[linux-2.6-block.git] / kernel / trace / trace_sched_switch.c

/*
 * trace context switch
 *
 * Copyright (C) 2007 Steven Rostedt <srostedt@redhat.com>
 *
 */
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/uaccess.h>
#include <linux/ftrace.h>
#include <trace/events/sched.h>

#include "trace.h"

#define RECORD_CMDLINE	1
#define RECORD_TGID	2

static int		sched_cmdline_ref;
static int		sched_tgid_ref;
static DEFINE_MUTEX(sched_register_mutex);

static void
probe_sched_switch(void *ignore, bool preempt,
		   struct task_struct *prev, struct task_struct *next)
{
	int flags;

	flags = (RECORD_TGID * !!sched_tgid_ref) +
		(RECORD_CMDLINE * !!sched_cmdline_ref);

	if (!flags)
		return;
	tracing_record_taskinfo_sched_switch(prev, next, flags);
}

static void
probe_sched_wakeup(void *ignore, struct task_struct *wakee)
{
	int flags;

	flags = (RECORD_TGID * !!sched_tgid_ref) +
		(RECORD_CMDLINE * !!sched_cmdline_ref);

	if (!flags)
		return;
	tracing_record_taskinfo(current, flags);
}

static int tracing_sched_register(void)
{
	int ret;

	ret = register_trace_sched_wakeup(probe_sched_wakeup, NULL);
	if (ret) {
		pr_info("wakeup trace: Couldn't activate tracepoint"
			" probe to kernel_sched_wakeup\n");
		return ret;
	}

	ret = register_trace_sched_wakeup_new(probe_sched_wakeup, NULL);
	if (ret) {
		pr_info("wakeup trace: Couldn't activate tracepoint"
			" probe to kernel_sched_wakeup_new\n");
		goto fail_deprobe;
	}

	ret = register_trace_sched_switch(probe_sched_switch, NULL);
	if (ret) {
		pr_info("sched trace: Couldn't activate tracepoint"
			" probe to kernel_sched_switch\n");
		goto fail_deprobe_wake_new;
	}

	return ret;
fail_deprobe_wake_new:
	unregister_trace_sched_wakeup_new(probe_sched_wakeup, NULL);
fail_deprobe:
	unregister_trace_sched_wakeup(probe_sched_wakeup, NULL);
	return ret;
}

static void tracing_sched_unregister(void)
{
	unregister_trace_sched_switch(probe_sched_switch, NULL);
	unregister_trace_sched_wakeup_new(probe_sched_wakeup, NULL);
	unregister_trace_sched_wakeup(probe_sched_wakeup, NULL);
}

static void tracing_start_sched_switch(int ops)
{
	bool sched_register = (!sched_cmdline_ref && !sched_tgid_ref);
	mutex_lock(&sched_register_mutex);

	switch (ops) {
	case RECORD_CMDLINE:
		sched_cmdline_ref++;
		break;

	case RECORD_TGID:
		sched_tgid_ref++;
		break;
	}

	if (sched_register && (sched_cmdline_ref || sched_tgid_ref))
		tracing_sched_register();
	mutex_unlock(&sched_register_mutex);
}

static void tracing_stop_sched_switch(int ops)
{
	mutex_lock(&sched_register_mutex);

	switch (ops) {
	case RECORD_CMDLINE:
		sched_cmdline_ref--;
		break;

	case RECORD_TGID:
		sched_tgid_ref--;
		break;
	}

	if (!sched_cmdline_ref && !sched_tgid_ref)
		tracing_sched_unregister();
	mutex_unlock(&sched_register_mutex);
}

void tracing_start_cmdline_record(void)
{
	tracing_start_sched_switch(RECORD_CMDLINE);
}

void tracing_stop_cmdline_record(void)
{
	tracing_stop_sched_switch(RECORD_CMDLINE);
}

void tracing_start_tgid_record(void)
{
	tracing_start_sched_switch(RECORD_TGID);
}

void tracing_stop_tgid_record(void)
{
	tracing_stop_sched_switch(RECORD_TGID);
}
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>
35e8e302 SR	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
d914ba37 JF	15	#define RECORD_CMDLINE 1
	16	#define RECORD_TGID 2
	17
	18	static int sched_cmdline_ref;
	19	static int sched_tgid_ref;
efade6e7	20	static DEFINE_MUTEX(sched_register_mutex);
82e04af4	21
e309b41d	22	static void
c73464b1 PZ	23	probe_sched_switch(void *ignore, bool preempt,
c73464b1 PZ	24	struct task_struct prev, struct task_struct next)
35e8e302	25	{
d914ba37 JF	26	int flags;
	27
	28	flags = (RECORD_TGID * !!sched_tgid_ref) +
	29	(RECORD_CMDLINE * !!sched_cmdline_ref);
b07c3f19	30
d914ba37 JF	31	if (!flags)
	32	return;
	33	tracing_record_taskinfo_sched_switch(prev, next, flags);
35e8e302 SR	34	}
35e8e302 SR	35
4e655519	36	static void
fbd705a0	37	probe_sched_wakeup(void ignore, struct task_struct wakee)
57422797	38	{
d914ba37 JF	39	int flags;
	40
	41	flags = (RECORD_TGID * !!sched_tgid_ref) +
	42	(RECORD_CMDLINE * !!sched_cmdline_ref);
57422797	43
d914ba37 JF	44	if (!flags)
	45	return;
	46	tracing_record_taskinfo(current, flags);
57422797 IM	47	}
57422797 IM	48
5b82a1b0 MD	49	static int tracing_sched_register(void)
	50	{
	51	int ret;
	52
38516ab5	53	ret = register_trace_sched_wakeup(probe_sched_wakeup, NULL);
5b82a1b0	54	if (ret) {
b07c3f19	55	pr_info("wakeup trace: Couldn't activate tracepoint"
5b82a1b0 MD	56	" probe to kernel_sched_wakeup\n");
	57	return ret;
	58	}
	59
38516ab5	60	ret = register_trace_sched_wakeup_new(probe_sched_wakeup, NULL);
5b82a1b0	61	if (ret) {
b07c3f19	62	pr_info("wakeup trace: Couldn't activate tracepoint"
5b82a1b0 MD	63	" probe to kernel_sched_wakeup_new\n");
	64	goto fail_deprobe;
	65	}
	66
38516ab5	67	ret = register_trace_sched_switch(probe_sched_switch, NULL);
5b82a1b0	68	if (ret) {
b07c3f19	69	pr_info("sched trace: Couldn't activate tracepoint"
73d8b8bc	70	" probe to kernel_sched_switch\n");
5b82a1b0 MD	71	goto fail_deprobe_wake_new;
	72	}
	73
	74	return ret;
	75	fail_deprobe_wake_new:
38516ab5	76	unregister_trace_sched_wakeup_new(probe_sched_wakeup, NULL);
5b82a1b0	77	fail_deprobe:
38516ab5	78	unregister_trace_sched_wakeup(probe_sched_wakeup, NULL);
5b82a1b0 MD	79	return ret;
	80	}
	81
	82	static void tracing_sched_unregister(void)
	83	{
38516ab5 SR	84	unregister_trace_sched_switch(probe_sched_switch, NULL);
	85	unregister_trace_sched_wakeup_new(probe_sched_wakeup, NULL);
	86	unregister_trace_sched_wakeup(probe_sched_wakeup, NULL);
5b82a1b0 MD	87	}
5b82a1b0 MD	88
d914ba37	89	static void tracing_start_sched_switch(int ops)
5b82a1b0	90	{
d914ba37	91	bool sched_register = (!sched_cmdline_ref && !sched_tgid_ref);
efade6e7	92	mutex_lock(&sched_register_mutex);
d914ba37 JF	93
	94	switch (ops) {
	95	case RECORD_CMDLINE:
	96	sched_cmdline_ref++;
	97	break;
	98
	99	case RECORD_TGID:
	100	sched_tgid_ref++;
	101	break;
	102	}
	103
	104	if (sched_register && (sched_cmdline_ref \|\| sched_tgid_ref))
5b82a1b0	105	tracing_sched_register();
efade6e7	106	mutex_unlock(&sched_register_mutex);
5b82a1b0 MD	107	}
5b82a1b0 MD	108
d914ba37	109	static void tracing_stop_sched_switch(int ops)
5b82a1b0	110	{
efade6e7	111	mutex_lock(&sched_register_mutex);
d914ba37 JF	112
	113	switch (ops) {
	114	case RECORD_CMDLINE:
	115	sched_cmdline_ref--;
	116	break;
	117
	118	case RECORD_TGID:
	119	sched_tgid_ref--;
	120	break;
	121	}
	122
	123	if (!sched_cmdline_ref && !sched_tgid_ref)
5b82a1b0	124	tracing_sched_unregister();
efade6e7	125	mutex_unlock(&sched_register_mutex);
5b82a1b0 MD	126	}
5b82a1b0 MD	127
41bc8144 SR	128	void tracing_start_cmdline_record(void)
41bc8144 SR	129	{
d914ba37	130	tracing_start_sched_switch(RECORD_CMDLINE);
41bc8144 SR	131	}
	132
	133	void tracing_stop_cmdline_record(void)
	134	{
d914ba37 JF	135	tracing_stop_sched_switch(RECORD_CMDLINE);
	136	}
	137
	138	void tracing_start_tgid_record(void)
	139	{
	140	tracing_start_sched_switch(RECORD_TGID);
	141	}
	142
	143	void tracing_stop_tgid_record(void)
	144	{
	145	tracing_stop_sched_switch(RECORD_TGID);
41bc8144	146	}