From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760488AbcCEAmp (ORCPT ); Fri, 4 Mar 2016 19:42:45 -0500 Received: from mga03.intel.com ([134.134.136.65]:27506 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760189AbcCEAmi (ORCPT ); Fri, 4 Mar 2016 19:42:38 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.22,538,1449561600"; d="scan'208";a="758401161" Subject: [PATCH] mm: ZONE_DEVICE depends on SPARSEMEM_VMEMMAP From: Dan Williams To: akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Vlastimil Babka Date: Fri, 04 Mar 2016 16:42:14 -0800 Message-ID: <20160305004214.12356.32017.stgit@dwillia2-desk3.jf.intel.com> User-Agent: StGit/0.17.1-9-g687f MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The primary use case for devm_memremap_pages() is to allocate an memmap array from persistent memory. That capabilty requires vmem_altmap which requires SPARSEMEM_VMEMMAP. Also, without SPARSEMEM_VMEMMAP the addition of ZONE_DEVICE expands ZONES_WIDTH and triggers the: "Unfortunate NUMA and NUMA Balancing config, growing page-frame for last_cpupid." ...warning in mm/memory.c. SPARSEMEM_VMEMMAP=n && ZONE_DEVICE=y is not a configuration we should worry about supporting. Reported-by: Vlastimil Babka Signed-off-by: Dan Williams --- mm/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/Kconfig b/mm/Kconfig index 664fa2416909..b95322ba542b 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -654,6 +654,7 @@ config ZONE_DEVICE bool "Device memory (pmem, etc...) hotplug support" if EXPERT depends on MEMORY_HOTPLUG depends on MEMORY_HOTREMOVE + depends on SPARSEMEM_VMEMMAP depends on X86_64 #arch_add_memory() comprehends device memory help