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=-13.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 6C0DBC433E1 for ; Thu, 27 Aug 2020 06:41:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 47FCD22B47 for ; Thu, 27 Aug 2020 06:41:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727031AbgH0Glf (ORCPT ); Thu, 27 Aug 2020 02:41:35 -0400 Received: from szxga07-in.huawei.com ([45.249.212.35]:33438 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726242AbgH0Gle (ORCPT ); Thu, 27 Aug 2020 02:41:34 -0400 Received: from DGGEMS401-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 66EA699BB0E985A9E51E; Thu, 27 Aug 2020 14:41:32 +0800 (CST) Received: from [127.0.0.1] (10.174.177.253) by DGGEMS401-HUB.china.huawei.com (10.3.19.201) with Microsoft SMTP Server id 14.3.487.0; Thu, 27 Aug 2020 14:41:28 +0800 Subject: Re: [PATCH 3/4] libnvdimm: eliminate two unnecessary zero initializations in badrange.c To: Oliver O'Halloran , Dan Williams , Vishal Verma , "Dave Jiang" , Ira Weiny , linux-nvdimm , linux-kernel References: <20200820143027.3241-1-thunder.leizhen@huawei.com> <20200820143027.3241-4-thunder.leizhen@huawei.com> From: "Leizhen (ThunderTown)" Message-ID: <962dd111-ceb3-36de-86d9-817e0e0a6e45@huawei.com> Date: Thu, 27 Aug 2020 14:41:28 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <20200820143027.3241-4-thunder.leizhen@huawei.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.177.253] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I will drop this patch, because badrange_add() is unlikely to be called. There's no need to care about trivial performance improvements. On 2020/8/20 22:30, Zhen Lei wrote: > Currently, the "struct badrange_entry" has three members: start, length, > list. In append_badrange_entry(), "start" and "length" will be assigned > later, and "list" does not need to be initialized before calling > list_add_tail(). That means, the kzalloc() in badrange_add() or > alloc_and_append_badrange_entry() can be replaced with kmalloc(), because > the zero initialization is not required. > > Signed-off-by: Zhen Lei > --- > drivers/nvdimm/badrange.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/nvdimm/badrange.c b/drivers/nvdimm/badrange.c > index 7f78b659057902d..13145001c52ff39 100644 > --- a/drivers/nvdimm/badrange.c > +++ b/drivers/nvdimm/badrange.c > @@ -37,7 +37,7 @@ static int alloc_and_append_badrange_entry(struct badrange *badrange, > { > struct badrange_entry *bre; > > - bre = kzalloc(sizeof(*bre), flags); > + bre = kmalloc(sizeof(*bre), flags); > if (!bre) > return -ENOMEM; > > @@ -49,7 +49,7 @@ int badrange_add(struct badrange *badrange, u64 addr, u64 length) > { > struct badrange_entry *bre, *bre_new; > > - bre_new = kzalloc(sizeof(*bre_new), GFP_KERNEL); > + bre_new = kmalloc(sizeof(*bre_new), GFP_KERNEL); > > spin_lock(&badrange->lock); > >