1 /* Copyright (c) 2016 Facebook
3 * This program is free software; you can redistribute it and/or
4 * modify it under the terms of version 2 of the GNU General Public
5 * License as published by the Free Software Foundation.
7 #include <uapi/linux/bpf.h>
8 #include "bpf_helpers.h"
9 #include <uapi/linux/ptrace.h>
10 #include <uapi/linux/perf_event.h>
11 #include <linux/version.h>
12 #include <linux/sched.h>
14 #define _(P) ({typeof(P) val = 0; bpf_probe_read(&val, sizeof(val), &P); val;})
19 char waker[TASK_COMM_LEN];
20 char target[TASK_COMM_LEN];
25 struct bpf_map_def SEC("maps") counts = {
26 .type = BPF_MAP_TYPE_HASH,
27 .key_size = sizeof(struct key_t),
28 .value_size = sizeof(u64),
32 struct bpf_map_def SEC("maps") start = {
33 .type = BPF_MAP_TYPE_HASH,
34 .key_size = sizeof(u32),
35 .value_size = sizeof(u64),
40 char name[TASK_COMM_LEN];
44 struct bpf_map_def SEC("maps") wokeby = {
45 .type = BPF_MAP_TYPE_HASH,
46 .key_size = sizeof(u32),
47 .value_size = sizeof(struct wokeby_t),
51 struct bpf_map_def SEC("maps") stackmap = {
52 .type = BPF_MAP_TYPE_STACK_TRACE,
53 .key_size = sizeof(u32),
54 .value_size = PERF_MAX_STACK_DEPTH * sizeof(u64),
58 #define STACKID_FLAGS (0 | BPF_F_FAST_STACK_CMP)
60 SEC("kprobe/try_to_wake_up")
61 int waker(struct pt_regs *ctx)
63 struct task_struct *p = (void *) PT_REGS_PARM1(ctx);
64 struct wokeby_t woke = {};
69 bpf_get_current_comm(&woke.name, sizeof(woke.name));
70 woke.ret = bpf_get_stackid(ctx, &stackmap, STACKID_FLAGS);
72 bpf_map_update_elem(&wokeby, &pid, &woke, BPF_ANY);
76 static inline int update_counts(struct pt_regs *ctx, u32 pid, u64 delta)
78 struct key_t key = {};
79 struct wokeby_t *woke;
82 bpf_get_current_comm(&key.target, sizeof(key.target));
83 key.tret = bpf_get_stackid(ctx, &stackmap, STACKID_FLAGS);
85 woke = bpf_map_lookup_elem(&wokeby, &pid);
88 __builtin_memcpy(&key.waker, woke->name, TASK_COMM_LEN);
89 bpf_map_delete_elem(&wokeby, &pid);
92 val = bpf_map_lookup_elem(&counts, &key);
94 bpf_map_update_elem(&counts, &key, &zero, BPF_NOEXIST);
95 val = bpf_map_lookup_elem(&counts, &key);
103 SEC("kprobe/finish_task_switch")
104 int oncpu(struct pt_regs *ctx)
106 struct task_struct *p = (void *) PT_REGS_PARM1(ctx);
110 /* record previous thread sleep time */
112 ts = bpf_ktime_get_ns();
113 bpf_map_update_elem(&start, &pid, &ts, BPF_ANY);
115 /* calculate current thread's delta time */
116 pid = bpf_get_current_pid_tgid();
117 tsp = bpf_map_lookup_elem(&start, &pid);
119 /* missed start or filtered */
122 delta = bpf_ktime_get_ns() - *tsp;
123 bpf_map_delete_elem(&start, &pid);
124 delta = delta / 1000;
125 if (delta < MINBLOCK_US)
128 return update_counts(ctx, pid, delta);
130 char _license[] SEC("license") = "GPL";
131 u32 _version SEC("version") = LINUX_VERSION_CODE;