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 83813C3ABD8 for ; Fri, 16 May 2025 15:35:32 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C88F36B01A8; Fri, 16 May 2025 11:35:29 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C77926B01AA; Fri, 16 May 2025 11:35:29 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id ABE766B01A9; Fri, 16 May 2025 11:35:29 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 890926B01A6 for ; Fri, 16 May 2025 11:35:29 -0400 (EDT) Received: from smtpin09.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 6258A1CFCC6 for ; Fri, 16 May 2025 15:35:31 +0000 (UTC) X-FDA: 83449170462.09.FE9C1A8 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf17.hostedemail.com (Postfix) with ESMTP id CD7FF4000F for ; Fri, 16 May 2025 15:35:29 +0000 (UTC) Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=GjOgxn5L; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf17.hostedemail.com: domain of mingo@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=mingo@kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1747409729; a=rsa-sha256; cv=none; b=T4mSzlh/RZdcDXP+b84ZeJsLXLAzht6Ng5ogWuArW2ngSPDlBVKjotTFLGkBMEGBXA1JCY GcOHaY42YyjfHQMTjqXzdK5F2atE6nBCBtZMlL59s+rc28QN+mH1VVAv35qduREEj30DAK u8fFFUtnVhtJiYYIV3Fihjtl0B9WOjA= ARC-Authentication-Results: i=1; imf17.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=GjOgxn5L; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf17.hostedemail.com: domain of mingo@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=mingo@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1747409729; 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=jB4v/WZkEQfBqZdXmspvZcBy4SE+cmtZlc9jEljPUs8=; b=iReuxIIg42XtBKap6mdtzXq9PR8y9El+oCMM4JzH45m9BNeatHAdoooegyqM1Fl9iTxVab 1k+OILmzayXRchGmtduJacUsUWC2wDwl2zI0bIe+LyKF7UXUFiM8y/nFeIueXWFokfR0Z8 zVgx2FFOsjdbIJMxhYGf23ZDWiwb9r4= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id EC19262A5B; Fri, 16 May 2025 15:35:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C10FFC4CEE4; Fri, 16 May 2025 15:35:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1747409728; bh=tFBuEkfpTZDqLAksOlNvQnNL7DfHD68oh+9DLHIsuks=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=GjOgxn5L6HlZB4ZnV59WnZgXYTasRydElhhX/90ByVYGKA645uJNUCcwDN1MkudLW I385G8yrdoUqBTB0XqhZqvllLe2wsxKZjeRnR4KKbO5HXWEfFyqn/4NEX62m0tqr/2 aaOKx3eiTkuC/4G20XNhpblZv3nPfyzyk3l18ZDrDVQMEFsB0/RWFkbX3F/v2Jp5Tz //XKYXg7JDq5PbYSI7NgiwkCIInbZ/e9i8+oMQqpKOd9qksPul59oxrToC359hYxXt UPGYCcJgt9BB305oJmHH+WHc/mOTeuaHgmYWMsjUit2gy5ooPaGl9bgUaj6Ya5Pojs Q03v2FKgO1BXg== Date: Fri, 16 May 2025 17:35:21 +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: X-Stat-Signature: yx5y1h88fqji61hhhrrjqcs9deuaka6i X-Rspam-User: X-Rspamd-Queue-Id: CD7FF4000F X-Rspamd-Server: rspam06 X-HE-Tag: 1747409729-791794 X-HE-Meta: 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 LuVgtLcj FPG4rksCQqd24czQBz+gkTR6zzcwbxPaIEm+VtTPXF5e+7CsEoVzD5fjJozNxhNptu1qisyvsymZqvV8Vw/SPy+HWNxirDz1kAgz1c9adPNiAAOunouOtIGFOk5iJPtPcfDH6qYc33q+Y6Uwk2mV5FZvf1nlH3S0SjmcgUsf2+Wzee0sA4bmSNGSHfpCJBHBEunKXP8MhJWX19f658rhaS3umIHefMicOlj82DvPZapYsD3x/bI3Wqu6/fjUDdqsNa/FQn2rO2+2VE7dVUPYA4dvNmz96Q5xx+4ze 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 07:08, Ingo Molnar wrote: > >> And is there any value to support !SPARSEMEM_VMEMMAP? > > Not really IMHO: > > > > .config.opensuse.default: CONFIG_SPARSEMEM_VMEMMAP_ENABLE=y > > .config.ubuntu.localinstall: CONFIG_SPARSEMEM_VMEMMAP_ENABLE=y > > .config.fedora.generic: CONFIG_SPARSEMEM_VMEMMAP_ENABLE=y > > .config.rhel.generic: CONFIG_SPARSEMEM_VMEMMAP_ENABLE=y > > I look at the distro configs all the time as well. > > But let's also not forget that none of these have lockdep turned on, Not actually true, quite a few distro debug kernel packages have lockdep on, and it's often enabled in internal QA rigs as well. Not so SPARSEMEM_VMEMMAP... > [...] and we don't want to toss out lockdep support on x86, for > example. ;) That's an apples to oranges comparison: - SPARSEMEM_VMEMMAP is always enabled, in standard and debug kernels as well. - lockdep is disabled in standard kernels, enabled in debug kernels and very much relied on. Thanks, Ingo