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linux/samples/tracepoints/tracepoint-sample.c
Mathieu Desnoyers 7e066fb870 tracepoints: add DECLARE_TRACE() and DEFINE_TRACE()
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: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-16 09:01:36 +01:00

57 lines
1.2 KiB
C

/* 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");