Commit | Line | Data |
---|---|---|
35e8e302 SR |
1 | /* |
2 | * trace context switch | |
3 | * | |
4 | * Copyright (C) 2007 Steven Rostedt <srostedt@redhat.com> | |
5 | * | |
6 | */ | |
7 | #include <linux/module.h> | |
35e8e302 SR |
8 | #include <linux/kallsyms.h> |
9 | #include <linux/uaccess.h> | |
35e8e302 | 10 | #include <linux/ftrace.h> |
ad8d75ff | 11 | #include <trace/events/sched.h> |
35e8e302 SR |
12 | |
13 | #include "trace.h" | |
14 | ||
efade6e7 FW |
15 | static int sched_ref; |
16 | static DEFINE_MUTEX(sched_register_mutex); | |
82e04af4 | 17 | |
e309b41d | 18 | static void |
38516ab5 | 19 | probe_sched_switch(void *ignore, struct task_struct *prev, struct task_struct *next) |
35e8e302 | 20 | { |
dcef788e | 21 | if (unlikely(!sched_ref)) |
b07c3f19 MD |
22 | return; |
23 | ||
41bc8144 SR |
24 | tracing_record_cmdline(prev); |
25 | tracing_record_cmdline(next); | |
35e8e302 SR |
26 | } |
27 | ||
4e655519 | 28 | static void |
38516ab5 | 29 | probe_sched_wakeup(void *ignore, struct task_struct *wakee, int success) |
57422797 | 30 | { |
dcef788e | 31 | if (unlikely(!sched_ref)) |
57422797 IM |
32 | return; |
33 | ||
b07c3f19 | 34 | tracing_record_cmdline(current); |
57422797 IM |
35 | } |
36 | ||
5b82a1b0 MD |
37 | static int tracing_sched_register(void) |
38 | { | |
39 | int ret; | |
40 | ||
38516ab5 | 41 | ret = register_trace_sched_wakeup(probe_sched_wakeup, NULL); |
5b82a1b0 | 42 | if (ret) { |
b07c3f19 | 43 | pr_info("wakeup trace: Couldn't activate tracepoint" |
5b82a1b0 MD |
44 | " probe to kernel_sched_wakeup\n"); |
45 | return ret; | |
46 | } | |
47 | ||
38516ab5 | 48 | ret = register_trace_sched_wakeup_new(probe_sched_wakeup, NULL); |
5b82a1b0 | 49 | if (ret) { |
b07c3f19 | 50 | pr_info("wakeup trace: Couldn't activate tracepoint" |
5b82a1b0 MD |
51 | " probe to kernel_sched_wakeup_new\n"); |
52 | goto fail_deprobe; | |
53 | } | |
54 | ||
38516ab5 | 55 | ret = register_trace_sched_switch(probe_sched_switch, NULL); |
5b82a1b0 | 56 | if (ret) { |
b07c3f19 | 57 | pr_info("sched trace: Couldn't activate tracepoint" |
73d8b8bc | 58 | " probe to kernel_sched_switch\n"); |
5b82a1b0 MD |
59 | goto fail_deprobe_wake_new; |
60 | } | |
61 | ||
62 | return ret; | |
63 | fail_deprobe_wake_new: | |
38516ab5 | 64 | unregister_trace_sched_wakeup_new(probe_sched_wakeup, NULL); |
5b82a1b0 | 65 | fail_deprobe: |
38516ab5 | 66 | unregister_trace_sched_wakeup(probe_sched_wakeup, NULL); |
5b82a1b0 MD |
67 | return ret; |
68 | } | |
69 | ||
70 | static void tracing_sched_unregister(void) | |
71 | { | |
38516ab5 SR |
72 | unregister_trace_sched_switch(probe_sched_switch, NULL); |
73 | unregister_trace_sched_wakeup_new(probe_sched_wakeup, NULL); | |
74 | unregister_trace_sched_wakeup(probe_sched_wakeup, NULL); | |
5b82a1b0 MD |
75 | } |
76 | ||
f2252935 | 77 | static void tracing_start_sched_switch(void) |
5b82a1b0 | 78 | { |
efade6e7 | 79 | mutex_lock(&sched_register_mutex); |
e168e051 | 80 | if (!(sched_ref++)) |
5b82a1b0 | 81 | tracing_sched_register(); |
efade6e7 | 82 | mutex_unlock(&sched_register_mutex); |
5b82a1b0 MD |
83 | } |
84 | ||
f2252935 | 85 | static void tracing_stop_sched_switch(void) |
5b82a1b0 | 86 | { |
efade6e7 | 87 | mutex_lock(&sched_register_mutex); |
e168e051 | 88 | if (!(--sched_ref)) |
5b82a1b0 | 89 | tracing_sched_unregister(); |
efade6e7 | 90 | mutex_unlock(&sched_register_mutex); |
5b82a1b0 MD |
91 | } |
92 | ||
41bc8144 SR |
93 | void tracing_start_cmdline_record(void) |
94 | { | |
95 | tracing_start_sched_switch(); | |
96 | } | |
97 | ||
98 | void tracing_stop_cmdline_record(void) | |
99 | { | |
100 | tracing_stop_sched_switch(); | |
101 | } |