vm_try_reserve_memory_or_swap
status_t vm_try_reserve_memory_or_swap(size_t bytes, int priority, bigtime_t timeout);
if (vm_try_reserve_memory_or_swap(B_PAGE_SIZE, priority, 0) != B_OK) {
if (vm_try_reserve_memory_or_swap(swapFileSize, VM_PRIORITY_SYSTEM, 5 * 1000 * 1000) != B_OK)
if (vm_try_reserve_memory_or_swap(size - fCommittedSize, priority, 1000000)