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=-6.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS autolearn=no 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 19915C43461 for ; Fri, 4 Sep 2020 18:12:52 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 92CB0208DB for ; Fri, 4 Sep 2020 18:12:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="geJYOB2x" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 92CB0208DB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id C65726B006E; Fri, 4 Sep 2020 14:12:50 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C15C48E0003; Fri, 4 Sep 2020 14:12:50 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B059A6B0071; Fri, 4 Sep 2020 14:12:50 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0120.hostedemail.com [216.40.44.120]) by kanga.kvack.org (Postfix) with ESMTP id 971C86B006E for ; Fri, 4 Sep 2020 14:12:50 -0400 (EDT) Received: from smtpin11.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 4713B3624 for ; Fri, 4 Sep 2020 18:12:50 +0000 (UTC) X-FDA: 77226174900.11.smile35_51039b1270b4 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin11.hostedemail.com (Postfix) with ESMTP id 26EBD180F8B81 for ; Fri, 4 Sep 2020 18:12:50 +0000 (UTC) X-HE-Tag: smile35_51039b1270b4 X-Filterd-Recvd-Size: 2922 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf12.hostedemail.com (Postfix) with ESMTP for ; Fri, 4 Sep 2020 18:12:49 +0000 (UTC) Received: from X1 (nat-ab2241.sltdut.senawave.net [162.218.216.4]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9C8AA208CA; Fri, 4 Sep 2020 18:12:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599243168; bh=Id4qhzHOsS6DwGIQ5LVetNXj3LxgcTh1B0kqH3vve5o=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=geJYOB2xEbbkF6OnJWiwu7wzHo+MfStfINict1HWGoIhirYFl0er44nUec+OYyT6I 5bU477LNJafUy+yz95yiwzDBZZFFmKVk1bPChtXZIgy9vdBd3baPfALJQ3DXi4Hau0 TKowc5PUkqMsVKJpY1vfP72u4k/Ge0C++UwD1M68= Date: Fri, 4 Sep 2020 11:12:47 -0700 From: Andrew Morton To: mateusznosek0@gmail.com Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/page_alloc.c: Clean code by removing unnecessary initialization Message-Id: <20200904111247.371e5bfca967239781e5bf27@linux-foundation.org> In-Reply-To: <20200904132422.17387-1-mateusznosek0@gmail.com> References: <20200904132422.17387-1-mateusznosek0@gmail.com> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 26EBD180F8B81 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam05 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000240, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, 4 Sep 2020 15:24:22 +0200 mateusznosek0@gmail.com wrote: > From: Mateusz Nosek > > Previously variable 'tmp' was initialized, but was not read later > before reassigning. So the initialization can be removed. > > ... > > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -5637,7 +5637,7 @@ static int find_next_best_node(int node, nodemask_t *used_node_mask) > int n, val; > int min_val = INT_MAX; > int best_node = NUMA_NO_NODE; > - const struct cpumask *tmp = cpumask_of_node(0); > + const struct cpumask *tmp; > > /* Use the local node if we haven't already */ > if (!node_isset(node, *used_node_mask)) { OK. But we may as well kill tmp altogether? --- a/mm/page_alloc.c~mm-page_allocc-clean-code-by-removing-unnecessary-initialization-fix +++ a/mm/page_alloc.c @@ -5637,7 +5637,6 @@ static int find_next_best_node(int node, int n, val; int min_val = INT_MAX; int best_node = NUMA_NO_NODE; - const struct cpumask *tmp; /* Use the local node if we haven't already */ if (!node_isset(node, *used_node_mask)) { @@ -5658,8 +5657,7 @@ static int find_next_best_node(int node, val += (n < node); /* Give preference to headless and unused nodes */ - tmp = cpumask_of_node(n); - if (!cpumask_empty(tmp)) + if (!cpumask_empty(cpumask_of_node(n))) val += PENALTY_FOR_NODE_WITH_CPUS; /* Slight preference for less loaded node */ _