34 lines
695 B
C
34 lines
695 B
C
// SPDX-License-Identifier: GPL-2.0
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#include <vmlinux.h>
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#include <bpf/bpf_helpers.h>
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struct {
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__uint(type, BPF_MAP_TYPE_LRU_HASH);
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__uint(max_entries, 64);
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__type(key, __u32);
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__type(value, __u64);
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} lru_map SEC(".maps");
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int hits;
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SEC("perf_event")
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int oncpu(void *ctx)
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{
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/*
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* Key range deliberately wider than max_entries to force LRU
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* eviction on every other update.
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*/
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__u32 key = bpf_get_prandom_u32() % 128;
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bool do_update = bpf_get_prandom_u32() & 1;
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__u64 val = 1;
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if (do_update)
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bpf_map_update_elem(&lru_map, &key, &val, BPF_ANY);
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else
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bpf_map_delete_elem(&lru_map, &key);
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__sync_fetch_and_add(&hits, 1);
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return 0;
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}
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char _license[] SEC("license") = "GPL";
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