npages = ((end - (start & PAGE_MASK)) + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
if (npages >= 512) /* XXX arbitrary, should be tuned */
flush_tlb_all();
npages = ((end - (start & PAGE_MASK)) + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
if (npages >= 512) /* XXX arbitrary, should be tuned */
flush_tlb_all();