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=-5.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,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 57438C433E2 for ; Tue, 8 Sep 2020 11:33:47 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E144821532 for ; Tue, 8 Sep 2020 11:33:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="SFBtG9RO" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E144821532 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Xx/FDaYz9NTG/7o22PP0eKOAZ4CSDlFP3onjm5SdEXQ=; b=SFBtG9ROJxeoZx7kAY5d5zVWH p+p9XAhAHzPfw3VIKzMn928UJPu6eByU7MmWU1jFVBbCYHMl4w2JX8dVTHu4D9nquEn7a+XkyOmxH m0ykQU4KtM6N8i20Tv0AJXseRULiY2GJ6coiysXwUh4H1shcGsi6tuqoFIr3fwqfMCRuy3bHzH7di jFoX8y0GrwKf4edVKmxUIIWZdGIselsg3jqoaprfC93IU1NSX9eeEWRtTEVtZCtPUY3pXzotq8V5p eX1R+XEfS+3Y6CqLTtlJ5yPRDzD4d5DhVfxToQsZr65AE+3kyzXK+DcqjMkHvjtU/rW0xnFaN6xdi TScAsqN2w==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kFbrK-00046B-PJ; Tue, 08 Sep 2020 11:32:22 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kFbrG-00044h-UA for linux-arm-kernel@lists.infradead.org; Tue, 08 Sep 2020 11:32:20 +0000 Received: from gaia (unknown [46.69.195.48]) (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 6AB9520936; Tue, 8 Sep 2020 11:32:13 +0000 (UTC) Date: Tue, 8 Sep 2020 12:32:11 +0100 From: Catalin Marinas To: Anshuman Khandual Subject: Re: [PATCH 1/2] arm64/mm: Change THP helpers to comply with generic MM semantics Message-ID: <20200908113210.GC25591@gaia> References: <1597655984-15428-1-git-send-email-anshuman.khandual@arm.com> <1597655984-15428-2-git-send-email-anshuman.khandual@arm.com> <20200903165631.GC31409@gaia> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200908_073219_095768_D0A31560 X-CRM114-Status: GOOD ( 17.05 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Suzuki Poulose , Marc Zyngier , linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, will@kernel.org, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Sep 08, 2020 at 03:48:08PM +0530, Anshuman Khandual wrote: > On 09/03/2020 10:26 PM, Catalin Marinas wrote: > > On Mon, Aug 17, 2020 at 02:49:43PM +0530, Anshuman Khandual wrote: > >> pmd_present() and pmd_trans_huge() are expected to behave in the following > >> manner during various phases of a given PMD. It is derived from a previous > >> detailed discussion on this topic [1] and present THP documentation [2]. > >> > >> pmd_present(pmd): > >> > >> - Returns true if pmd refers to system RAM with a valid pmd_page(pmd) > >> - Returns false if pmd does not refer to system RAM - Invalid pmd_page(pmd) > > > > The second bullet doesn't make much sense. If you have a pmd mapping of > > some I/O memory, pmd_present() still returns true (as does > > pte_present()). > > Derived this from an earlier discussion (https://lkml.org/lkml/2018/10/17/231) > but current representation here might not be accurate. > > Would this be any better ? > > pmd_present(pmd): > > - Returns true if pmd refers to system RAM with a valid pmd_page(pmd) > - Returns false if pmd refers to a migration or swap entry Yes, that's better -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel