• Andrew Morton's avatar
    revert "mm: fix-up zone present pages" · 5576646f
    Andrew Morton authored
    Revert commit 7f1290f2 ("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: default avatarDavid Rientjes <rientjes@google.com>
    Tested-by: default avatarChris Clayton <chris2553@googlemail.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    5576646f
memory_hotplug.c 25.3 KB