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=-3.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 CA1D5C432BE for ; Mon, 30 Aug 2021 07:32:51 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1B63F60FA0 for ; Mon, 30 Aug 2021 07:32:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 1B63F60FA0 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 8B1F98D0001; Mon, 30 Aug 2021 03:32:50 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 861E06B0071; Mon, 30 Aug 2021 03:32:50 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 777AB8D0001; Mon, 30 Aug 2021 03:32:50 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0136.hostedemail.com [216.40.44.136]) by kanga.kvack.org (Postfix) with ESMTP id 6AD4C6B006C for ; Mon, 30 Aug 2021 03:32:50 -0400 (EDT) Received: from smtpin35.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 1BFA122ABF for ; Mon, 30 Aug 2021 07:32:50 +0000 (UTC) X-FDA: 78530930100.35.E6948E0 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf01.hostedemail.com (Postfix) with ESMTP id ABBF55039537 for ; Mon, 30 Aug 2021 07:32:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.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; bh=CsUY/25ldc/6yahhooVuAywYxR4PUqEW9297uxOOCDU=; b=NcP4iF5tJ9VEvyLqe7IMu72O+V I3qr7DNGae5hgE7ncyEKZ/b1464fzo8K97qrKFweFipsAWDDe4ort38XqiYLHu23IPSi/+ozsftoV Mey+aSOuwJBBH9RhEQ8ALrDoYyl2KJlQQC4pFs0RvXdGlsll8GF9WHSO4sY+Ynwh0hrzm4LeEKC1m XZSABurZOxkd/4UD4vruvdg0OcvYk47NN2Ksar/znHeairQJoalg4v0osoxgPMZ/9iDFb9SSrtCdg WIhB2PUbk/k9db0/QbIuv8XmCLSLUTr1l/D+y5qWhHC5l8U2DSYEw6cL4XYbbXKVFq9TGH9NXTuhu 5zrRLB9g==; Received: from hch by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mKbm1-00HSK5-13; Mon, 30 Aug 2021 07:32:10 +0000 Date: Mon, 30 Aug 2021 08:32:05 +0100 From: Christoph Hellwig To: Li Zhijian Cc: linux-mm@kvack.org, linux-rdma@vger.kernel.org, akpm@linux-foundation.org, jglisse@redhat.com, jgg@ziepe.ca, hch@infradead.org, yishaih@nvidia.com, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH v2] mm/hmm: bypass devmap pte when all pfn requested flags are fulfilled Message-ID: References: <20210828010441.3702-1-lizhijian@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210828010441.3702-1-lizhijian@cn.fujitsu.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=NcP4iF5t; spf=none (imf01.hostedemail.com: domain of BATV@casper.srs.infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=BATV@casper.srs.infradead.org; dmarc=none X-Stat-Signature: 5pmdouw8jb81rxaqdbeur5tpgrut9bjj X-Rspamd-Queue-Id: ABBF55039537 X-Rspamd-Server: rspam04 X-HE-Tag: 1630308769-516213 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000057, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Sat, Aug 28, 2021 at 09:04:41AM +0800, Li Zhijian wrote: > + if (!pte_devmap(pte) && pte_special(pte) && > + !is_zero_pfn(pte_pfn(pte))) { Maybe this is a little too superficial and nitpicky, but I find the ordering of the checks a little strange. Why not do the pte_special first and then the exlusions from it later?