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[23.128.96.18]) by mx.google.com with ESMTP id z5si4665227ejd.322.2020.09.04.11.14.53; Fri, 04 Sep 2020 11:15:15 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=geJYOB2x; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726184AbgIDSMu (ORCPT + 99 others); Fri, 4 Sep 2020 14:12:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:52634 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726109AbgIDSMt (ORCPT ); Fri, 4 Sep 2020 14:12:49 -0400 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 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 */ _