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=-5.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, URIBL_BLOCKED,USER_AGENT_MUTT 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 595F2C4360F for ; Fri, 5 Apr 2019 05:54:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 28B7A21850 for ; Fri, 5 Apr 2019 05:54:28 +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="hnr5WZBW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729142AbfDEFy0 (ORCPT ); Fri, 5 Apr 2019 01:54:26 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:54834 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725955AbfDEFy0 (ORCPT ); Fri, 5 Apr 2019 01:54:26 -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=0ElSP3JGAMxV4PKBAmgjNsswF1zAiAvQvIKeo2t7kxM=; b=hnr5WZBWyfpphSungyKH/Ftql 2oJOBCJIov3AJuJeOLyOeEgeArN04VHM6qloJubeFhyG0yYlrINWiViVbb4IFcDBXwBbWEWRv9qEs h/CI0LZqgO+Q3uqsX5rJKmezWn3HKcXOPX8UGN+db8qfBawiWTjMdR2rFiJLXT4x5XzW8/Yi57SGI x2gwwLUovAW5hNYT1XcKCJLBgFlflgjGHWYPuy6CA9qbdZJ1HPGjQojH8oQ6bTNrS49XolqXjRkI7 EFkleg2rz77pe1mivc4yMbc2wKou53PibtRP9v2RbdOPq07P9aj9J5Bqi9kH/k0S44tVCUqM+X/nk zV4UlEFWg==; Received: from hch by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1hCHnx-0001w0-Ii; Fri, 05 Apr 2019 05:54:21 +0000 Date: Thu, 4 Apr 2019 22:54:21 -0700 From: Christoph Hellwig To: Anup Patel Cc: Palmer Dabbelt , Albert Ou , Atish Patra , Christoph Hellwig , Paul Walmsley , Mike Rapoport , "linux-riscv@lists.infradead.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v3] RISC-V: Fix Maximum Physical Memory 2GiB option for 64bit systems Message-ID: <20190405055421.GA7087@infradead.org> References: <20190405054909.3238-1-anup.patel@wdc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190405054909.3238-1-anup.patel@wdc.com> User-Agent: Mutt/1.9.2 (2017-12-15) 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 Fri, Apr 05, 2019 at 05:49:34AM +0000, Anup Patel wrote: > The Maximum Physical Memory 2GiB option for 64bit systems is currently > broken because kernel hangs at boot-time when this option is enabled > and the underlying system has more than 2GiB memory. > > This issue can be easily reproduced on SiFive Unleashed board where > we have 8GiB of memory. > > This patch fixes above issue by removing unusable memory region in > setup_bootmem(). > > Signed-off-by: Anup Patel > Reviewed-by: Christoph Hellwig Btw, what is the rationale behind even offering the 2GiB option and the medlow model on 64-bit? Do we reall have use cases where the slightly more effient generated code matters so much to keep up the support burden of this mostly unused and unusual configuration?