Loading...
1/* Copyright (c) 2016 Facebook
2 *
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.
6 */
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>
13
14#define _(P) ({typeof(P) val = 0; bpf_probe_read(&val, sizeof(val), &P); val;})
15
16#define MINBLOCK_US 1
17
18struct key_t {
19 char waker[TASK_COMM_LEN];
20 char target[TASK_COMM_LEN];
21 u32 wret;
22 u32 tret;
23};
24
25struct bpf_map_def SEC("maps") counts = {
26 .type = BPF_MAP_TYPE_HASH,
27 .key_size = sizeof(struct key_t),
28 .value_size = sizeof(u64),
29 .max_entries = 10000,
30};
31
32struct bpf_map_def SEC("maps") start = {
33 .type = BPF_MAP_TYPE_HASH,
34 .key_size = sizeof(u32),
35 .value_size = sizeof(u64),
36 .max_entries = 10000,
37};
38
39struct wokeby_t {
40 char name[TASK_COMM_LEN];
41 u32 ret;
42};
43
44struct bpf_map_def SEC("maps") wokeby = {
45 .type = BPF_MAP_TYPE_HASH,
46 .key_size = sizeof(u32),
47 .value_size = sizeof(struct wokeby_t),
48 .max_entries = 10000,
49};
50
51struct 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),
55 .max_entries = 10000,
56};
57
58#define STACKID_FLAGS (0 | BPF_F_FAST_STACK_CMP)
59
60SEC("kprobe/try_to_wake_up")
61int waker(struct pt_regs *ctx)
62{
63 struct task_struct *p = (void *) PT_REGS_PARM1(ctx);
64 struct wokeby_t woke = {};
65 u32 pid;
66
67 pid = _(p->pid);
68
69 bpf_get_current_comm(&woke.name, sizeof(woke.name));
70 woke.ret = bpf_get_stackid(ctx, &stackmap, STACKID_FLAGS);
71
72 bpf_map_update_elem(&wokeby, &pid, &woke, BPF_ANY);
73 return 0;
74}
75
76static inline int update_counts(struct pt_regs *ctx, u32 pid, u64 delta)
77{
78 struct key_t key = {};
79 struct wokeby_t *woke;
80 u64 zero = 0, *val;
81
82 bpf_get_current_comm(&key.target, sizeof(key.target));
83 key.tret = bpf_get_stackid(ctx, &stackmap, STACKID_FLAGS);
84
85 woke = bpf_map_lookup_elem(&wokeby, &pid);
86 if (woke) {
87 key.wret = woke->ret;
88 __builtin_memcpy(&key.waker, woke->name, TASK_COMM_LEN);
89 bpf_map_delete_elem(&wokeby, &pid);
90 }
91
92 val = bpf_map_lookup_elem(&counts, &key);
93 if (!val) {
94 bpf_map_update_elem(&counts, &key, &zero, BPF_NOEXIST);
95 val = bpf_map_lookup_elem(&counts, &key);
96 if (!val)
97 return 0;
98 }
99 (*val) += delta;
100 return 0;
101}
102
103SEC("kprobe/finish_task_switch")
104int oncpu(struct pt_regs *ctx)
105{
106 struct task_struct *p = (void *) PT_REGS_PARM1(ctx);
107 u64 delta, ts, *tsp;
108 u32 pid;
109
110 /* record previous thread sleep time */
111 pid = _(p->pid);
112 ts = bpf_ktime_get_ns();
113 bpf_map_update_elem(&start, &pid, &ts, BPF_ANY);
114
115 /* calculate current thread's delta time */
116 pid = bpf_get_current_pid_tgid();
117 tsp = bpf_map_lookup_elem(&start, &pid);
118 if (!tsp)
119 /* missed start or filtered */
120 return 0;
121
122 delta = bpf_ktime_get_ns() - *tsp;
123 bpf_map_delete_elem(&start, &pid);
124 delta = delta / 1000;
125 if (delta < MINBLOCK_US)
126 return 0;
127
128 return update_counts(ctx, pid, delta);
129}
130char _license[] SEC("license") = "GPL";
131u32 _version SEC("version") = LINUX_VERSION_CODE;
1/* Copyright (c) 2016 Facebook
2 *
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.
6 */
7#include <uapi/linux/bpf.h>
8#include <uapi/linux/ptrace.h>
9#include <uapi/linux/perf_event.h>
10#include <linux/version.h>
11#include <linux/sched.h>
12#include <bpf/bpf_helpers.h>
13#include <bpf/bpf_tracing.h>
14
15#define _(P) \
16 ({ \
17 typeof(P) val; \
18 bpf_probe_read_kernel(&val, sizeof(val), &(P)); \
19 val; \
20 })
21
22#define MINBLOCK_US 1
23
24struct key_t {
25 char waker[TASK_COMM_LEN];
26 char target[TASK_COMM_LEN];
27 u32 wret;
28 u32 tret;
29};
30
31struct bpf_map_def SEC("maps") counts = {
32 .type = BPF_MAP_TYPE_HASH,
33 .key_size = sizeof(struct key_t),
34 .value_size = sizeof(u64),
35 .max_entries = 10000,
36};
37
38struct bpf_map_def SEC("maps") start = {
39 .type = BPF_MAP_TYPE_HASH,
40 .key_size = sizeof(u32),
41 .value_size = sizeof(u64),
42 .max_entries = 10000,
43};
44
45struct wokeby_t {
46 char name[TASK_COMM_LEN];
47 u32 ret;
48};
49
50struct bpf_map_def SEC("maps") wokeby = {
51 .type = BPF_MAP_TYPE_HASH,
52 .key_size = sizeof(u32),
53 .value_size = sizeof(struct wokeby_t),
54 .max_entries = 10000,
55};
56
57struct bpf_map_def SEC("maps") stackmap = {
58 .type = BPF_MAP_TYPE_STACK_TRACE,
59 .key_size = sizeof(u32),
60 .value_size = PERF_MAX_STACK_DEPTH * sizeof(u64),
61 .max_entries = 10000,
62};
63
64#define STACKID_FLAGS (0 | BPF_F_FAST_STACK_CMP)
65
66SEC("kprobe/try_to_wake_up")
67int waker(struct pt_regs *ctx)
68{
69 struct task_struct *p = (void *) PT_REGS_PARM1(ctx);
70 struct wokeby_t woke;
71 u32 pid;
72
73 pid = _(p->pid);
74
75 bpf_get_current_comm(&woke.name, sizeof(woke.name));
76 woke.ret = bpf_get_stackid(ctx, &stackmap, STACKID_FLAGS);
77
78 bpf_map_update_elem(&wokeby, &pid, &woke, BPF_ANY);
79 return 0;
80}
81
82static inline int update_counts(void *ctx, u32 pid, u64 delta)
83{
84 struct wokeby_t *woke;
85 u64 zero = 0, *val;
86 struct key_t key;
87
88 __builtin_memset(&key.waker, 0, sizeof(key.waker));
89 bpf_get_current_comm(&key.target, sizeof(key.target));
90 key.tret = bpf_get_stackid(ctx, &stackmap, STACKID_FLAGS);
91 key.wret = 0;
92
93 woke = bpf_map_lookup_elem(&wokeby, &pid);
94 if (woke) {
95 key.wret = woke->ret;
96 __builtin_memcpy(&key.waker, woke->name, sizeof(key.waker));
97 bpf_map_delete_elem(&wokeby, &pid);
98 }
99
100 val = bpf_map_lookup_elem(&counts, &key);
101 if (!val) {
102 bpf_map_update_elem(&counts, &key, &zero, BPF_NOEXIST);
103 val = bpf_map_lookup_elem(&counts, &key);
104 if (!val)
105 return 0;
106 }
107 (*val) += delta;
108 return 0;
109}
110
111#if 1
112/* taken from /sys/kernel/debug/tracing/events/sched/sched_switch/format */
113struct sched_switch_args {
114 unsigned long long pad;
115 char prev_comm[16];
116 int prev_pid;
117 int prev_prio;
118 long long prev_state;
119 char next_comm[16];
120 int next_pid;
121 int next_prio;
122};
123SEC("tracepoint/sched/sched_switch")
124int oncpu(struct sched_switch_args *ctx)
125{
126 /* record previous thread sleep time */
127 u32 pid = ctx->prev_pid;
128#else
129SEC("kprobe/finish_task_switch")
130int oncpu(struct pt_regs *ctx)
131{
132 struct task_struct *p = (void *) PT_REGS_PARM1(ctx);
133 /* record previous thread sleep time */
134 u32 pid = _(p->pid);
135#endif
136 u64 delta, ts, *tsp;
137
138 ts = bpf_ktime_get_ns();
139 bpf_map_update_elem(&start, &pid, &ts, BPF_ANY);
140
141 /* calculate current thread's delta time */
142 pid = bpf_get_current_pid_tgid();
143 tsp = bpf_map_lookup_elem(&start, &pid);
144 if (!tsp)
145 /* missed start or filtered */
146 return 0;
147
148 delta = bpf_ktime_get_ns() - *tsp;
149 bpf_map_delete_elem(&start, &pid);
150 delta = delta / 1000;
151 if (delta < MINBLOCK_US)
152 return 0;
153
154 return update_counts(ctx, pid, delta);
155}
156char _license[] SEC("license") = "GPL";
157u32 _version SEC("version") = LINUX_VERSION_CODE;