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6e1e4a9d60
Introduces stress test for bpf_lru_list that exercises lock-failures and orphan-recovery, added by the LRU rqspinlock conversion. Runs three subtests: common LRU, per-CPU LRU lists (BPF_F_NO_COMMON_LRU), and per-CPU LRU map. Each pins one userspace hammer per CPU and attaches the perf_event NMI BPF prog (update+delete mix) on every online CPU. Pre-fix, lockdep fires the "INITIAL USE -> IN-NMI" splat during stress. After stress test, drain_then_verify_capacity() drains every key and refills the lru map. A stranded node on any CPU's pool would have forced eviction of a just-inserted key on that CPU, surfacing here as a missing lookup. Marked serial_ because per-CPU pinning and high-rate HW perf events would perturb parallel tests. Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com> Link: https://lore.kernel.org/r/20260607-lru_map_spin-v3-3-bcd9332e911b@meta.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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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