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// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
#include "vmlinux.h"
#include <bpf/bpf_helpers.h>
#include "bpf_misc.h"
#define HASHMAP_SZ 4194304
struct {
__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
__uint(max_entries, 1000);
__type(key, int);
__type(value, int);
__array(values, struct {
__uint(type, BPF_MAP_TYPE_TASK_STORAGE);
__uint(map_flags, BPF_F_NO_PREALLOC);
__type(key, int);
__type(value, int);
});
} array_of_local_storage_maps SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
__uint(max_entries, 1000);
__type(key, int);
__type(value, int);
__array(values, struct {
__uint(type, BPF_MAP_TYPE_HASH);
__uint(max_entries, HASHMAP_SZ);
__type(key, int);
__type(value, int);
});
} array_of_hash_maps SEC(".maps");
long important_hits;
long hits;
/* set from user-space */
const volatile unsigned int use_hashmap;
const volatile unsigned int hashmap_num_keys;
const volatile unsigned int num_maps;
const volatile unsigned int interleave;
struct loop_ctx {
struct task_struct *task;
long loop_hits;
long loop_important_hits;
};
static int do_lookup(unsigned int elem, struct loop_ctx *lctx)
{
void *map, *inner_map;
int idx = 0;
if (use_hashmap)
map = &array_of_hash_maps;
else
map = &array_of_local_storage_maps;
inner_map = bpf_map_lookup_elem(map, &elem);
if (!inner_map)
return -1;
if (use_hashmap) {
idx = bpf_get_prandom_u32() % hashmap_num_keys;
bpf_map_lookup_elem(inner_map, &idx);
} else {
bpf_task_storage_get(inner_map, lctx->task, &idx,
BPF_LOCAL_STORAGE_GET_F_CREATE);
}
lctx->loop_hits++;
if (!elem)
lctx->loop_important_hits++;
return 0;
}
static long loop(u32 index, void *ctx)
{
struct loop_ctx *lctx = (struct loop_ctx *)ctx;
unsigned int map_idx = index % num_maps;
do_lookup(map_idx, lctx);
if (interleave && map_idx % 3 == 0)
do_lookup(0, lctx);
return 0;
}
SEC("fentry/" SYS_PREFIX "sys_getpgid")
int get_local(void *ctx)
{
struct loop_ctx lctx;
lctx.task = bpf_get_current_task_btf();
lctx.loop_hits = 0;
lctx.loop_important_hits = 0;
bpf_loop(10000, &loop, &lctx, 0);
__sync_add_and_fetch(&hits, lctx.loop_hits);
__sync_add_and_fetch(&important_hits, lctx.loop_important_hits);
return 0;
}
char _license[] SEC("license") = "GPL";
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