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=-6.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 7D567C433DB for ; Wed, 13 Jan 2021 11:23:35 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id ECE4123382 for ; Wed, 13 Jan 2021 11:23:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ECE4123382 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 5541B8D0048; Wed, 13 Jan 2021 06:23:34 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 4DCD78D0047; Wed, 13 Jan 2021 06:23:34 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3CBC88D0048; Wed, 13 Jan 2021 06:23:34 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0070.hostedemail.com [216.40.44.70]) by kanga.kvack.org (Postfix) with ESMTP id 23B898D0047 for ; Wed, 13 Jan 2021 06:23:34 -0500 (EST) Received: from smtpin18.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id DF8FE1EF1 for ; Wed, 13 Jan 2021 11:23:33 +0000 (UTC) X-FDA: 77700516306.18.train62_4b0168f2751d Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin18.hostedemail.com (Postfix) with ESMTP id B9652100ED0F8 for ; Wed, 13 Jan 2021 11:23:33 +0000 (UTC) X-HE-Tag: train62_4b0168f2751d X-Filterd-Recvd-Size: 2726 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf03.hostedemail.com (Postfix) with ESMTP for ; Wed, 13 Jan 2021 11:23:33 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 77B8A2336F; Wed, 13 Jan 2021 11:23:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1610537012; bh=0NYgjzOjhml2lGW631C9LPIJcfCrwDvm/lToJKYk97w=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ZQggGfq4UfTT6N0VnGCvSlr57fPvQX3aWyYIUSBLbuQN1ynmtCxF8707RmjryVg4i VftYT/t7B9TaAPWH8D47dD5t4RVcFCCoBQY7yGCsB1C8IMtv8pjz/b+t3Jr3u2kg36 EEOh8rAZSBgPENFUATLWdpQNGLYiU8RuSLQBtrz6aAs+m3ETRHRPdK0clYH3kCkCSt bIOs5hpRjqeAVGR3mVD2kTbZg9r17upjwjHr8wUiO16gE6fI/RDRzhEiip/MfjDoqo m9qLMdCswtMDkRIKn6vFmyboWMo4+rfp9eHtVYoIkmtCn0j2YFn4br28KDhhaLfFqF dM1VnzAOYdXhg== Date: Wed, 13 Jan 2021 13:23:22 +0200 From: Mike Rapoport To: Oscar Salvador Cc: Andrew Morton , Andrea Arcangeli , Baoquan He , Borislav Petkov , David Hildenbrand , "H. Peter Anvin" , Ingo Molnar , Mel Gorman , Michal Hocko , Mike Rapoport , Qian Cai , Thomas Gleixner , Vlastimil Babka , linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org Subject: Re: [PATCH v3 1/2] x86/setup: don't remove E820_TYPE_RAM for pfn 0 Message-ID: <20210113112322.GG1106298@kernel.org> References: <20210111194017.22696-1-rppt@kernel.org> <20210111194017.22696-2-rppt@kernel.org> <20210113085644.GA24816@linux> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210113085644.GA24816@linux> X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Jan 13, 2021 at 09:56:49AM +0100, Oscar Salvador wrote: > On Mon, Jan 11, 2021 at 09:40:16PM +0200, Mike Rapoport wrote: > > From: Mike Rapoport > > > > The first 4Kb of memory is a BIOS owned area and to avoid its allocation > > for the kernel it was not listed in e820 tables as memory. As the result, > > pfn 0 was never recognised by the generic memory management and it is not a > > part of neither node 0 nor ZONE_DMA. > > So, since it never was added to memblock.memory structs, it was not > initialized by init_unavailable_mem, right? Actually it was initialized by init_unavailable_mem() and got zone=0 and node=0, but the DMA zone started from pfn 1, so pfn 0 was never a part of ZONE_DMA. > -- > Oscar Salvador > SUSE L3 -- Sincerely yours, Mike.