Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753361Ab3EZOaE (ORCPT ); Sun, 26 May 2013 10:30:04 -0400 Received: from mail-pa0-f41.google.com ([209.85.220.41]:46167 "EHLO mail-pa0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752923Ab3EZOaD (ORCPT ); Sun, 26 May 2013 10:30:03 -0400 Message-ID: <51A21C63.4010606@gmail.com> Date: Sun, 26 May 2013 22:29:55 +0800 From: Liu Jiang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130404 Thunderbird/17.0.5 MIME-Version: 1.0 To: KOSAKI Motohiro CC: Wanpeng Li , Andrew Morton , Michal Hocko , KAMEZAWA Hiroyuki , David Rientjes , Jiang Liu , Tang Chen , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Benjamin Herrenschmidt Subject: Re: [PATCH v2 1/4] mm/memory-hotplug: fix lowmem count overflow when offline pages References: <1369298568-20094-1-git-send-email-liwanp@linux.vnet.ibm.com> <51A16268.4000401@gmail.com> In-Reply-To: <51A16268.4000401@gmail.com> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1573 Lines: 43 On 05/26/2013 09:16 AM, KOSAKI Motohiro wrote: >> --- >> mm/page_alloc.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/mm/page_alloc.c b/mm/page_alloc.c >> index 98cbdf6..23b921f 100644 >> --- a/mm/page_alloc.c >> +++ b/mm/page_alloc.c >> @@ -6140,6 +6140,8 @@ __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) >> list_del(&page->lru); >> rmv_page_order(page); >> zone->free_area[order].nr_free--; >> + if (PageHighMem(page)) >> + totalhigh_pages -= 1 << order; >> for (i = 0; i < (1 << order); i++) >> SetPageReserved((page+i)); >> pfn += (1 << order); > > memory hotplug don't support 32bit since it was born, at least, when the system has highmem. > Why can't we disable memory hotremove when 32bit at compile time? Hi KOSAKI, Could you please help to give more information on the background about why 32bit platforms with highmem can't support memory hot-removal? We are trying to enable memory hot-removal on some 32bit platforms with highmem, really appreciate your help here! Thanks! Gerry > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/