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=-2.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 EBAF3C433FF for ; Wed, 7 Aug 2019 05:29:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C4B6E218CA for ; Wed, 7 Aug 2019 05:29:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="nCFuvFNj" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726424AbfHGF3K (ORCPT ); Wed, 7 Aug 2019 01:29:10 -0400 Received: from mail-pl1-f193.google.com ([209.85.214.193]:37724 "EHLO mail-pl1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725972AbfHGF3K (ORCPT ); Wed, 7 Aug 2019 01:29:10 -0400 Received: by mail-pl1-f193.google.com with SMTP id b3so38930942plr.4 for ; Tue, 06 Aug 2019 22:29:10 -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:user-agent; bh=1vTjKKjPXcwvezFpuQlHk79++RRKGCelf1VGueOrrEQ=; b=nCFuvFNjI+cgrH3oDF1fIJi/Gq7hJFsokBsK8Uk0siw2EVuKNJSVN0AMOq6AEhD4Dx E6gEWGICMUy//3HQJjqquj7/B4tN4HRsxaKuilwqEnslFkay5kXcE4m4Z+7pnIfDNX4z J2MmaMZx/wIlbGaJqxZafWOrIgP0h2OmTm+nFq+KC5BQjgYoFj4YY61UuWYfPrzIK1NE OeM5sPFCAxPN4PUucNSQx0XuJcGZW5qJ7jDu+Ylt3wKlLwGa3tGfCcU6uunEtQEA6FsO GrtjjJOB+u2Fqwe4751ta6gDwDK1jAz6djR9iimXtoy14zH+CavZcZL7RtJ9tlZ9aCbF f4qw== 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:user-agent; bh=1vTjKKjPXcwvezFpuQlHk79++RRKGCelf1VGueOrrEQ=; b=lHzlayfFxfjXjrBGu0VF1XeNmPtn77BFFBuZODudJNxkefBWNL+Awgr1IAhWk1ZxgW p4Fmlz13+lbLeRuFJ8ZnQ2Eteki/H0cAFYBSQL+XvfOecqa9lgGCC+BfNgPbjTxKx1TP 30j3DimUo2WE+HNfaKsqHKaClckPcwAwxib+XvtWZs4IWmK9GNxTFLC/LF9XpfWAeHd6 3AT6npENfEy5V31B0uz+ZwxePHtHkJ+a0/k5osGPnI+b2k0ITDZHeW7bVq3aE3UOhv/k JiDWC3KfENH93ktAEstAMcyz1iKi8biHPsEKG0zcXYkQqCpHsaRAeZtwCgTEvlmpI975 1AlQ== X-Gm-Message-State: APjAAAUWq9CWI9LcPlGQX+wJIc5A3EtNzQgvQi9edbO1ngQZ2eqnWYyS mujbRxQ6jUqeXyxSPfNOHQ== X-Google-Smtp-Source: APXvYqy8DYamhO+Xxeu70pQ++qwQXuBclAgixKYv4wKka+YwFq7p/cQW6qI5JZSet/yTl8yH7Gy/lg== X-Received: by 2002:a17:90a:30cf:: with SMTP id h73mr6810509pjb.42.1565155748748; Tue, 06 Aug 2019 22:29:08 -0700 (PDT) Received: from mypc ([209.132.188.80]) by smtp.gmail.com with ESMTPSA id v63sm91853525pfv.174.2019.08.06.22.29.05 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Tue, 06 Aug 2019 22:29:08 -0700 (PDT) Date: Wed, 7 Aug 2019 13:28:58 +0800 From: Pingfan Liu To: Matthew Wilcox Cc: linux-mm@kvack.org, =?iso-8859-1?B?Suly9G1l?= Glisse , Andrew Morton , Mel Gorman , Jan Kara , "Kirill A. Shutemov" , Michal Hocko , Mike Kravetz , Andrea Arcangeli , linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/3] mm/migrate: clean up useless code in migrate_vma_collect_pmd() Message-ID: <20190807052858.GA9749@mypc> References: <1565078411-27082-1-git-send-email-kernelfans@gmail.com> <20190806133503.GC30179@bombadil.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190806133503.GC30179@bombadil.infradead.org> User-Agent: Mutt/1.11.3 (2019-02-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 06, 2019 at 06:35:03AM -0700, Matthew Wilcox wrote: > > This needs something beyond the subject line. Maybe ... > > After these assignments, we either restart the loop with a fresh variable, > or we assign to the variable again without using the value we've assigned. > > Reviewed-by: Matthew Wilcox (Oracle) > > > goto next; > > } > > - pfn = page_to_pfn(page); > > After you've done all this, as far as I can tell, the 'pfn' variable is > only used in one arm of the conditions, so it can be moved there. > > ie something like: > > - unsigned long mpfn, pfn; > + unsigned long mpfn; > ... > - pfn = pte_pfn(pte); > ... > + unsigned long pfn = pte_pfn(pte); > + > This makes code better. Thank you for the suggestion. Will send v2 for this patch. Regards, Pingfan