 61	inner_map = bpf_map_lookup_elem(map, &elem);
 62	if (!inner_map)
 63		return -1;
 64
 65	if (use_hashmap) {
 66		idx = bpf_get_prandom_u32() % hashmap_num_keys;
 67		bpf_map_lookup_elem(inner_map, &idx);
 68	} else {
 69		bpf_task_storage_get(inner_map, lctx->task, &idx,
 70				     BPF_LOCAL_STORAGE_GET_F_CREATE);
 71	}
 72
 73	lctx->loop_hits++;
 74	if (!elem)
 75		lctx->loop_important_hits++;
 76	return 0;
 77}
 78
 79static long loop(u32 index, void *ctx)
 80{
 81	struct loop_ctx *lctx = (struct loop_ctx *)ctx;
 82	unsigned int map_idx = index % num_maps;
 83
 84	do_lookup(map_idx, lctx);
 85	if (interleave && map_idx % 3 == 0)
 86		do_lookup(0, lctx);
 87	return 0;
 88}
 89
 90SEC("fentry/" SYS_PREFIX "sys_getpgid")
 91int get_local(void *ctx)
 92{
 93	struct loop_ctx lctx;
 94
 95	lctx.task = bpf_get_current_task_btf();
 96	lctx.loop_hits = 0;
 97	lctx.loop_important_hits = 0;
 98	bpf_loop(10000, &loop, &lctx, 0);
 99	__sync_add_and_fetch(&hits, lctx.loop_hits);
100	__sync_add_and_fetch(&important_hits, lctx.loop_important_hits);
101	return 0;
102}
103
104char _license[] SEC("license") = "GPL";