From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f179.google.com (mail-pd0-f179.google.com [209.85.192.179]) by kanga.kvack.org (Postfix) with ESMTP id 8288B6B0105 for ; Tue, 11 Nov 2014 23:29:51 -0500 (EST) Received: by mail-pd0-f179.google.com with SMTP id g10so11354906pdj.24 for ; Tue, 11 Nov 2014 20:29:51 -0800 (PST) Received: from fgwmail6.fujitsu.co.jp (fgwmail6.fujitsu.co.jp. [192.51.44.36]) by mx.google.com with ESMTPS id aa2si21733523pad.177.2014.11.11.20.29.49 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Tue, 11 Nov 2014 20:29:50 -0800 (PST) Received: from kw-mxoi1.gw.nic.fujitsu.com (unknown [10.0.237.133]) by fgwmail6.fujitsu.co.jp (Postfix) with ESMTP id 39DB03EE0CF for ; Wed, 12 Nov 2014 13:29:48 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (s4.gw.fujitsu.co.jp [10.0.50.94]) by kw-mxoi1.gw.nic.fujitsu.com (Postfix) with ESMTP id 16DE4AC0710 for ; Wed, 12 Nov 2014 13:29:47 +0900 (JST) Received: from g01jpfmpwyt03.exch.g01.fujitsu.local (g01jpfmpwyt03.exch.g01.fujitsu.local [10.128.193.57]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 94DBC1DB8042 for ; Wed, 12 Nov 2014 13:29:46 +0900 (JST) Message-ID: <5462E200.6060405@jp.fujitsu.com> Date: Wed, 12 Nov 2014 13:28:48 +0900 From: Yasuaki Ishimatsu MIME-Version: 1.0 Subject: Re: [PATCH v2 2/2] mem-hotplug: Reset node present pages when hot-adding a new pgdat. References: <1415669227-10996-1-git-send-email-tangchen@cn.fujitsu.com> <1415669227-10996-3-git-send-email-tangchen@cn.fujitsu.com> In-Reply-To: <1415669227-10996-3-git-send-email-tangchen@cn.fujitsu.com> Content-Type: text/plain; charset="ISO-2022-JP" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Tang Chen , yinghai@kernel.org, luto@amacapital.net Cc: akpm@linux-foundation.org, santosh.shilimkar@ti.com, grygorii.strashko@ti.com, isimatu.yasuaki@jp.fujitsu.com, fabf@skynet.be, nzimmer@sgi.com, wangnan0@huawei.com, vdavydov@parallels.com, toshi.kani@hp.com, phacht@linux.vnet.ibm.com, tj@kernel.org, kirill.shutemov@linux.intel.com, riel@redhat.com, hpa@linux.intel.com, aarcange@redhat.com, qiuxishi@huawei.com, mgorman@suse.de, rientjes@google.com, hannes@cmpxchg.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, miaox@cn.fujitsu.com, stable@vger.kernel.org (2014/11/11 10:27), Tang Chen wrote: > When onlining memory on node2, node2 zoneinfo and node3 meminfo corrupted: > > # for ((i = 2048; i < 2064; i++)); do echo online_movable > /sys/devices/system/node/node2/memory$i/state; done > # cat /sys/devices/system/node/node2/meminfo > Node 2 MemTotal: 33554432 kB > Node 2 MemFree: 33549092 kB > Node 2 MemUsed: 5340 kB > ...... > # cat /sys/devices/system/node/node3/meminfo > Node 3 MemTotal: 0 kB > Node 3 MemFree: 248 kB /* corrupted, should be 0 */ > Node 3 MemUsed: 0 kB > ...... > > # cat /proc/zoneinfo > ...... > Node 2, zone Movable > ...... > spanned 8388608 > present 16777216 /* corrupted, should be 8388608 */ > managed 8388608 > > > When memory is hot-added, all the memory is in offline state. So > clear all zone->present_pages because they will be updated in > online_pages() and offline_pages(). > > Signed-off-by: Tang Chen > Reviewed-by: Yasuaki Ishimatsu I has reviewed your patch. But I have one comment. Please see below. > --- > mm/memory_hotplug.c | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index 8aba12b..26eac61 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -1067,6 +1067,14 @@ out: > } > #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ > > +static void reset_node_present_pages(pg_data_t *pgdat) > +{ > + struct zone *z; > + > + for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++) > + z->present_pages = 0; > +} You should reset pgdat->node_present_pages. pgdat->node_present_pages is set to realtotalpages by calculate_node_totalpages(). And it is also incremented/decremented by memroy online/offline. So pgdat->node_present_pages is broken internally too. Thanks, Yasuaki Ishimatsu. > + > /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ > static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start) > { > @@ -1105,6 +1113,13 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start) > */ > reset_node_managed_pages(pgdat); > > + /* > + * When memory is hot-added, all the memory is in offline state. So > + * clear all zones' present_pages because they will be updated in > + * online_pages() and offline_pages(). > + */ > + reset_node_present_pages(pgdat); > + > return pgdat; > } > > -- 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