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Commit | Line | Data |
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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 |
c73464b1 PZ |
19 | probe_sched_switch(void *ignore, bool preempt, |
20 | struct task_struct *prev, struct task_struct *next) | |
35e8e302 | 21 | { |
dcef788e | 22 | if (unlikely(!sched_ref)) |
b07c3f19 MD |
23 | return; |
24 | ||
41bc8144 SR |
25 | tracing_record_cmdline(prev); |
26 | tracing_record_cmdline(next); | |
35e8e302 SR |
27 | } |
28 | ||
4e655519 | 29 | static void |
fbd705a0 | 30 | probe_sched_wakeup(void *ignore, struct task_struct *wakee) |
57422797 | 31 | { |
dcef788e | 32 | if (unlikely(!sched_ref)) |
57422797 IM |
33 | return; |
34 | ||
b07c3f19 | 35 | tracing_record_cmdline(current); |
57422797 IM |
36 | } |
37 | ||
5b82a1b0 MD |
38 | static int tracing_sched_register(void) |
39 | { | |
40 | int ret; | |
41 | ||
38516ab5 | 42 | ret = register_trace_sched_wakeup(probe_sched_wakeup, NULL); |
5b82a1b0 | 43 | if (ret) { |
b07c3f19 | 44 | pr_info("wakeup trace: Couldn't activate tracepoint" |
5b82a1b0 MD |
45 | " probe to kernel_sched_wakeup\n"); |
46 | return ret; | |
47 | } | |
48 | ||
38516ab5 | 49 | ret = register_trace_sched_wakeup_new(probe_sched_wakeup, NULL); |
5b82a1b0 | 50 | if (ret) { |
b07c3f19 | 51 | pr_info("wakeup trace: Couldn't activate tracepoint" |
5b82a1b0 MD |
52 | " probe to kernel_sched_wakeup_new\n"); |
53 | goto fail_deprobe; | |
54 | } | |
55 | ||
38516ab5 | 56 | ret = register_trace_sched_switch(probe_sched_switch, NULL); |
5b82a1b0 | 57 | if (ret) { |
b07c3f19 | 58 | pr_info("sched trace: Couldn't activate tracepoint" |
73d8b8bc | 59 | " probe to kernel_sched_switch\n"); |
5b82a1b0 MD |
60 | goto fail_deprobe_wake_new; |
61 | } | |
62 | ||
63 | return ret; | |
64 | fail_deprobe_wake_new: | |
38516ab5 | 65 | unregister_trace_sched_wakeup_new(probe_sched_wakeup, NULL); |
5b82a1b0 | 66 | fail_deprobe: |
38516ab5 | 67 | unregister_trace_sched_wakeup(probe_sched_wakeup, NULL); |
5b82a1b0 MD |
68 | return ret; |
69 | } | |
70 | ||
71 | static void tracing_sched_unregister(void) | |
72 | { | |
38516ab5 SR |
73 | unregister_trace_sched_switch(probe_sched_switch, NULL); |
74 | unregister_trace_sched_wakeup_new(probe_sched_wakeup, NULL); | |
75 | unregister_trace_sched_wakeup(probe_sched_wakeup, NULL); | |
5b82a1b0 MD |
76 | } |
77 | ||
f2252935 | 78 | static void tracing_start_sched_switch(void) |
5b82a1b0 | 79 | { |
efade6e7 | 80 | mutex_lock(&sched_register_mutex); |
e168e051 | 81 | if (!(sched_ref++)) |
5b82a1b0 | 82 | tracing_sched_register(); |
efade6e7 | 83 | mutex_unlock(&sched_register_mutex); |
5b82a1b0 MD |
84 | } |
85 | ||
f2252935 | 86 | static void tracing_stop_sched_switch(void) |
5b82a1b0 | 87 | { |
efade6e7 | 88 | mutex_lock(&sched_register_mutex); |
e168e051 | 89 | if (!(--sched_ref)) |
5b82a1b0 | 90 | tracing_sched_unregister(); |
efade6e7 | 91 | mutex_unlock(&sched_register_mutex); |
5b82a1b0 MD |
92 | } |
93 | ||
41bc8144 SR |
94 | void tracing_start_cmdline_record(void) |
95 | { | |
96 | tracing_start_sched_switch(); | |
97 | } | |
98 | ||
99 | void tracing_stop_cmdline_record(void) | |
100 | { | |
101 | tracing_stop_sched_switch(); | |
102 | } |