MAX_ORDER is not inclusive: the maximum allocation order buddy allocator can deliver is MAX_ORDER-1. Fix MAX_ORDER usage in linux_main(). Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Richard Weinberger <richard@xxxxxx> Cc: Anton Ivanov <anton.ivanov@xxxxxxxxxxxxxxxxxx> Cc: Johannes Berg <johannes@xxxxxxxxxxxxxxxx> --- arch/um/kernel/um_arch.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c index 8dcda617b8bf..5e5a9c8e0e5d 100644 --- a/arch/um/kernel/um_arch.c +++ b/arch/um/kernel/um_arch.c @@ -368,10 +368,10 @@ int __init linux_main(int argc, char **argv) max_physmem = TASK_SIZE - uml_physmem - iomem_size - MIN_VMALLOC; /* - * Zones have to begin on a 1 << MAX_ORDER page boundary, + * Zones have to begin on a 1 << MAX_ORDER-1 page boundary, * so this makes sure that's true for highmem */ - max_physmem &= ~((1 << (PAGE_SHIFT + MAX_ORDER)) - 1); + max_physmem &= ~((1 << (PAGE_SHIFT + MAX_ORDER - 1)) - 1); if (physmem_size + iomem_size > max_physmem) { highmem = physmem_size + iomem_size - max_physmem; physmem_size -= highmem; -- 2.39.2