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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 32706C282DA for ; Wed, 17 Apr 2019 14:33:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0A759206BA for ; Wed, 17 Apr 2019 14:33:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732593AbfDQOdb (ORCPT ); Wed, 17 Apr 2019 10:33:31 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:45810 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732557AbfDQOd3 (ORCPT ); Wed, 17 Apr 2019 10:33:29 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 96F8BA78; Wed, 17 Apr 2019 07:33:28 -0700 (PDT) Received: from [10.1.196.69] (e112269-lin.cambridge.arm.com [10.1.196.69]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E33E03F557; Wed, 17 Apr 2019 07:33:24 -0700 (PDT) Subject: Re: [PATCH v8 00/20] Convert x86 & arm64 to use generic page walk To: Dave Hansen , linux-mm@kvack.org, Linus Torvalds Cc: Mark Rutland , Dave Hansen , Arnd Bergmann , Ard Biesheuvel , Peter Zijlstra , Catalin Marinas , x86@kernel.org, Will Deacon , linux-kernel@vger.kernel.org, =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Ingo Molnar , Borislav Petkov , Andy Lutomirski , "H. Peter Anvin" , James Morse , Thomas Gleixner , Andrew Morton , linux-arm-kernel@lists.infradead.org, "Liang, Kan" References: <20190403141627.11664-1-steven.price@arm.com> <4e804c87-1788-8903-ccc9-55953aa6da36@arm.com> <3b9561d0-3bde-ef7a-0313-c2cc6216f94d@intel.com> From: Steven Price Message-ID: <3acbf061-8c97-55eb-f4b6-163a33ea4d73@arm.com> Date: Wed, 17 Apr 2019 15:28:54 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <3b9561d0-3bde-ef7a-0313-c2cc6216f94d@intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/04/2019 15:44, Dave Hansen wrote: > On 4/10/19 7:56 AM, Steven Price wrote: >> Gentle ping: who can take this? Is there anything blocking this series? > > First of all, I really appreciate that you tried this. Every open-coded > page walk has a set of common pitfalls, but is pretty unbounded in what > kinds of bugs it can contain. I think this at least gets us to the > point where some of those pitfalls won't happen. That's cool, but I'm a > worried that it hasn't gotten easier in the end. My plan was to implement the generic infrastructure and then work to remove the per-arch code for ptdump debugfs where possible. This patch series doesn't actually get that far because I wanted to get some confidence that the general approach would be accepted. > Linus also had some strong opinions in the past on how page walks should > be written. He needs to have a look before we go much further. Fair enough. I'll post the initial work I've done on unifying the x86/arm64 ptdump code - the diffstat is a bit nicer on that - but there's still work to be done so I'm posting just as an RFC. Thanks, Steve