static __always_inline void slab_lock(struct page *page)
{
	VM_BUG_ON_PAGE(PageTail(page), page);
	bit_spin_lock(PG_locked, &page->flags);
}
static __always_inline void slab_lock(struct page *page)
{
	VM_BUG_ON_PAGE(PageTail(page), page);
	bit_spin_lock(PG_locked, &page->flags);
}