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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4AF36C43334 for ; Mon, 4 Jul 2022 04:33:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc: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=UE5ruhTWj/IA1mezgtZ4gbXsFNcuLmo4Y7rwvU5/aYY=; b=VSEIeZ2DPcaEeV MqPo+B5LmC4G1xxV9+00PqI9TboIjGSlan3s/8TGLowYvUSD81ycfTRE2jviQOodRrFdUEZfwd3hW rbn6kVO8CC/E3n7nVx1atGkptbpq+zXcAGLOhncgC8Uj7Wy8W4zjXEdW3qIMQc0vENy6WYvzaO85E bifAumsCetlwfQF2WeTtv5Ynmr0my189HOMWmXG8vbtyJVDrHfu/3Znj5+jYCgsOhFDiyWiNvnHRB oXtsZc2gyAjE69vBLcZ/vzNrPOKClFGDJug4ACbqHqfWewJVW89DUwLKIWJg0LFpKodAwCTr0uyXJ U+A6zL5I4fCPx0CMUzfg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1o8DlN-004VwC-QE; Mon, 04 Jul 2022 04:32:45 +0000 Received: from pandora.armlinux.org.uk ([2001:4d48:ad52:32c8:5054:ff:fe00:142]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1o8DlL-004VvK-66 for linux-arm-kernel@lists.infradead.org; Mon, 04 Jul 2022 04:32:44 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: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=YYKbXvB/b/OIVTpzpeh7Y3tTbzRBSh+cFFhkPT74VhM=; b=kGJGgWeKv+2p7fAR+7kqPMnGZO 4kyvqm6bWq+iYc0ZZxH8sVhRcIOXkj5ECpkMpXhj0ZDtpGQ5Ja6Y86MIQOiTvQ62ugNmGHzNAqE+b XTUAc7mjs8xdlunUZG4/zhXv8LDJXZ0A+ex/+1KJaiPBSK25Vx+2MrMI1fB+snkKknCSxjIyYyMkU M5AP2AECWelxZo8oCYVuMfKBy6ewJxe9/JBTOSLz5a5UulWc+XqspUP9nTru3rSOeCITiHYCeJma2 924vw+V1F4fTfts1DsaSY1iEMT9/G8tZUKSLFQhEAB8hdJH5jKSX7R9O69hKLSbWod2Hc3XWRRT56 eHDmZwxw==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:33156) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1o8DlE-0007tN-NS; Mon, 04 Jul 2022 05:32:36 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1o8DlB-0001r8-97; Mon, 04 Jul 2022 05:32:33 +0100 Date: Mon, 4 Jul 2022 05:32:33 +0100 From: "Russell King (Oracle)" To: Matthew Wilcox Cc: Andrew Morton , Arnd Bergmann , Mike Rapoport , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 15/14] arm: Rename PMD_ORDER to PMD_BITS Message-ID: References: <20220703141203.147893-1-rppt@kernel.org> <20220703211441.3981873-1-willy@infradead.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220703_213243_251499_3642A0AC X-CRM114-Status: GOOD ( 17.38 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 Sun, Jul 03, 2022 at 10:54:49PM +0100, Matthew Wilcox wrote: > On Sun, Jul 03, 2022 at 10:16:45PM +0100, Russell King (Oracle) wrote: > > On Sun, Jul 03, 2022 at 10:14:41PM +0100, Matthew Wilcox (Oracle) wrote: > > > This is the number of bits used by a PMD entry, not the order of a PMD. > > > > No, it's not the number of bits. A PMD entry doesn't fit in 2 or 3 bits. > > This is even more confusing. > > Well, what is it then? The order of something is PAGE_SIZE << n, and > that doesn't seem to be what this is. Where is it defined that "order" means "PAGE_SIZE << n" ? "order" here is "order of magnitude" and in this case, it is 2^n, just like order of magnitude in base 10 is 10^n. So strictly, the usage here is completely correct, but if you describe "order" as "PAGE_SIZE << n" that is no longer an order of magnitude, because it doesn't increase in an order of magnitude (iow, n = 2 isn't PAGE_SIZE * PAGE_SIZE). Now, if you're trying to tell me that Linux has decided to define "order" to be something non-standard, I'll accept that, but then we shouldn't be renaming stuff that is using it in a standard way. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last! _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel