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=-10.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 057CDC49ED7 for ; Fri, 13 Sep 2019 09:55:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D41E120717 for ; Fri, 13 Sep 2019 09:55:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387880AbfIMJzM (ORCPT ); Fri, 13 Sep 2019 05:55:12 -0400 Received: from mga06.intel.com ([134.134.136.31]:11019 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387439AbfIMJzM (ORCPT ); Fri, 13 Sep 2019 05:55:12 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 13 Sep 2019 02:55:12 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,489,1559545200"; d="scan'208";a="336850934" Received: from black.fi.intel.com ([10.237.72.28]) by orsmga004.jf.intel.com with ESMTP; 13 Sep 2019 02:55:09 -0700 Received: by black.fi.intel.com (Postfix, from userid 1000) id 5317DF3; Fri, 13 Sep 2019 12:55:08 +0300 (EEST) From: "Kirill A. Shutemov" To: Linus Torvalds , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" Cc: Dave Hansen , Andy Lutomirski , Peter Zijlstra , x86@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: [PATCH] x86/mm: Enable 5-level paging support by default Date: Fri, 13 Sep 2019 12:54:52 +0300 Message-Id: <20190913095452.40592-1-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.23.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Support of boot-time switching between 4- and 5-level paging mode is upstream since 4.17. We run internal testing with 5-level paging support enabled for a while and it doesn't not cause any functional or performance regression on 4-level paging hardware. The only 5-level paging related regressions I saw were in early boot code that runs independently from CONFIG_X86_5LEVEL. The next major release of distributions expected to have CONFIG_X86_5LEVEL=y. Enable the option by default. It may help to catch obscure bugs early. Signed-off-by: Kirill A. Shutemov --- arch/x86/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 222855cc0158..2f7cb91d850e 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1483,6 +1483,7 @@ config X86_PAE config X86_5LEVEL bool "Enable 5-level page tables support" + default y select DYNAMIC_MEMORY_LAYOUT select SPARSEMEM_VMEMMAP depends on X86_64 -- 2.21.0