From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755732Ab3A3P6n (ORCPT ); Wed, 30 Jan 2013 10:58:43 -0500 Received: from terminus.zytor.com ([198.137.202.10]:50900 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753868Ab3A3P6i (ORCPT ); Wed, 30 Jan 2013 10:58:38 -0500 User-Agent: K-9 Mail for Android In-Reply-To: <1359532470-28874-1-git-send-email-tangchen@cn.fujitsu.com> References: <1359532470-28874-1-git-send-email-tangchen@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: Re: [PATCH Bug fix] acpi, movablemem_map: node0 should always be unhotpluggable when using SRAT. From: "H. Peter Anvin" Date: Wed, 30 Jan 2013 07:55:11 -0800 To: Tang Chen , akpm@linux-foundation.org, jiang.liu@huawei.com, wujianguo@huawei.com, wency@cn.fujitsu.com, laijs@cn.fujitsu.com, linfeng@cn.fujitsu.com, yinghai@kernel.org, isimatu.yasuaki@jp.fujitsu.com, rob@landley.net, kosaki.motohiro@jp.fujitsu.com, minchan.kim@gmail.com, mgorman@suse.de, rientjes@google.com, guz.fnst@cn.fujitsu.com, rusty@rustcorp.com.au, lliubbo@gmail.com, jaegeuk.hanse@gmail.com, tony.luck@intel.com, glommer@parallels.com CC: linux-kernel@vger.kernel.org, linux-mm@kvack.org Message-ID: <6150ecbc-a720-4fd1-b32f-7338cc68445e@email.android.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It is not node 0, it is whatever node the kernel resides in. Tang Chen wrote: >When using movablemem_map=acpi, always set node0 as unhotpluggable, >otherwise >if all the memory is hotpluggable, the kernel will fail to boot. > >When using movablemem_map=nn[KMG]@ss[KMG], we don't stop users >specifying >node0 as hotpluggable, and ignore all the info in SRAT, so that this >option >can be used as a workaround of firmware bugs. > >Reported-by: H. Peter Anvin >Signed-off-by: Tang Chen >--- > Documentation/kernel-parameters.txt | 6 ++++++ > arch/x86/mm/srat.c | 10 ++++++++-- > 2 files changed, 14 insertions(+), 2 deletions(-) > >diff --git a/Documentation/kernel-parameters.txt >b/Documentation/kernel-parameters.txt >index 7d1b6fc..81b6f15 100644 >--- a/Documentation/kernel-parameters.txt >+++ b/Documentation/kernel-parameters.txt >@@ -1645,6 +1645,8 @@ bytes respectively. Such letter suffixes can also >be entirely omitted. > in flags from SRAT from ACPI BIOS to determine which > memory devices could be hotplugged. The corresponding > memory ranges will be set as ZONE_MOVABLE. >+ NOTE: node0 should always be unhotpluggable, otherwise >+ the kernel will fail to boot. > > movablemem_map=nn[KMG]@ss[KMG] > [KNL,X86,IA-64,PPC] This parameter is similar to >@@ -1666,6 +1668,10 @@ bytes respectively. Such letter suffixes can >also be entirely omitted. > satisfied. So the administrator should be careful that > the amount of movablemem_map areas are not too large. > Otherwise kernel won't have enough memory to start. >+ NOTE: We don't stop users specifying node0 as >+ hotpluggable, and ingore all the info in SRAT so >+ that this option can be used as a workaround of >+ firmware bugs. > > MTD_Partition= [MTD] > Format: ,,, >diff --git a/arch/x86/mm/srat.c b/arch/x86/mm/srat.c >index b20b5b7..a85d2b7 100644 >--- a/arch/x86/mm/srat.c >+++ b/arch/x86/mm/srat.c >@@ -161,9 +161,13 @@ handle_movablemem(int node, u64 start, u64 end, >u32 hotpluggable) > * > * Using movablemem_map, we can prevent memblock from allocating >memory > * on ZONE_MOVABLE at boot time. >+ * >+ * NOTE: node0 shoule always be unhotpluggable, otherwise, if all the >+ * memory is hotpluggable, there will be no memory kernel can >use. > */ > if (hotpluggable && movablemem_map.acpi) { >- insert_movablemem_map(start_pfn, end_pfn); >+ if (node != 0) >+ insert_movablemem_map(start_pfn, end_pfn); > goto out; > } > >@@ -178,7 +182,9 @@ handle_movablemem(int node, u64 start, u64 end, u32 >hotpluggable) > * Using movablemem_map, we can prevent memblock from allocating >memory > * on ZONE_MOVABLE at boot time. > * >- * NOTE: In this case, SRAT info will be ingored. >+ * NOTE: We don't stop users specifying node0 as hotpluggable, and >+ * ignore all the info in SRAT, so that this option can be used >+ * as a workaround of firmware bugs. > */ > overlap = movablemem_map_overlap(start_pfn, end_pfn); > if (overlap >= 0) { -- Sent from my mobile phone. Please excuse brevity and lack of formatting.