Patch fixes a boot crash with pagealloc debugging enabled:
Initializing HighMem for node 0 (000377fe:0003fff0)
BUG: unable to handle kernel paging request at f6fefe80
IP: [<c1621ab5>] find_range_array+0x5e/0x69
[...]
Call Trace:
[<c1622064>] __get_free_all_memory_range+0x39/0xb4
[<c1620dd0>] add_highpages_with_active_regions+0x18/0x9b
[<c1621a2e>] set_highmem_pages_init+0x70/0x90
[<c162122b>] mem_init+0x50/0x21b
[<c16155bd>] start_kernel+0x1bf/0x31c
[<c1615065>] i386_start_kernel+0x65/0x67
The crash happens when memblock wants to allocate big area for
temporary "struct range" array and reuses pages from top of low
memory, which were already passed to the buddy allocator.
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: linux-mm@kvack.org
Cc: Mel Gorman <mgorman@suse.de>
Link: http://lkml.kernel.org/r/20111206080833.GB3105@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
855c743a27