From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f69.google.com (mail-wm0-f69.google.com [74.125.82.69]) by kanga.kvack.org (Postfix) with ESMTP id 322BA6B0033 for ; Mon, 23 Oct 2017 08:48:15 -0400 (EDT) Received: by mail-wm0-f69.google.com with SMTP id s66so2033787wmf.14 for ; Mon, 23 Oct 2017 05:48:15 -0700 (PDT) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id r30sor3379565edb.49.2017.10.23.05.48.13 for (Google Transport Security); Mon, 23 Oct 2017 05:48:13 -0700 (PDT) Date: Mon, 23 Oct 2017 15:48:11 +0300 From: "Kirill A. Shutemov" Subject: Re: [PATCH 0/6] Boot-time switching between 4- and 5-level paging for 4.15, Part 1 Message-ID: <20171023124811.4i73242s5dotnn5k@node.shutemov.name> References: <20170929140821.37654-1-kirill.shutemov@linux.intel.com> <20171003082754.no6ym45oirah53zp@node.shutemov.name> <20171017154241.f4zaxakfl7fcrdz5@node.shutemov.name> <20171020081853.lmnvaiydxhy5c63t@gmail.com> <20171020094152.skx5sh5ramq2a3vu@black.fi.intel.com> <20171020152346.f6tjybt7i5kzbhld@gmail.com> <20171020162349.3kwhdgv7qo45w4lh@node.shutemov.name> <20171023115658.geccs22o2t733np3@gmail.com> <20171023122159.wyztmsbgt5k2d4tb@node.shutemov.name> <20171023124014.mtklgmydspnvfcvg@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171023124014.mtklgmydspnvfcvg@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: Ingo Molnar Cc: "Kirill A. Shutemov" , Ingo Molnar , Linus Torvalds , x86@kernel.org, Thomas Gleixner , "H. Peter Anvin" , Andrew Morton , Andy Lutomirski , Cyrill Gorcunov , Borislav Petkov , linux-mm@kvack.org, linux-kernel@vger.kernel.org On Mon, Oct 23, 2017 at 02:40:14PM +0200, Ingo Molnar wrote: > > * Kirill A. Shutemov wrote: > > > > Making a variable that 'looks' like a constant macro dynamic in a rare Kconfig > > > scenario is asking for trouble. > > > > We expect boot-time page mode switching to be enabled in kernel of next > > generation enterprise distros. It shoudn't be that rare. > > My point remains even with not-so-rare Kconfig dependency. I don't follow how introducing new variable that depends on Kconfig option would help with the situation. We would end up with inverse situation: people would use MAX_PHYSMEM_BITS where the new variable need to be used and we will in the same situation. -- Kirill A. Shutemov -- 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