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=-2.3 required=3.0 tests=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 CB691C2BA19 for ; Tue, 21 Apr 2020 08:09:39 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 8FFB720B1F for ; Tue, 21 Apr 2020 08:09:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8FFB720B1F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 1AA528E0005; Tue, 21 Apr 2020 04:09:39 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 133978E0003; Tue, 21 Apr 2020 04:09:39 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F3C988E0005; Tue, 21 Apr 2020 04:09:38 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0054.hostedemail.com [216.40.44.54]) by kanga.kvack.org (Postfix) with ESMTP id D97768E0003 for ; Tue, 21 Apr 2020 04:09:38 -0400 (EDT) Received: from smtpin14.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 9556C181AEF00 for ; Tue, 21 Apr 2020 08:09:38 +0000 (UTC) X-FDA: 76731138036.14.pies76_542247f8d8424 X-HE-Tag: pies76_542247f8d8424 X-Filterd-Recvd-Size: 4105 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf36.hostedemail.com (Postfix) with ESMTP for ; Tue, 21 Apr 2020 08:09:37 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 0B5261FB; Tue, 21 Apr 2020 01:09:37 -0700 (PDT) Received: from [10.163.1.9] (unknown [10.163.1.9]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 03BAA3F6CF; Tue, 21 Apr 2020 01:09:29 -0700 (PDT) Subject: Re: [PATCH 2/2] mm/thp: Rename pmd_mknotpresent() as pmd_mknotvalid() To: Will Deacon Cc: linux-mm@kvack.org, Vineet Gupta , Russell King , Catalin Marinas , Thomas Bogendoerfer , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Steven Rostedt , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Andrew Morton , nouveau@lists.freedesktop.org, linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org References: <1584680057-13753-1-git-send-email-anshuman.khandual@arm.com> <1584680057-13753-3-git-send-email-anshuman.khandual@arm.com> <20200420210354.GD29998@willie-the-truck> <78fee884-78fc-6102-1a37-12106dc21336@arm.com> <20200421070703.GC14448@willie-the-truck> From: Anshuman Khandual Message-ID: <73e2d20a-4009-c2f3-03b7-fcd29d098491@arm.com> Date: Tue, 21 Apr 2020 13:39:15 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20200421070703.GC14448@willie-the-truck> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 04/21/2020 12:37 PM, Will Deacon wrote: > On Tue, Apr 21, 2020 at 04:57:26AM +0530, Anshuman Khandual wrote: >> >> >> On 04/21/2020 02:33 AM, Will Deacon wrote: >>> On Fri, Mar 20, 2020 at 10:24:17AM +0530, Anshuman Khandual wrote: >>>> pmd_present() is expected to test positive after pmdp_mknotpresent() as the >>>> PMD entry still points to a valid huge page in memory. pmdp_mknotpresent() >>>> implies that given PMD entry is just invalidated from MMU perspective while >>>> still holding on to pmd_page() referred valid huge page thus also clearing >>>> pmd_present() test. This creates the following situation which is counter >>>> intuitive. >>>> >>>> [pmd_present(pmd_mknotpresent(pmd)) = true] >>>> >>>> This renames pmd_mknotpresent() as pmd_mknotvalid() reflecting the helper's >>>> functionality more accurately while changing the above mentioned situation >>>> as follows. This does not create any functional change. >>>> >>>> [pmd_present(pmd_mknotvalid(pmd)) = true] >>>> >>>> This is not applicable for platforms that define own pmdp_invalidate() via >>>> __HAVE_ARCH_PMDP_INVALIDATE. Suggestion for renaming came during a previous >>>> discussion here. >>> >>> Bikeshed alert: maybe pmd_mkinvalid() would be better, given that this is >>> a one-trick pony for pmdp_invalidate()? >> >> I had thought about making it pmd_mkinvalid() earlier. But as we were replacing >> pmd_mknotpresent(), hence went with similar pattern pmd_mknotvalid() which was >> originally suggested by Catalin. There is an existing pte_mknotpresent() in arc >> platform as well. I dont have a very strong opinion either way, will be happy >> to rename. But then still wondering if we really need to. > > I just think that having pmdp_invalidate() call pmd_mkinvalid() makes a lot > of sense and, since this is a pure renaming patch, then that's worth taking > into consideration. Sure np, will do. > > If you go with pmd_mkinvalid(), then: > > Acked-by: Will Deacon > > Will >