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