From 51714678eacc91fcfb8b235ced57ea70ade81cad Mon Sep 17 00:00:00 2001 From: Zhen Lei Date: Wed, 14 Sep 2022 14:14:16 +0800 Subject: [PATCH] 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: Zhen Lei Signed-off-by: Steven Rostedt (Google) --- kernel/tracepoint.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c index ef42c1a11920..f23144af5743 100644 --- a/kernel/tracepoint.c +++ b/kernel/tracepoint.c @@ -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)