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_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, 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 CC032CA9EA9 for ; Fri, 18 Oct 2019 14:25:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A1B7221897 for ; Fri, 18 Oct 2019 14:25:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="uvI7mKv4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2634130AbfJROZ0 (ORCPT ); Fri, 18 Oct 2019 10:25:26 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:34994 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730937AbfJROZ0 (ORCPT ); Fri, 18 Oct 2019 10:25:26 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=jcc1+ecujeFP9amWaaEK0sWmcb9810FGXg7viupUUuw=; b=uvI7mKv4KgeqsE8Kvolcfmo+a P+z6BiDQNqceXE9dwMVcat/M3UZU70pZTGU1DeCqwPQwUi5YvvBUce17id8+Bj/LangeR+r/Qsvhw 3b17jFLtLzh5j6raTeO/jvrHNRwvVikywv0lJokbuLnvoObWEFTPBRn0NSazfEU5/NKDkAmMNBQQp tGDszPqsOU8VWIQ9bKfSBMiEjQRRmTP4/2laIqNrrXBxXuJigUUAKcIAnpIEE0WlaYYglTe4JSeNd DBNG2jH3S/zIkjBTtNsHl8bsPkUsUmDrZ/2fbzuS4+6HegzlBSSYLAt5K6BdU0N7QONuUeCeTNuhY Zl4EgwyAQ==; Received: from willy by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1iLTBz-0001xl-Gq; Fri, 18 Oct 2019 14:25:23 +0000 Date: Fri, 18 Oct 2019 07:25:23 -0700 From: Matthew Wilcox To: Song Liu Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, matthew.wilcox@oracle.com, kernel-team@fb.com, william.kucharski@oracle.com, kirill.shutemov@linux.intel.com, Johannes Weiner , Hugh Dickins Subject: Re: [PATCH] mm,thp: recheck each page before collapsing file THP Message-ID: <20191018142523.GL32665@bombadil.infradead.org> References: <20191018050832.1251306-1-songliubraving@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191018050832.1251306-1-songliubraving@fb.com> User-Agent: Mutt/1.12.1 (2019-06-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 17, 2019 at 10:08:32PM -0700, Song Liu wrote: > + /* double check the page is correct and clean */ > + if (unlikely(!PageUptodate(page)) || > + unlikely(PageDirty(page)) || > + unlikely(page->mapping != mapping)) { That's kind of an ugly way of writing it. Why not more simply: if (unlikely(!PageUptodate(page) || PageDirty(page) || page->mapping != mapping)) {