From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl0-f72.google.com (mail-pl0-f72.google.com [209.85.160.72]) by kanga.kvack.org (Postfix) with ESMTP id C937C6B0006 for ; Fri, 16 Feb 2018 12:48:52 -0500 (EST) Received: by mail-pl0-f72.google.com with SMTP id t18so2637137plo.9 for ; Fri, 16 Feb 2018 09:48:52 -0800 (PST) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id l67sor446078pfb.88.2018.02.16.09.48.51 for (Google Transport Security); Fri, 16 Feb 2018 09:48:51 -0800 (PST) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 10.3 \(3273\)) Subject: Re: [PATCH 2/3] x86/mm: introduce __PAGE_KERNEL_GLOBAL From: Nadav Amit In-Reply-To: <20180215132055.F341C31E@viggo.jf.intel.com> Date: Fri, 16 Feb 2018 09:47:49 -0800 Content-Transfer-Encoding: quoted-printable Message-Id: References: <20180215132053.6C9B48C8@viggo.jf.intel.com> <20180215132055.F341C31E@viggo.jf.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, luto@kernel.org, torvalds@linux-foundation.org, keescook@google.com, hughd@google.com, jgross@suse.com, x86@kernel.org Dave Hansen wrote: >=20 > From: Dave Hansen >=20 > Kernel mappings are historically _PAGE_GLOBAL. But, with PTI, we do = not > want them to be _PAGE_GLOBAL. We currently accomplish this by simply > clearing _PAGE_GLOBAL from the suppotred mask which ensures it is > cleansed from many of our PTE construction sites: >=20 > if (!static_cpu_has(X86_FEATURE_PTI)) > __supported_pte_mask |=3D _PAGE_GLOBAL; >=20 > But, this also means that we now get *no* opportunity to use global > pages with PTI, even for data which is shared such as the = cpu_entry_area > and entry/exit text. Doesn=E2=80=99t this patch change the kernel behavior when the = =E2=80=9Cnopti=E2=80=9D parameter is used? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org