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 X-Spam-Level: X-Spam-Status: No, score=-11.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,HK_RANDOM_FROM,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 50DDCC4708E for ; Sat, 29 May 2021 05:47:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1ECB16113B for ; Sat, 29 May 2021 05:47:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229640AbhE2FtL (ORCPT ); Sat, 29 May 2021 01:49:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36616 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229560AbhE2FtJ (ORCPT ); Sat, 29 May 2021 01:49:09 -0400 Received: from mail-pl1-x62c.google.com (mail-pl1-x62c.google.com [IPv6:2607:f8b0:4864:20::62c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D4B5AC061574 for ; Fri, 28 May 2021 22:47:31 -0700 (PDT) Received: by mail-pl1-x62c.google.com with SMTP id v12so2606488plo.10 for ; Fri, 28 May 2021 22:47:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=+6wfairYo2CV28udtUyOfuk12wN9dfgkVcgLBZf4u1Q=; b=bp0r4ZR71lSmk7v/awWwkU8KPkovHiIXtln5DoWV/tTXOdfzqIS+MI4amQGOlUG5sV Byfa2F0kXUitG1BEYJkHdjZZTtuY8AnV5Lp5hfekK3rx8VHb7GpVV90BH/gYV9QE89FH +1/FOZ4/SFk4DGuITBRhnG9H0l7Icw9NO6i+n5A01BNEH4OY6RyzEjXtRLinsLYs8HOw waW3/pFzDDYU2AGmHeocCXzSr5UA63OROFLId3/bhby+F22BKoR18G6zvGqyspU3/v/n gjfufPkpfD4UfWlcTxxiUlURZzgTieGoD6BME7FynCuu6isQO/qfkkh16cJ0arty4zuV Dzkg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=+6wfairYo2CV28udtUyOfuk12wN9dfgkVcgLBZf4u1Q=; b=i57pv1YZFswAY4qraBPvyqrfPlrFCBmsekGVwEg8FpUpz/3UWT0ETB4IrI80TlYYpC fP7/ZVoPWBqt05IzT7cvl0s8WyWVTZ9Du6/2F9DLSr6NR+4HTZolKl6Y2tr4qU+1aUDC MBnzTI1s8NLlF7QgspK1zYT7SjtW9a7NuCSO1S+wn3LwT7eKdPatuLQl6u9ozBkxlpoD deEpVK8/SwTn31946+emj24CSDmz3482wEAf0xpzvJm2WKZevZEgLOS1n9IAloZqdCe+ WstGsSdhn7GMYmaL02IvG4roGDWNgHhnsiowdK09Lck0dlM37rGxB/55X5j1LdWrSLYO wZQw== X-Gm-Message-State: AOAM532MPvgVqTqcfVGkVyBfmVF2zUDCY+y8AY+zPbHdzkBKDZJAz82l 1V/0I/tknp+Wi7KRlK5g1FrtVtTenp5v+Q== X-Google-Smtp-Source: ABdhPJx2deDrGnaHDeEYA9kYbXGp9rxsKX+GPPB4bdr+M5IHtpT4J/szzfJbjMMd2lFSPnKyFScDdQ== X-Received: by 2002:a17:90b:4a4a:: with SMTP id lb10mr8135623pjb.21.1622267251332; Fri, 28 May 2021 22:47:31 -0700 (PDT) Received: from hyeyoo ([183.99.11.150]) by smtp.gmail.com with ESMTPSA id z5sm4167126pfb.114.2021.05.28.22.47.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 28 May 2021 22:47:31 -0700 (PDT) Date: Sat, 29 May 2021 14:47:25 +0900 From: Hyeonggon Yoo <42.hyeyoo@gmail.com> To: Steven Rostedt Cc: Ingo Molnar , linux-kernel@vger.kernel.org, Tom Zanussi Subject: Re: [PATCH] tracing: Remove redundant variable ret Message-ID: <20210529054725.GA99161@hyeyoo> References: <20210527171449.GA145584@hyeyoo> <20210528222257.7c5cb8b9@oasis.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210528222257.7c5cb8b9@oasis.local.home> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 28, 2021 at 10:22:57PM -0400, Steven Rostedt wrote: > On Fri, 28 May 2021 02:14:49 +0900 > Hyeonggon Yoo <42.hyeyoo@gmail.com> wrote: > > > This variable saves return value of event_hist_trigger_func, > > but it's never read. So it's redundant. > > > > Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> > > --- > > kernel/trace/trace_events_hist.c | 3 +-- > > 1 file changed, 1 insertion(+), 2 deletions(-) > > > > diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c > > index c1abd63f1d6c..414f2727d7a7 100644 > > --- a/kernel/trace/trace_events_hist.c > > +++ b/kernel/trace/trace_events_hist.c > > @@ -5225,12 +5225,11 @@ static void unregister_field_var_hists(struct hist_trigger_data *hist_data) > > struct trace_event_file *file; > > unsigned int i; > > char *cmd; > > - int ret; > > > > for (i = 0; i < hist_data->n_field_var_hists; i++) { > > file = hist_data->field_var_hists[i]->hist_data->event_file; > > cmd = hist_data->field_var_hists[i]->cmd; > > - ret = event_hist_trigger_func(&trigger_hist_cmd, file, > > + event_hist_trigger_func(&trigger_hist_cmd, file, > > "!hist", "hist", cmd); > > I wonder if instead we should add: > > WARN_ON_ONCE(ret < 0); > Oh, Seems better to warn, not ignoring.