68 lines
1.3 KiB
C
68 lines
1.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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// Copyright (c) 2020 Wenbo Zhang
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#include <vmlinux.h>
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#include <bpf/bpf_helpers.h>
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#include <bpf/bpf_tracing.h>
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#include "softirqs.h"
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#include "bits.bpf.h"
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#include "maps.bpf.h"
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const volatile bool targ_dist = false;
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const volatile bool targ_ns = false;
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struct {
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__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
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__uint(max_entries, 1);
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__type(key, u32);
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__type(value, u64);
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} start SEC(".maps");
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__u64 counts[NR_SOFTIRQS] = {};
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struct hist hists[NR_SOFTIRQS] = {};
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SEC("tp_btf/softirq_entry")
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int BPF_PROG(softirq_entry, unsigned int vec_nr)
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{
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u64 ts = bpf_ktime_get_ns();
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u32 key = 0;
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bpf_map_update_elem(&start, &key, &ts, 0);
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return 0;
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}
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SEC("tp_btf/softirq_exit")
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int BPF_PROG(softirq_exit, unsigned int vec_nr)
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{
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u32 key = 0;
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s64 delta;
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u64 *tsp;
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if (vec_nr >= NR_SOFTIRQS)
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return 0;
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tsp = bpf_map_lookup_elem(&start, &key);
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if (!tsp || !*tsp)
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return 0;
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delta = bpf_ktime_get_ns() - *tsp;
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if (delta < 0)
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return 0;
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if (!targ_ns)
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delta /= 1000U;
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if (!targ_dist) {
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__sync_fetch_and_add(&counts[vec_nr], delta);
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} else {
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struct hist *hist;
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u64 slot;
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hist = &hists[vec_nr];
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slot = log2(delta);
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if (slot >= MAX_SLOTS)
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slot = MAX_SLOTS - 1;
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__sync_fetch_and_add(&hist->slots[slot], 1);
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}
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return 0;
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}
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char LICENSE[] SEC("license") = "GPL";
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