From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0F45FC4332F for ; Tue, 20 Dec 2022 01:47:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233050AbiLTBrK (ORCPT ); Mon, 19 Dec 2022 20:47:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46288 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232762AbiLTBqj (ORCPT ); Mon, 19 Dec 2022 20:46:39 -0500 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0E01F12AEA; Mon, 19 Dec 2022 17:40:08 -0800 (PST) Received: from dggpeml100012.china.huawei.com (unknown [172.30.72.54]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4NbfPH67TJzmWgw; Tue, 20 Dec 2022 09:38:59 +0800 (CST) Received: from [10.67.110.218] (10.67.110.218) by dggpeml100012.china.huawei.com (7.185.36.121) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.34; Tue, 20 Dec 2022 09:40:05 +0800 Message-ID: Date: Tue, 20 Dec 2022 09:40:05 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.6.0 Subject: Re: [PATCH] tracing: Add a way to filter function addresses to function names Content-Language: en-US To: Steven Rostedt CC: LKML , Linux Trace Kernel , Masami Hiramatsu , Andrew Morton , Ross Zwisler , Tom Zanussi References: <20221214125209.09d736dd@gandalf.local.home> <68fa6a9d-7a7f-00ba-e5a2-9b64f0aa7db3@huawei.com> <20221219132102.0dc6b7b9@gandalf.local.home> From: Zheng Yejian In-Reply-To: <20221219132102.0dc6b7b9@gandalf.local.home> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.67.110.218] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To dggpeml100012.china.huawei.com (7.185.36.121) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022/12/20 02:21, Steven Rostedt wrote: > On Mon, 19 Dec 2022 10:38:50 +0800 > Zheng Yejian wrote: > >>> diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c >>> index 33e0b4f8ebe6..db6e2f399440 100644 >>> --- a/kernel/trace/trace_events.c >>> +++ b/kernel/trace/trace_events.c >>> @@ -2822,7 +2822,7 @@ static __init int setup_trace_triggers(char *str) >>> if (!trigger) >>> break; >>> bootup_triggers[i].event = strsep(&trigger, "."); >>> - bootup_triggers[i].trigger = strsep(&trigger, "."); >>> + bootup_triggers[i].trigger = strsep(&trigger, ""); >> >> Would it be better to change to: >> >> bootup_triggers[i].trigger = trigger; >> > > Sure, I'll make the update. > >> Because there is unnecessary loop if call strsep(s, "") :-) >> strsep(s, ct) { >> strpbrk(cs, ct) { >> // when 'ct' is empty string, here will always return NULL >> // after traversing string 'cs' > > I'm not sure what you mean about an extra loop. I just mean above "traversing string 'cs'" in strpbrk(s, "") is unnecessary. Sorry for making the ambiguity :-( > > Thanks, > > -- Steve >