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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8DC58C43334 for ; Mon, 4 Jul 2022 14:28:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234472AbiGDO2V (ORCPT ); Mon, 4 Jul 2022 10:28:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58754 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234392AbiGDO2S (ORCPT ); Mon, 4 Jul 2022 10:28:18 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A40CE6367 for ; Mon, 4 Jul 2022 07:28:16 -0700 (PDT) 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=BNvWRWw003hywMuVmvZBynD2U4e1aMJSqur83vbYrqE=; b=D6tcueKTPe7HB/QbakEkCppG8L vs2OnJ1O+5QUp18jCp33mtP/Cy7QnfiziCwALkBdd/b6swQ7jZT8iyCmWKaZOXHpQGhSgTasOHNSS KgHAl0WZLVAneVqLhWZBmkp0GX8deWFe7ozlhc8PgXogAwWIghR25lB3WywVvJAtxqQKqpoj2NbeY ed0RzRCfVuPIPNbHqSKChSRxO4o9lHdiaXcKCPcXFFThahGN1JP6k15DZZYMsLShWGqoCGT+qASin bOuOcMCEYoynMy0LO/UmxBNImQL+laL/n6Q6reZkb1A4w211JwYGluvtZ3075/sqJeqQT14lexJHr wihARMTA==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1o8N3X-00HMPh-BQ; Mon, 04 Jul 2022 14:28:07 +0000 Date: Mon, 4 Jul 2022 15:28:07 +0100 From: Matthew Wilcox To: "Russell King (Oracle)" 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-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 04, 2022 at 12:32:20PM +0100, Russell King (Oracle) wrote: > On Mon, Jul 04, 2022 at 11:48:39AM +0100, Matthew Wilcox wrote: > > On Mon, Jul 04, 2022 at 05:32:33AM +0100, Russell King (Oracle) wrote: > > > 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" ? > > > > include/asm-generic/getorder.h: * get_order - Determine the allocation order of a memory size > > I really don't care - "order" is something that is a standard term, The word "order" has many different uses, just in mathematics alone (to say nothing of its uses in biology, business, the military, religion, or signal processing). https://en.wikipedia.org/wiki/Order_(mathematics) > and is entirely appropriate in its use in this case. The fact is, > this use conforms to the standard term usage, not some made up > Linux whim. At the point where you're talking about PMD order, you're in the realm of memory management, and using terms to mean something different from their normal meaning within mm is only going to lead to confusion.