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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 68F8ECA0FED for ; Tue, 9 Sep 2025 22:39:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:MIME-Version:Message-ID:References:In-Reply-To:Subject:CC:To: From:Date:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=o4pJzl4BWqncjRLwqdCVSmCaOJCq8m9Ifms3vJmzKBM=; b=RSYL126We6prTzYa0CpIUcNSgZ rJBv1qHpNYKSZu8+rS03vExVvZUP5bbwBOwvRQeavWlF5DeSRb4egVppwppPdvmuL/KlQW3l8BcSe MsB01P39PLmZfJ294EnPDYADZGQketcynH445u4kK5+oxl0DLztNpw43Sb2gSEOqTmTY1Zpd5oRqY K7V2EfwlnS/Lx+ORASbWgduq1Ag3Vtxs2POsKVdlI+l9v2d1Jk9BspsOqZZB4NhHUNPtq2KHSwv17 swZnJaehl+jgYuGlHs81T2VAclVZUtZ3uCfTkQUkmD4VPhnuziwBPTZiuDy0Z75lqqHnggv5ggozK Z2TceHHA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uw6zy-0000000AiDU-2qhp; Tue, 09 Sep 2025 22:39:38 +0000 Received: from terminus.zytor.com ([2607:7c80:54:3::136] helo=mail.zytor.com) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uw6zw-0000000AiCf-0khc for linux-arm-kernel@lists.infradead.org; Tue, 09 Sep 2025 22:39:37 +0000 Received: from ehlo.thunderbird.net (c-76-133-66-138.hsd1.ca.comcast.net [76.133.66.138]) (authenticated bits=0) by mail.zytor.com (8.18.1/8.17.1) with ESMTPSA id 589Md5a71810392 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NO); Tue, 9 Sep 2025 15:39:05 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 589Md5a71810392 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2025082201; t=1757457547; bh=o4pJzl4BWqncjRLwqdCVSmCaOJCq8m9Ifms3vJmzKBM=; h=Date:From:To:CC:Subject:In-Reply-To:References:From; b=TvOUc/rvPHuoAgZik4kP6Jrk/1+TPY9+I66slCEYRMAAVaJliSrzt+2sOFL7uxfep TkUyZI254fJRZ0lrODF9atINh0A8S4jLrAmCkJHU6JXLFZKZC0KSUVdi0tmre9KWKN XbKdciAhvqcaNOwc7fFmyUBOA5BxnpqIS4Eb0rGthQiBgS5HHj+CzVzQJOWVF0iflT tgpvUETHe9/40V2F6BCYuDmvwT7GfqNk48CbFXskPApkAJTXDi/C8HYPbnObeJPLQM 4VGzdB3lbm4UCWwMufH5gTZgR2KMO3DzwNg9CgZkrpc9Dml+J/eRl9RSkkGtbvpN2l PQy3pTIde+vBg== Date: Tue, 09 Sep 2025 15:39:05 -0700 From: "H. Peter Anvin" To: Linus Torvalds CC: Arnd Bergmann , ksummit@lists.linux.dev, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-mips@vger.kernel.org, linux-mm@kvack.org, imx@lists.linux.dev, Christophe Leroy , Richard Weinberger , Lucas Stach , Linus Walleij , Geert Uytterhoeven , Ankur Arora , David Hildenbrand , Mike Rapoport , Lorenzo Stoakes , Matthew Wilcox , Andrew Morton , "Liam R. Howlett" , Vlastimil Babka , Suren Baghdasaryan , Ira Weiny , Nishanth Menon , =?ISO-8859-1?Q?Heiko_St=FCbner?= , Alexander Sverdlin , "Chester A. Unal" , Sergio Paracuellos , Andreas Larsson Subject: Re: [TECH TOPIC] Reaching consensus on CONFIG_HIGHMEM phaseout User-Agent: K-9 Mail for Android In-Reply-To: References: <4ff89b72-03ff-4447-9d21-dd6a5fe1550f@app.fastmail.com> Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250909_153936_212826_DF709948 X-CRM114-Status: GOOD ( 13.77 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On September 9, 2025 3:24:29 PM PDT, Linus Torvalds wrote: >On Tue, 9 Sept 2025 at 14:39, H=2E Peter Anvin wrote: >> >> 1 GB systems used highmem too, sadly=2E And 1 GB was the norm for a big= chuck of the late 32-bit era=2E > >Well, while on x86 1GB systems did use highmem, they'd typically not >use very much of it=2E > >IOW, they'd have about 900MB as lowmem (ok, I think it was 896MB to be >exact), with something like 120MB highmem=2E > >So they'd either lose a bit of memory, or they'd use the 2G:2G split=2E > >Or - and I think this is the main point - they'd stay on old kernels >like the ancient museum pieces they are=2E > >I'm not convinced it makes sense to have a modern kernel on a museum piec= e=2E > > Linus > Certainly=2E And the 2:2 split is probably the right thing for the old mac= hines anyway=2E