revert "mm: fix-up zone present pages"
authorAndrew Morton <akpm@linux-foundation.org>
Fri, 16 Nov 2012 22:15:06 +0000 (14:15 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 16 Nov 2012 22:33:04 +0000 (14:33 -0800)
commit5576646f3c1abd60d72d19829de6f5d8c2ca8ecf
tree600e8d1df6536bbeb0b15b51f137d37a94f69843
parent0f3c42f522dc1ad7e27affc0a4aa8c790bce0a66
revert "mm: fix-up zone present pages"

Revert commit 7f1290f2f2a4 ("mm: fix-up zone present pages")

That patch tried to fix a issue when calculating zone->present_pages,
but it caused a regression on 32bit systems with HIGHMEM.  With that
change, reset_zone_present_pages() resets all zone->present_pages to
zero, and fixup_zone_present_pages() is called to recalculate
zone->present_pages when the boot allocator frees core memory pages into
buddy allocator.  Because highmem pages are not freed by bootmem
allocator, all highmem zones' present_pages becomes zero.

Various options for improving the situation are being discussed but for
now, let's return to the 3.6 code.

Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Petr Tesarik <ptesarik@suse.cz>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: David Rientjes <rientjes@google.com>
Tested-by: Chris Clayton <chris2553@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
arch/ia64/mm/init.c
include/linux/mm.h
mm/bootmem.c
mm/memory_hotplug.c
mm/nobootmem.c
mm/page_alloc.c