diff options
author | Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> | 2007-10-19 02:41:08 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-19 14:53:55 -0400 |
commit | 31155bc03e35a8d2b2551bc2eea3da5791e1b776 (patch) | |
tree | 64a82cd692af1dc3672d311f5788e2dc6a56e546 /samples/markers/probe-example.c | |
parent | 267c4025f2e198a4e551556a6db31a554ca51814 (diff) |
Linux Kernel Markers - Samples
Module example showing how to use the Linux Kernel Markers.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'samples/markers/probe-example.c')
-rw-r--r-- | samples/markers/probe-example.c | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/samples/markers/probe-example.c b/samples/markers/probe-example.c new file mode 100644 index 000000000000..238b2e384fc8 --- /dev/null +++ b/samples/markers/probe-example.c | |||
@@ -0,0 +1,98 @@ | |||
1 | /* probe-example.c | ||
2 | * | ||
3 | * Connects 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 | struct probe_data { | ||
18 | const char *name; | ||
19 | const char *format; | ||
20 | marker_probe_func *probe_func; | ||
21 | }; | ||
22 | |||
23 | void probe_subsystem_event(const struct marker *mdata, void *private, | ||
24 | const char *format, ...) | ||
25 | { | ||
26 | va_list ap; | ||
27 | /* Declare args */ | ||
28 | unsigned int value; | ||
29 | const char *mystr; | ||
30 | |||
31 | /* Assign args */ | ||
32 | va_start(ap, format); | ||
33 | value = va_arg(ap, typeof(value)); | ||
34 | mystr = va_arg(ap, typeof(mystr)); | ||
35 | |||
36 | /* Call printk */ | ||
37 | printk(KERN_DEBUG "Value %u, string %s\n", value, mystr); | ||
38 | |||
39 | /* or count, check rights, serialize data in a buffer */ | ||
40 | |||
41 | va_end(ap); | ||
42 | } | ||
43 | |||
44 | atomic_t eventb_count = ATOMIC_INIT(0); | ||
45 | |||
46 | void probe_subsystem_eventb(const struct marker *mdata, void *private, | ||
47 | const char *format, ...) | ||
48 | { | ||
49 | /* Increment counter */ | ||
50 | atomic_inc(&eventb_count); | ||
51 | } | ||
52 | |||
53 | static struct probe_data probe_array[] = | ||
54 | { | ||
55 | { .name = "subsystem_event", | ||
56 | .format = "%d %s", | ||
57 | .probe_func = probe_subsystem_event }, | ||
58 | { .name = "subsystem_eventb", | ||
59 | .format = MARK_NOARGS, | ||
60 | .probe_func = probe_subsystem_eventb }, | ||
61 | }; | ||
62 | |||
63 | static int __init probe_init(void) | ||
64 | { | ||
65 | int result; | ||
66 | int i; | ||
67 | |||
68 | for (i = 0; i < ARRAY_SIZE(probe_array); i++) { | ||
69 | result = marker_probe_register(probe_array[i].name, | ||
70 | probe_array[i].format, | ||
71 | probe_array[i].probe_func, &probe_array[i]); | ||
72 | if (result) | ||
73 | printk(KERN_INFO "Unable to register probe %s\n", | ||
74 | probe_array[i].name); | ||
75 | result = marker_arm(probe_array[i].name); | ||
76 | if (result) | ||
77 | printk(KERN_INFO "Unable to arm probe %s\n", | ||
78 | probe_array[i].name); | ||
79 | } | ||
80 | return 0; | ||
81 | } | ||
82 | |||
83 | static void __exit probe_fini(void) | ||
84 | { | ||
85 | int i; | ||
86 | |||
87 | for (i = 0; i < ARRAY_SIZE(probe_array); i++) | ||
88 | marker_probe_unregister(probe_array[i].name); | ||
89 | printk(KERN_INFO "Number of event b : %u\n", | ||
90 | atomic_read(&eventb_count)); | ||
91 | } | ||
92 | |||
93 | module_init(probe_init); | ||
94 | module_exit(probe_fini); | ||
95 | |||
96 | MODULE_LICENSE("GPL"); | ||
97 | MODULE_AUTHOR("Mathieu Desnoyers"); | ||
98 | MODULE_DESCRIPTION("SUBSYSTEM Probe"); | ||