Commit d702909f authored Jul 03, 2013 by Cody P Schafer Committed by Linus Torvalds Jul 03, 2013

memory_hotplug: use pgdat_resize_lock() in __offline_pages()



mmzone.h documents node_size_lock (which pgdat_resize_lock() locks) as
follows:

        * Must be held any time you expect node_start_pfn, node_present_pages
        * or node_spanned_pages stay constant.  [...]

So actually hold it when we update node_present_pages in __offline_pages().

[akpm@linux-foundation.org: fix build]
Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent aa47228a

mm/memory_hotplug.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -1492,6 +1492,7 @@ static int __ref __offline_pages(unsigned long start_pfn,
		unsigned long pfn, nr_pages, expire;
		long offlined_pages;
		int ret, drain, retry_max, node;
		unsigned long flags;
		struct zone *zone;
		struct memory_notify arg;

		@@ -1585,7 +1586,11 @@ repeat:
		/* removal success */
		zone->managed_pages -= offlined_pages;
		zone->present_pages -= offlined_pages;

		pgdat_resize_lock(zone->zone_pgdat, &flags);
		zone->zone_pgdat->node_present_pages -= offlined_pages;
		pgdat_resize_unlock(zone->zone_pgdat, &flags);

		totalram_pages -= offlined_pages;

		init_per_zone_wmark_min();

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