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=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 CCDC3C32751 for ; Wed, 7 Aug 2019 15:12:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A06AA21BF2 for ; Wed, 7 Aug 2019 15:12:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="udjl5wYe" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388178AbfHGPMb (ORCPT ); Wed, 7 Aug 2019 11:12:31 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:35086 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726773AbfHGPMb (ORCPT ); Wed, 7 Aug 2019 11:12:31 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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: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=SXYk4z8+XUcrwUH0ETJaYqTcSP2s+uqNvgDYI9B18iM=; b=udjl5wYerj8dDNl2/fe+MAu0v f/qpzJRnWO7ODN7/yx2FSts8Kyy/VfdtWN5KqxBo5hatblPpnqCq9omj1Og+q0enzLXvAUS+R8cKX SMrL74pvvUCrOIhjyOxcGuxDPIldGfpkiLR2K0C9dHQxvDpVWjWJS6asUIY0mTYOGj2iMbYr0jYhV pxwdwQl6kVq61ioceD4eVKLupH/2Gnf0vDW/ekvUkJEdin9WBef+/s4DMwW7Sovp52ML9t5PjNzW0 RxppFwk0RbheSj5EqY/F+dnNjEgWx/PWSYymR6ZFWmBosM0tSt0dslaoSGH9FhjduHmTLL3Omp+cP +RCtISIIA==; Received: from hch by bombadil.infradead.org with local (Exim 4.92 #3 (Red Hat Linux)) id 1hvNc6-0004bD-1i; Wed, 07 Aug 2019 15:12:30 +0000 Date: Wed, 7 Aug 2019 08:12:30 -0700 From: Christoph Hellwig To: Alexandre Ghiti Cc: Christoph Hellwig , Paul Walmsley , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] riscv: kbuild: add virtual memory system selection Message-ID: <20190807151229.GA16432@infradead.org> References: <20190802084453.GA1410@infradead.org> <20190807054246.GB1398@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.11.4 (2019-03-13) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 07, 2019 at 09:04:40AM +0200, Alexandre Ghiti wrote: > I took a look at how x86 deals with 5-level page table: it allows to handle > 5-level and 4-level at runtime by folding the last page table level (cf > Documentation/x86/x86_64/5level-paging.rst). So we might want to be able to > do the same and deal with that at runtime. Yes, following the X86_5LEVEL model is the right thing.