From: Tang Chen <tangchen@cn.fujitsu.com>
Date: Thu, 13 Nov 2014 23:19:41 +0000 (-0800)
Subject: mem-hotplug: reset node present pages when hot-adding a new pgdat
X-Git-Tag: omap-for-v3.19/fixes-for-merge-window~120^2~2
X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0bd854200873894a76f32603ff2c4c988ad6b5b5;p=pandora-kernel.git

mem-hotplug: reset node present pages when hot-adding a new 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().  Otherwise, /proc/zoneinfo will corrupt:

When the memory of node2 is offline:

  # cat /proc/zoneinfo
  ......
  Node 2, zone   Movable
  ......
        spanned  8388608
        present  8388608
        managed  0

When we online memory on node2:

  # cat /proc/zoneinfo
  ......
  Node 2, zone   Movable
  ......
        spanned  8388608
        present  16777216
        managed  8388608

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: <stable@vger.kernel.org>	[3.16+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

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