[lttv.git] / tests / kernel / probe-example.c

/* probe-example.c
 *
 * Connects a two functions to marker call sites.
 *
 * (C) Copyright 2007 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
 *
 * This file is released under the GPLv2.
 * See the file COPYING for more details.
 */

#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/marker.h>
#include <asm/atomic.h>

#define NUM_PROBES (sizeof(probe_array) / sizeof(struct probe_data))

struct probe_data {
	const char *name;
	const char *format;
	marker_probe_func *probe_func;
};

void probe_subsystem_event(const struct __mark_marker_c *mdata,
		const char *format, ...)
{
	va_list ap;
	/* Declare args */
	unsigned int value;
	const char *mystr;

	/* Assign args */
	va_start(ap, format);
	value = va_arg(ap, typeof(value));
	mystr = va_arg(ap, typeof(mystr));

	/* Call printk */
	printk("Value %u, string %s\n", value, mystr);

	/* or count, check rights, serialize data in a buffer */

	va_end(ap);
}

atomic_t eventb_count = ATOMIC_INIT(0);

void probe_subsystem_eventb(const struct __mark_marker_c *mdata,
	const char *format, ...)
{
	/* Increment counter */
	atomic_inc(&eventb_count);
}

static struct probe_data probe_array[] =
{
	{	.name = "subsystem_event",
		.format = "%d %s",
		.probe_func = probe_subsystem_event },
	{	.name = "subsystem_eventb",
		.format = MARK_NOARGS,
		.probe_func = probe_subsystem_eventb },
};

static int __init probe_init(void)
{
	int result;
	uint8_t eID;

	for (eID = 0; eID < NUM_PROBES; eID++) {
		result = marker_set_probe(probe_array[eID].name,
				probe_array[eID].format,
				probe_array[eID].probe_func, &probe_array[eID]);
		if (!result)
			printk(KERN_INFO "Unable to register probe %s\n",
				probe_array[eID].name);
	}
	return 0;
}

static void __exit probe_fini(void)
{
	uint8_t eID;

	for (eID = 0; eID < NUM_PROBES; eID++) {
		marker_remove_probe(probe_array[eID].name);
	}
	synchronize_sched();	/* Wait for probes to finish */
	printk("Number of event b : %u\n", atomic_read(&eventb_count));
}

module_init(probe_init);
module_exit(probe_fini);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Mathieu Desnoyers");
MODULE_DESCRIPTION("SUBSYSTEM Probe");
Commit	Line	Data
d06fc4d5	1	/* probe-example.c
	2	*
	3	* Connects a two functions to marker call sites.
	4	*
	5	* (C) Copyright 2007 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
	6	*
	7	* This file is released under the GPLv2.
	8	* See the file COPYING for more details.
	9	*/
	10
	11	#include <linux/sched.h>
	12	#include <linux/kernel.h>
	13	#include <linux/module.h>
	14	#include <linux/marker.h>
	15	#include <asm/atomic.h>
	16
	17	#define NUM_PROBES (sizeof(probe_array) / sizeof(struct probe_data))
	18
	19	struct probe_data {
	20	const char *name;
	21	const char *format;
	22	marker_probe_func *probe_func;
	23	};
	24
	25	void probe_subsystem_event(const struct __mark_marker_c *mdata,
	26	const char *format, ...)
	27	{
	28	va_list ap;
	29	/* Declare args */
	30	unsigned int value;
	31	const char *mystr;
d06fc4d5	32
	33	/* Assign args */
	34	va_start(ap, format);
	35	value = va_arg(ap, typeof(value));
	36	mystr = va_arg(ap, typeof(mystr));
d06fc4d5	37
d06fc4d5	38	/* Call printk */
421991b0	39	printk("Value %u, string %s\n", value, mystr);
d06fc4d5	40
	41	/* or count, check rights, serialize data in a buffer */
	42
	43	va_end(ap);
	44	}
	45
	46	atomic_t eventb_count = ATOMIC_INIT(0);
	47
	48	void probe_subsystem_eventb(const struct __mark_marker_c *mdata,
	49	const char *format, ...)
	50	{
	51	/* Increment counter */
	52	atomic_inc(&eventb_count);
	53	}
	54
	55	static struct probe_data probe_array[] =
	56	{
	57	{ .name = "subsystem_event",
421991b0	58	.format = "%d %s",
d06fc4d5	59	.probe_func = probe_subsystem_event },
	60	{ .name = "subsystem_eventb",
	61	.format = MARK_NOARGS,
	62	.probe_func = probe_subsystem_eventb },
	63	};
	64
	65	static int __init probe_init(void)
	66	{
	67	int result;
	68	uint8_t eID;
	69
	70	for (eID = 0; eID < NUM_PROBES; eID++) {
	71	result = marker_set_probe(probe_array[eID].name,
	72	probe_array[eID].format,
	73	probe_array[eID].probe_func, &probe_array[eID]);
	74	if (!result)
	75	printk(KERN_INFO "Unable to register probe %s\n",
	76	probe_array[eID].name);
	77	}
	78	return 0;
	79	}
	80
	81	static void __exit probe_fini(void)
	82	{
	83	uint8_t eID;
	84
	85	for (eID = 0; eID < NUM_PROBES; eID++) {
	86	marker_remove_probe(probe_array[eID].name);
	87	}
	88	synchronize_sched(); /* Wait for probes to finish */
	89	printk("Number of event b : %u\n", atomic_read(&eventb_count));
	90	}
	91
	92	module_init(probe_init);
	93	module_exit(probe_fini);
	94
	95	MODULE_LICENSE("GPL");
	96	MODULE_AUTHOR("Mathieu Desnoyers");
	97	MODULE_DESCRIPTION("SUBSYSTEM Probe");