From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-f70.google.com (mail-oi0-f70.google.com [209.85.218.70]) by kanga.kvack.org (Postfix) with ESMTP id 666F78E0001 for ; Fri, 21 Sep 2018 07:13:30 -0400 (EDT) Received: by mail-oi0-f70.google.com with SMTP id p11-v6so11340880oih.17 for ; Fri, 21 Sep 2018 04:13:30 -0700 (PDT) Received: from foss.arm.com (foss.arm.com. [217.140.101.70]) by mx.google.com with ESMTP id f5-v6si10174020otd.396.2018.09.21.04.13.29 for ; Fri, 21 Sep 2018 04:13:29 -0700 (PDT) Date: Fri, 21 Sep 2018 12:13:25 +0100 From: Catalin Marinas Subject: Re: [PATCH] arm64: Kconfig: Remove ARCH_HAS_HOLES_MEMORYMODEL Message-ID: <20180921111324.GB238853@arrakis.emea.arm.com> References: <20180831151943.9281-1-james.morse@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180831151943.9281-1-james.morse@arm.com> Sender: owner-linux-mm@kvack.org List-ID: To: James Morse Cc: linux-arm-kernel@lists.infradead.org, Will Deacon , linux-mm@kvack.org On Fri, Aug 31, 2018 at 04:19:43PM +0100, James Morse wrote: > include/linux/mmzone.h describes ARCH_HAS_HOLES_MEMORYMODEL as > relevant when parts the memmap have been free()d. This would > happen on systems where memory is smaller than a sparsemem-section, > and the extra struct pages are expensive. pfn_valid() on these > systems returns true for the whole sparsemem-section, so an extra > memmap_valid_within() check is needed. > > On arm64 we have nomap memory, so always provide pfn_valid() to test > for nomap pages. This means ARCH_HAS_HOLES_MEMORYMODEL's extra checks > are already rolled up into pfn_valid(). > > Remove it. > > Signed-off-by: James Morse Queued for 4.20. Thanks. -- Catalin