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>
diff --git a/include/linux/module.h b/include/linux/module.h
index 098bdb7..f8f92d0 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -17,10 +17,12 @@
#include <linux/moduleparam.h>
#include <linux/marker.h>
#include <linux/tracepoint.h>
-#include <asm/local.h>
+#include <asm/local.h>
#include <asm/module.h>
+#include <trace/events/module.h>
+
/* Not Yet Implemented */
#define MODULE_SUPPORTED_DEVICE(name)
@@ -462,7 +464,10 @@
static inline void __module_get(struct module *module)
{
if (module) {
- local_inc(__module_ref_addr(module, get_cpu()));
+ unsigned int cpu = get_cpu();
+ local_inc(__module_ref_addr(module, cpu));
+ trace_module_get(module, _THIS_IP_,
+ local_read(__module_ref_addr(module, cpu)));
put_cpu();
}
}
@@ -473,8 +478,11 @@
if (module) {
unsigned int cpu = get_cpu();
- if (likely(module_is_live(module)))
+ if (likely(module_is_live(module))) {
local_inc(__module_ref_addr(module, cpu));
+ trace_module_get(module, _THIS_IP_,
+ local_read(__module_ref_addr(module, cpu)));
+ }
else
ret = 0;
put_cpu();