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 <stable@xxxxxxxxxxxxxxx> know about it. >From 0bd854200873894a76f32603ff2c4c988ad6b5b5 Mon Sep 17 00:00:00 2001 From: Tang Chen <tangchen@xxxxxxxxxxxxxx> 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 <tangchen@xxxxxxxxxxxxxx> 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 <tangchen@xxxxxxxxxxxxxx> Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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 tangchen@xxxxxxxxxxxxxx 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 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html