This is a note to let you know that I've just added the patch titled

    mem-hotplug: reset node present pages when hot-adding a new pgdat

to the 3.17-stable tree which can be found at:
    
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     mem-hotplug-reset-node-present-pages-when-hot-adding-a-new-pgdat.patch
and it can be found in the queue-3.17 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.


>From 0bd854200873894a76f32603ff2c4c988ad6b5b5 Mon Sep 17 00:00:00 2001
From: Tang Chen <[email protected]>
Date: Thu, 13 Nov 2014 15:19:41 -0800
Subject: mem-hotplug: reset node present pages when hot-adding a new pgdat

From: Tang Chen <[email protected]>

commit 0bd854200873894a76f32603ff2c4c988ad6b5b5 upstream.

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 <[email protected]>
Reviewed-by: Yasuaki Ishimatsu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 mm/memory_hotplug.c |   17 +++++++++++++++++
 1 file changed, 17 insertions(+)

--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1067,6 +1067,16 @@ 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;
+
+       pgdat->node_present_pages = 0;
+}
+
 /* 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 +1115,13 @@ static pg_data_t __ref *hotadd_new_pgdat
         */
        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;
 }
 


Patches currently in stable-queue which might be from [email protected] 
are

queue-3.17/mm-page_alloc-restrict-max-order-of-merging-on-isolated-pageblock.patch
queue-3.17/mem-hotplug-reset-node-present-pages-when-hot-adding-a-new-pgdat.patch
queue-3.17/mm-page_alloc-fix-incorrect-isolation-behavior-by-rechecking-migratetype.patch
queue-3.17/mem-hotplug-reset-node-managed-pages-when-hot-adding-a-new-pgdat.patch
queue-3.17/mm-page_alloc-move-freepage-counting-logic-to-__free_one_page.patch
queue-3.17/mm-page_alloc-add-freepage-on-isolate-pageblock-to-correct-buddy-list.patch
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