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=-8.1 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FSL_HELO_FAKE,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1, USER_IN_DEF_DKIM_WL 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 B9B5BC35242 for ; Fri, 24 Jan 2020 14:02:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 90D76214AF for ; Fri, 24 Jan 2020 14:02:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="L9ErBMyC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389005AbgAXOCp (ORCPT ); Fri, 24 Jan 2020 09:02:45 -0500 Received: from mail-wm1-f65.google.com ([209.85.128.65]:52280 "EHLO mail-wm1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387698AbgAXOCo (ORCPT ); Fri, 24 Jan 2020 09:02:44 -0500 Received: by mail-wm1-f65.google.com with SMTP id p9so1769347wmc.2 for ; Fri, 24 Jan 2020 06:02:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=P//bELOAogzapLRAvc0MrTECr/vkbTdTXm/vZxUoi7A=; b=L9ErBMyCtJKb5ZEZYl3TmzU8EuI/xFUWYDF+VW9m90cvjhClhkYvKXe8R60FO1jApB myLg4r9b28I5Vc+4zNLsdEfYsQ9aWxkO/BdkYOuyV0Au5mSq/4JtRW7JFx3Q9S24CGvD 2Mt0W5leTE7dWl9zVcoVSRPAuGZBK0Oa9tvBEwzJWzXG5ls6izBvvc/iSVkBHUTOe1UN lVmz78njpXZZBYDF4uVoTiXQxlxnKtYYk/B3Bkv9edn4xJEHhsz8BwyM/v73POvMSl67 SKL+XWTPYoyrQQQ9G67iRS++pePFi6hYUxk0uCIipKFSOxIjcgoZK3kfOa46mExL59tk 73/w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=P//bELOAogzapLRAvc0MrTECr/vkbTdTXm/vZxUoi7A=; b=iYigmuAVwfO74C5FwHT7fzErEUiKTAUt+PmAd1ljyZyELGaeJX/X1zFmgiTTUyVScy k+TZUikyagiI6BtpOlui4YiCD4JqUFoCkfdc0CvEHLzoAo58Z+43FiMJISXJE85VRZI7 9+Ml4YOtcIGBqxTxMomkzFLaA+TEl4V3yr76OG55yIQKEXW/5mTXkpRNySUzSQmJUqwr JeFMgOYIt91rPrdgEKOpsvUQETngPFLqMmCv7mX64Q51QyBd+anQ4XTltiiv88IEqENA alMN5iRl02zzigYlS4TNl22jGf8h9ZVfQ8Ipe1DYlfH76MuFpfl9wIXOVo1uehw7UA1Z eyrg== X-Gm-Message-State: APjAAAXYRh/HPeFa5lR9ETw6V7d/eveB8N4ZZiuA2f2msESa4w4aRDcV DWIccFZPCshRfiAliZZ3+CI/739JJ6OTfw== X-Google-Smtp-Source: APXvYqwh++vgRWy9mDsoWvMlmUS3xeKplJZO2IFAv+YwFA/ve3hr0mvoCovh3TlbiktzN44VhH43YQ== X-Received: by 2002:a1c:1b4d:: with SMTP id b74mr1475490wmb.33.1579874562635; Fri, 24 Jan 2020 06:02:42 -0800 (PST) Received: from google.com ([2a00:79e0:d:110:d6cc:2030:37c1:9964]) by smtp.gmail.com with ESMTPSA id o1sm7474771wrn.84.2020.01.24.06.02.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 24 Jan 2020 06:02:41 -0800 (PST) Date: Fri, 24 Jan 2020 14:02:37 +0000 From: Quentin Perret To: Marc Zyngier Cc: Will Deacon , Mike Rapoport , Anshuman Khandual , Catalin Marinas , Russell King , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, Mike Rapoport , kvmarm@lists.cs.columbia.edu, kernel-team@android.com Subject: Re: [PATCH v2 0/1] arm/arm64: add support for folded p4d page tables Message-ID: <20200124140237.GA180536@google.com> References: <20200113111323.10463-1-rppt@kernel.org> <20200122185017.GA17321@willie-the-truck> <20200124122053.GA150292@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday 24 Jan 2020 at 13:34:35 (+0000), Marc Zyngier wrote: > I don't disagree at all. To be honest, I've been on the cusp of getting > rid of it for a while, for multiple reasons: > > - It has no users (as you noticed) > - It is hardly tested (a consequence of the above) > - It isn't feature complete (no debug, no PMU) > - It doesn't follow any of the evolution of the architecture (a more > generic feature of the 32bit port, probably because people run their > 64bit-capable cores in 64bit mode) > - It is becoming a mess of empty stubs > > The maintenance aspect hasn't been a real problem so far. Even the NV > support is only about 200 lines of stubs. But what you have in mind is > going to be much more invasive, and I wouldn't want an unused feature to > get in the way. > > What I may end-up doing is to send a RFC series to remove the 32bit host > support from the tree during in the 5.6 cycle, targeting 5.7. If someone > shouts loudly during that time frame, we keep it and you'll have to work > around it. If nobody cares, then dropping it is the right thing to do. > > Would that be OK with you? Absolutely. And yes, if there are users of the 32 bits port, it'll be on us to work around in a clean way, but I think this is perfectly fair. I'll be happy to try and test your RFC series when it goes on the list if that can help. Thanks! Quentin