• Mathieu Desnoyers's avatar
    tracepoints: add DECLARE_TRACE() and DEFINE_TRACE() · 7e066fb8
    Mathieu Desnoyers authored
    
    Impact: API *CHANGE*. Must update all tracepoint users.
    
    Add DEFINE_TRACE() to tracepoints to let them declare the tracepoint
    structure in a single spot for all the kernel. It helps reducing memory
    consumption, especially when declaring a lot of tracepoints, e.g. for
    kmalloc tracing.
    
    *API CHANGE WARNING*: now, DECLARE_TRACE() must be used in headers for
    tracepoint declarations rather than DEFINE_TRACE(). This is the sane way
    to do it. The name previously used was misleading.
    
    Updates scheduler instrumentation to follow this API change.
    Signed-off-by: default avatarMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
    Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
    7e066fb8
tracepoint-sample.c 1.15 KB
/* tracepoint-sample.c
 *
 * Executes a tracepoint when /proc/tracepoint-example is opened.
 *
 * (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/module.h>
#include <linux/sched.h>
#include <linux/proc_fs.h>
#include "tp-samples-trace.h"

DEFINE_TRACE(subsys_event);
DEFINE_TRACE(subsys_eventb);

struct proc_dir_entry *pentry_example;

static int my_open(struct inode *inode, struct file *file)
{
	int i;

	trace_subsys_event(inode, file);
	for (i = 0; i < 10; i++)
		trace_subsys_eventb();
	return -EPERM;
}

static struct file_operations mark_ops = {
	.open = my_open,
};

static int example_init(void)
{
	printk(KERN_ALERT "example init\n");
	pentry_example = proc_create("tracepoint-example", 0444, NULL,
		&mark_ops);
	if (!pentry_example)
		return -EPERM;
	return 0;
}

static void example_exit(void)
{
	printk(KERN_ALERT "example exit\n");
	remove_proc_entry("tracepoint-example", NULL);
}

module_init(example_init)
module_exit(example_exit)

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Mathieu Desnoyers");
MODULE_DESCRIPTION("Tracepoint example");