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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id D3608C3DA6D for ; Fri, 16 May 2025 13:45:14 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 083416B0180; Fri, 16 May 2025 09:45:13 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 032D06B0182; Fri, 16 May 2025 09:45:12 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E3CA56B0183; Fri, 16 May 2025 09:45:12 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id C10586B0180 for ; Fri, 16 May 2025 09:45:12 -0400 (EDT) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id A43E580609 for ; Fri, 16 May 2025 13:45:13 +0000 (UTC) X-FDA: 83448892506.22.8DCFDDE Received: from nyc.source.kernel.org (nyc.source.kernel.org [147.75.193.91]) by imf13.hostedemail.com (Postfix) with ESMTP id 08A9320006 for ; Fri, 16 May 2025 13:45:11 +0000 (UTC) Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=C57zkcZH; spf=pass (imf13.hostedemail.com: domain of mingo@kernel.org designates 147.75.193.91 as permitted sender) smtp.mailfrom=mingo@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1747403112; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=AGmEi6K6CoHZUiY54V26xwLogSyLFIJA4Ty83UBIu2s=; b=4PBpIM1O47NS3ALZiv08qfgdNvDlRRECXcCIqHMJoukQD/hyafWieHEtKdCClxhbKr6qso sk5EERAjx8gxumHJU6OuQFwEPIgzhyPHVBdqQdSbRjyxFfLt+woMEfijunkNGmaJadxqDu zSqmz0afhByjJEW6ODBsjKZDL37G7+E= ARC-Authentication-Results: i=1; imf13.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=C57zkcZH; spf=pass (imf13.hostedemail.com: domain of mingo@kernel.org designates 147.75.193.91 as permitted sender) smtp.mailfrom=mingo@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1747403112; a=rsa-sha256; cv=none; b=KZgaicHD4yPzhrkPoiC3VzorejH+ZVNbN9K7WtbZc5xJMOGl3U7QauVYEBWbesw33lJfy4 fAwwZpRMpQBpjeSPKAy6tq9KxJTjh6FRWrdHy+/Tfl6OcqyL/gLTrlsC1DKWK/UvEkr3bj y8SRWgPfBsJPC12SZ3S/rSr5pQTWF4o= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id 52598A4E7FA; Fri, 16 May 2025 13:45:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0045FC4CEE4; Fri, 16 May 2025 13:45:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1747403111; bh=NqMcz7kAbb5aJvvP9l+89oIjYYRsc8K6gsRCG9+3gWs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=C57zkcZHNxG39QzOBfiEQ5WVx5ny025ebHd7sSzDUPiXhD27xhutnCvPaPkakmlkh EXRxTfnBntaPu//y0dnmPUBkLvyS5lUFyCrjo2uHghm3CRPSmK7aEOk0XAEkeAZUzo NHr+5yTNdNKt4C1afkELV2RPT5+Dm6jSLXJjEnbe/ox6fEz/B4NGfz7VWGzb6y+nFb RjeUDOkFjicEyfzWtqrZJSnXrEasrtFPHyZf65TXn27Kih4RmXxKcAREFvYfeB1L5H ljf/u1Er13BfgSNLEjzBe2WAEe8A2Y8IMBiX+GhzFx6BZOlhyaqTk0o5Rfr/b3eKXJ 6Uw1Q3DeDT1rA== Date: Fri, 16 May 2025 15:45:03 +0200 From: Ingo Molnar To: Dave Hansen Cc: "Kirill A. Shutemov" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Jonathan Corbet , Andy Lutomirski , Peter Zijlstra , Ard Biesheuvel , Jan Kiszka , Kieran Bingham , Michael Roth , Rick Edgecombe , Brijesh Singh , Sandipan Das , Juergen Gross , Tom Lendacky , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-efi@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCHv3 2/4] x86/64/mm: Make SPARSEMEM_VMEMMAP the only memory model Message-ID: References: <20250516123306.3812286-1-kirill.shutemov@linux.intel.com> <20250516123306.3812286-3-kirill.shutemov@linux.intel.com> <30570ca0-8da4-4ebc-84d6-0a4badfb7154@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <30570ca0-8da4-4ebc-84d6-0a4badfb7154@intel.com> X-Rspamd-Server: rspam10 X-Stat-Signature: kfxccc4mwc5pebn3jpcg3n1w34icbcce X-Rspamd-Queue-Id: 08A9320006 X-Rspam-User: X-HE-Tag: 1747403111-961075 X-HE-Meta: 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 ExNLt9cW eTDgsC5u0bNIWKs/kMGWCOGONLbhcGyQaInQsiuPQcvVIKuXuo4OjQtVwYumPp+XGD+q02raEWF8BvuTr0MMotplOF3Blr97xuuZ2q9MU8cSbq2Yk7I+FxDeLE40SQecu8yXt5hSN40kpQ/SrGkpxqH6nH7h/+RzeRVznAZjhSF0ZK+2PTSYK0vGELpnbt/YRH5ux9sl57FfnHThZ0FhoBwzb2ykEQHXFmzq4G8oLFQUHJD00l4W0mNr4Saae6Chbzsop45cNARUmV7ov03gshbzKuyhaKgHeeLjo 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: List-Subscribe: List-Unsubscribe: * Dave Hansen wrote: > On 5/16/25 05:33, Kirill A. Shutemov wrote: > > 5-level paging only supports SPARSEMEM_VMEMMAP. CONFIG_X86_5LEVEL is > > being phased out, making 5-level paging support mandatory. > > > > Make CONFIG_SPARSEMEM_VMEMMAP mandatory for x86-64 and eliminate > > any associated conditional statements. > I think we have ourselves a catch-22 here. > > SPARSEMEM_VMEMMAP was selected because the other sparsemem modes > couldn't handle a dynamic MAX_PHYS{MEM,ADDR}_BITS introduced by 5-level > paging. Now you're proposing making it static again, but keeping the > SPARSEMEM_VMEMMAP dependency. > > If you remove the dynamic MAX_PHYS{MEM,ADDR}_BITS, you should also > remove the dependency on SPARSEMEM_VMEMMAP. No? Isn't it the other way around? MAX_PHYS{MEM,ADDR}_BITS are now *always* dynamic, their value depending on whether LA57 is available and used. Thanks, Ingo