From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f171.google.com (mail-pf0-f171.google.com [209.85.192.171]) by kanga.kvack.org (Postfix) with ESMTP id E20D46B0254 for ; Fri, 4 Mar 2016 19:42:38 -0500 (EST) Received: by mail-pf0-f171.google.com with SMTP id 4so43927056pfd.1 for ; Fri, 04 Mar 2016 16:42:38 -0800 (PST) Received: from mga03.intel.com (mga03.intel.com. [134.134.136.65]) by mx.google.com with ESMTP id u7si9115173pfa.128.2016.03.04.16.42.38 for ; Fri, 04 Mar 2016 16:42:38 -0800 (PST) Subject: [PATCH] mm: ZONE_DEVICE depends on SPARSEMEM_VMEMMAP From: Dan Williams Date: Fri, 04 Mar 2016 16:42:14 -0800 Message-ID: <20160305004214.12356.32017.stgit@dwillia2-desk3.jf.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Vlastimil Babka 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 -- 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