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 E0DF5C433EF for ; Thu, 12 May 2022 13:36:34 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5CFA56B007B; Thu, 12 May 2022 09:36:34 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 57F996B007D; Thu, 12 May 2022 09:36:34 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 447268D0001; Thu, 12 May 2022 09:36:34 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 342366B007B for ; Thu, 12 May 2022 09:36:34 -0400 (EDT) Received: from smtpin13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 0605861112 for ; Thu, 12 May 2022 13:36:34 +0000 (UTC) X-FDA: 79457190708.13.1955465 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by imf28.hostedemail.com (Postfix) with ESMTP id 8F4CDC00A4 for ; Thu, 12 May 2022 13:36:12 +0000 (UTC) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1652362592; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=7LGVxfd1csrHyg3a3ARuqfO22ZbRRJvUq3doY7jKQ9c=; b=0PtyaDyLEdwKdNEmqZBly6HUlyPcXUUl7mjwtRW6N1p0cG2kNfHBRkfv712guwf01Fb9Px DZ/RauThF3XYjocUeBUe+S9pWC6F1bdc60nWiIcDUlpSEDCVgn3itdnc5/MAXpDpujo946 41Tfl6AYKE1ESSxjyqfpRiaFx+eiPt1V4V5XqR92PhYo9TiZb+pHrZZM5FUmH/5M1cxQnY KmZuY3dWLFyqnrHTWIJmVZRZEambTmXCpLcfn5xm7zQrkH1MZkRYV/8PYCX46R+JEzQldt 4bM2fDfRkoc1xILrh0XZTcmRgadFvKh2aaysWSq8sKo5rD10j557WnH82p7svw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1652362592; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=7LGVxfd1csrHyg3a3ARuqfO22ZbRRJvUq3doY7jKQ9c=; b=lDHcjCCK2ho0I/bZ1VDJrm2Tge7rsYN1+F+mxTPNZNbNYLin0MGRvODrvmVyhAww86HLOD Qbg8EGBGNc1voICQ== To: "Kirill A. Shutemov" , Dave Hansen , Andy Lutomirski , Peter Zijlstra Cc: x86@kernel.org, Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , "H . J . Lu" , Andi Kleen , Rick Edgecombe , linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: Re: [RFCv2 08/10] x86/mm: Make LAM_U48 and mappings above 47-bits mutually exclusive In-Reply-To: <20220511022751.65540-10-kirill.shutemov@linux.intel.com> References: <20220511022751.65540-1-kirill.shutemov@linux.intel.com> <20220511022751.65540-10-kirill.shutemov@linux.intel.com> Date: Thu, 12 May 2022 15:36:31 +0200 Message-ID: <875ymax480.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain Authentication-Results: imf28.hostedemail.com; dkim=pass header.d=linutronix.de header.s=2020 header.b=0PtyaDyL; dkim=pass header.d=linutronix.de header.s=2020e header.b=lDHcjCCK; spf=pass (imf28.hostedemail.com: domain of tglx@linutronix.de designates 193.142.43.55 as permitted sender) smtp.mailfrom=tglx@linutronix.de; dmarc=pass (policy=none) header.from=linutronix.de X-Rspam-User: X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 8F4CDC00A4 X-Stat-Signature: frarywy9si4zdtyomji3e7cmccc1h68x X-HE-Tag: 1652362572-314682 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, May 11 2022 at 05:27, Kirill A. Shutemov wrote: > LAM_U48 steals bits above 47-bit for tags and makes it impossible for > userspace to use full address space on 5-level paging machine. > Make these features mutually exclusive: whichever gets enabled first > blocks the othe one. So this patch prevents a mapping above 47bit when LAM48 is enabled, but I fail to spot how an already existing mapping above 47bit would prevent LAM48 from being enabled. Maybe I'm missing something which makes this magically mutually exclusive. Thanks, tglx