Commit 51714678 authored by Zhen Lei's avatar Zhen Lei Committed by Steven Rostedt (Google)
Browse files

tracepoint: Optimize the critical region of mutex_lock in tracepoint_module_coming() 

The memory allocation of 'tp_mod' does not require mutex_lock()
protection, move it out.

Link: https://lkml.kernel.org/r/20220914061416.1630-1-thunder.leizhen@huawei.com



Signed-off-by: default avatarZhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent fde59ab1

kernel/tracepoint.c

+6 −8
Original line number Diff line number Diff line
@@ -640,7 +640,6 @@ static void tp_module_going_check_quiescent(struct tracepoint *tp, void *priv) 
static int tracepoint_module_coming(struct module *mod)

{

	struct tp_module *tp_mod;

	int ret = 0;



	if (!mod->num_tracepoints)

		return 0;
@@ -652,19 +651,18 @@ static int tracepoint_module_coming(struct module *mod) 
	 */

	if (trace_module_has_bad_taint(mod))

		return 0;

	mutex_lock(&tracepoint_module_list_mutex);



	tp_mod = kmalloc(sizeof(struct tp_module), GFP_KERNEL);

	if (!tp_mod) {

		ret = -ENOMEM;

		goto end;

	}

	if (!tp_mod)

		return -ENOMEM;

	tp_mod->mod = mod;



	mutex_lock(&tracepoint_module_list_mutex);

	list_add_tail(&tp_mod->list, &tracepoint_module_list);

	blocking_notifier_call_chain(&tracepoint_notify_list,

			MODULE_STATE_COMING, tp_mod);

end:

	mutex_unlock(&tracepoint_module_list_mutex);

	return ret;

	return 0;

}



static void tracepoint_module_going(struct module *mod)