1 // SPDX-License-Identifier: GPL-2.0
5 * Copyright (C) 2007 Steven Rostedt <srostedt@redhat.com>
8 #include <linux/module.h>
9 #include <linux/kallsyms.h>
10 #include <linux/uaccess.h>
11 #include <linux/ftrace.h>
12 #include <trace/events/sched.h>
16 #define RECORD_CMDLINE 1
19 static int sched_cmdline_ref;
20 static int sched_tgid_ref;
21 static DEFINE_MUTEX(sched_register_mutex);
24 probe_sched_switch(void *ignore, bool preempt,
25 unsigned int prev_state,
26 struct task_struct *prev, struct task_struct *next)
30 flags = (RECORD_TGID * !!sched_tgid_ref) +
31 (RECORD_CMDLINE * !!sched_cmdline_ref);
35 tracing_record_taskinfo_sched_switch(prev, next, flags);
39 probe_sched_wakeup(void *ignore, struct task_struct *wakee)
43 flags = (RECORD_TGID * !!sched_tgid_ref) +
44 (RECORD_CMDLINE * !!sched_cmdline_ref);
48 tracing_record_taskinfo(current, flags);
51 static int tracing_sched_register(void)
55 ret = register_trace_sched_wakeup(probe_sched_wakeup, NULL);
57 pr_info("wakeup trace: Couldn't activate tracepoint"
58 " probe to kernel_sched_wakeup\n");
62 ret = register_trace_sched_wakeup_new(probe_sched_wakeup, NULL);
64 pr_info("wakeup trace: Couldn't activate tracepoint"
65 " probe to kernel_sched_wakeup_new\n");
69 ret = register_trace_sched_switch(probe_sched_switch, NULL);
71 pr_info("sched trace: Couldn't activate tracepoint"
72 " probe to kernel_sched_switch\n");
73 goto fail_deprobe_wake_new;
77 fail_deprobe_wake_new:
78 unregister_trace_sched_wakeup_new(probe_sched_wakeup, NULL);
80 unregister_trace_sched_wakeup(probe_sched_wakeup, NULL);
84 static void tracing_sched_unregister(void)
86 unregister_trace_sched_switch(probe_sched_switch, NULL);
87 unregister_trace_sched_wakeup_new(probe_sched_wakeup, NULL);
88 unregister_trace_sched_wakeup(probe_sched_wakeup, NULL);
91 static void tracing_start_sched_switch(int ops)
95 mutex_lock(&sched_register_mutex);
96 sched_register = (!sched_cmdline_ref && !sched_tgid_ref);
108 if (sched_register && (sched_cmdline_ref || sched_tgid_ref))
109 tracing_sched_register();
110 mutex_unlock(&sched_register_mutex);
113 static void tracing_stop_sched_switch(int ops)
115 mutex_lock(&sched_register_mutex);
127 if (!sched_cmdline_ref && !sched_tgid_ref)
128 tracing_sched_unregister();
129 mutex_unlock(&sched_register_mutex);
132 void tracing_start_cmdline_record(void)
134 tracing_start_sched_switch(RECORD_CMDLINE);
137 void tracing_stop_cmdline_record(void)
139 tracing_stop_sched_switch(RECORD_CMDLINE);
142 void tracing_start_tgid_record(void)
144 tracing_start_sched_switch(RECORD_TGID);
147 void tracing_stop_tgid_record(void)
149 tracing_stop_sched_switch(RECORD_TGID);