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authorLi Zefan <lizf@cn.fujitsu.com>2009-08-17 16:56:28 +0800
committerIngo Molnar <mingo@elte.hu>2009-08-17 11:25:08 +0200
commit7ead8b8313d92b3a69a1a61b0dcbc4cd66c960dc (patch)
tree614759ec1b24ea9f6d1409b866c80df0611e5d6b /kernel/module.c
parent60d970c254b95ec7a0fc4c590b510253987b64a0 (diff)
downloadlinux-7ead8b8313d92b3a69a1a61b0dcbc4cd66c960dc.tar.bz2
tracing/events: Add module tracepoints
Add trace points to trace module_load, module_free, module_get, module_put and module_request, and use trace_event facility to get the trace output. Here's the sample output: TASK-PID CPU# TIMESTAMP FUNCTION | | | | | <...>-42 [000] 1.758380: module_request: fb0 wait=1 call_site=fb_open ... <...>-60 [000] 3.269403: module_load: scsi_wait_scan <...>-60 [000] 3.269432: module_put: scsi_wait_scan call_site=sys_init_module refcnt=0 <...>-61 [001] 3.273168: module_free: scsi_wait_scan ... <...>-1021 [000] 13.836081: module_load: sunrpc <...>-1021 [000] 13.840589: module_put: sunrpc call_site=sys_init_module refcnt=-1 <...>-1027 [000] 13.848098: module_get: sunrpc call_site=try_module_get refcnt=0 <...>-1027 [000] 13.848308: module_get: sunrpc call_site=get_filesystem refcnt=1 <...>-1027 [000] 13.848692: module_put: sunrpc call_site=put_filesystem refcnt=0 ... modprobe-2587 [001] 1088.437213: module_load: trace_events_sample F modprobe-2587 [001] 1088.437786: module_put: trace_events_sample call_site=sys_init_module refcnt=0 Note: - the taints flag can be 'F', 'C' and/or 'P' if mod->taints != 0 - the module refcnt is percpu, so it can be negative in a specific cpu Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Rusty Russell <rusty@rustcorp.com.au> LKML-Reference: <4A891B3C.5030608@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/module.c')
-rw-r--r--kernel/module.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/kernel/module.c b/kernel/module.c
index fd1411403558..b1821438694e 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -55,6 +55,11 @@
#include <linux/percpu.h>
#include <linux/kmemleak.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/module.h>
+
+EXPORT_TRACEPOINT_SYMBOL(module_get);
+
#if 0
#define DEBUGP printk
#else
@@ -940,6 +945,8 @@ void module_put(struct module *module)
if (module) {
unsigned int cpu = get_cpu();
local_dec(__module_ref_addr(module, cpu));
+ trace_module_put(module, _RET_IP_,
+ local_read(__module_ref_addr(module, cpu)));
/* Maybe they're waiting for us to drop reference? */
if (unlikely(!module_is_live(module)))
wake_up_process(module->waiter);
@@ -1491,6 +1498,8 @@ static int __unlink_module(void *_mod)
/* Free a module, remove from lists, etc (must hold module_mutex). */
static void free_module(struct module *mod)
{
+ trace_module_free(mod);
+
/* Delete from various lists */
stop_machine(__unlink_module, mod, NULL);
remove_notes_attrs(mod);
@@ -2358,6 +2367,8 @@ static noinline struct module *load_module(void __user *umod,
/* Get rid of temporary copy */
vfree(hdr);
+ trace_module_load(mod);
+
/* Done! */
return mod;