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https://github.com/eunomia-bpf/bpf-developer-tutorial.git
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136 lines
2.8 KiB
C
136 lines
2.8 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_core_read.h>
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#include <bpf/bpf_helpers.h>
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#include <bpf/bpf_tracing.h>
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#include "hardirqs.h"
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#include "bits.bpf.h"
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#include "maps.bpf.h"
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#define MAX_ENTRIES 256
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const volatile bool filter_cg = false;
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const volatile bool targ_dist = false;
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const volatile bool targ_ns = false;
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const volatile bool do_count = false;
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struct irq_key {
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char name[32];
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};
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struct {
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__uint(type, BPF_MAP_TYPE_CGROUP_ARRAY);
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__type(key, u32);
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__type(value, u32);
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__uint(max_entries, 1);
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} cgroup_map SEC(".maps");
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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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/// @sample {"interval": 1000, "type" : "log2_hist"}
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struct {
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__uint(type, BPF_MAP_TYPE_HASH);
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__uint(max_entries, MAX_ENTRIES);
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__type(key, struct irq_key);
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__type(value, struct info);
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} infos SEC(".maps");
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static struct info zero;
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static int handle_entry(int irq, struct irqaction *action)
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{
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if (filter_cg && !bpf_current_task_under_cgroup(&cgroup_map, 0))
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return 0;
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if (do_count) {
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struct irq_key key = {};
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struct info *info;
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bpf_probe_read_kernel_str(&key.name, sizeof(key.name), BPF_CORE_READ(action, name));
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info = bpf_map_lookup_or_try_init(&infos, &key, &zero);
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if (!info)
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return 0;
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info->count += 1;
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return 0;
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} else {
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u64 ts = bpf_ktime_get_ns();
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u32 key = 0;
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if (filter_cg && !bpf_current_task_under_cgroup(&cgroup_map, 0))
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return 0;
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bpf_map_update_elem(&start, &key, &ts, BPF_ANY);
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return 0;
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}
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}
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static int handle_exit(int irq, struct irqaction *action)
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{
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struct irq_key ikey = {};
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struct info *info;
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u32 key = 0;
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u64 delta;
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u64 *tsp;
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if (filter_cg && !bpf_current_task_under_cgroup(&cgroup_map, 0))
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return 0;
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tsp = bpf_map_lookup_elem(&start, &key);
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if (!tsp)
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return 0;
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delta = bpf_ktime_get_ns() - *tsp;
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if (!targ_ns)
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delta /= 1000U;
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bpf_probe_read_kernel_str(&ikey.name, sizeof(ikey.name), BPF_CORE_READ(action, name));
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info = bpf_map_lookup_or_try_init(&infos, &ikey, &zero);
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if (!info)
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return 0;
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if (!targ_dist) {
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info->count += delta;
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} else {
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u64 slot;
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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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info->slots[slot]++;
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}
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return 0;
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}
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SEC("tp_btf/irq_handler_entry")
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int BPF_PROG(irq_handler_entry_btf, int irq, struct irqaction *action)
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{
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return handle_entry(irq, action);
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}
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SEC("tp_btf/irq_handler_exit")
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int BPF_PROG(irq_handler_exit_btf, int irq, struct irqaction *action)
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{
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return handle_exit(irq, action);
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}
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SEC("raw_tp/irq_handler_entry")
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int BPF_PROG(irq_handler_entry, int irq, struct irqaction *action)
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{
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return handle_entry(irq, action);
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}
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SEC("raw_tp/irq_handler_exit")
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int BPF_PROG(irq_handler_exit, int irq, struct irqaction *action)
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{
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return handle_exit(irq, action);
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}
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char LICENSE[] SEC("license") = "GPL";
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