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 AFA55C433FF for ; Sun, 28 Jul 2019 11:19:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 937B521655 for ; Sun, 28 Jul 2019 11:19:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726109AbfG1LTc (ORCPT ); Sun, 28 Jul 2019 07:19:32 -0400 Received: from foss.arm.com ([217.140.110.172]:60268 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725977AbfG1LTa (ORCPT ); Sun, 28 Jul 2019 07:19:30 -0400 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 A1C89344; Sun, 28 Jul 2019 04:19:29 -0700 (PDT) Received: from [10.163.1.126] (unknown [10.163.1.126]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 855083F71F; Sun, 28 Jul 2019 04:19:23 -0700 (PDT) Subject: Re: [PATCH v9 00/21] Generic page walk and ptdump To: Steven Price , linux-mm@kvack.org Cc: Andy Lutomirski , Ard Biesheuvel , Arnd Bergmann , Borislav Petkov , Catalin Marinas , Dave Hansen , Ingo Molnar , James Morse , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Peter Zijlstra , Thomas Gleixner , Will Deacon , x86@kernel.org, "H. Peter Anvin" , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Mark Rutland , "Liang, Kan" , Andrew Morton References: <20190722154210.42799-1-steven.price@arm.com> From: Anshuman Khandual Message-ID: <794fb469-00c8-af10-92a8-cb7c0c83378b@arm.com> Date: Sun, 28 Jul 2019 16:50:03 +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: <20190722154210.42799-1-steven.price@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/22/2019 09:11 PM, Steven Price wrote: > Steven Price (21): > arc: mm: Add p?d_leaf() definitions > arm: mm: Add p?d_leaf() definitions > arm64: mm: Add p?d_leaf() definitions > mips: mm: Add p?d_leaf() definitions > powerpc: mm: Add p?d_leaf() definitions > riscv: mm: Add p?d_leaf() definitions > s390: mm: Add p?d_leaf() definitions > sparc: mm: Add p?d_leaf() definitions > x86: mm: Add p?d_leaf() definitions The set of architectures here is neither complete (e.g ia64, parisc missing) nor does it only include architectures which had previously enabled PTDUMP like arm, arm64, powerpc, s390 and x86. Is there any reason for this set of archs to be on the list and not the others which are currently falling back on generic p?d_leaf() defined later in the series ? Are the missing archs do not have huge page support in the MMU ? If there is a direct dependency for these symbols with CONFIG_HUGETLB_PAGE then it must be checked before falling back on the generic ones. Now that pmd_leaf() and pud_leaf() are getting used in walk_page_range() these functions need to be defined on all arch irrespective if they use PTDUMP or not or otherwise just define it for archs which need them now for sure i.e x86 and arm64 (which are moving to new generic PTDUMP framework). Other archs can implement these later.