Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754848AbaKLE3v (ORCPT ); Tue, 11 Nov 2014 23:29:51 -0500 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:60648 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753261AbaKLE3t (ORCPT ); Tue, 11 Nov 2014 23:29:49 -0500 X-SecurityPolicyCheck: OK by SHieldMailChecker v2.0.1 X-SHieldMailCheckerPolicyVersion: FJ-ISEC-20120718-3 Message-ID: <5462E200.6060405@jp.fujitsu.com> Date: Wed, 12 Nov 2014 13:28:48 +0900 From: Yasuaki Ishimatsu User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Tang Chen , , CC: , , , , , , , , , , , , , , , , , , , , , , 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 X-SecurityPolicyCheck-GC: OK by FENCE-Mail X-TM-AS-MML: No Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@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 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/