在NDIS 5.1中Packet reuse 该怎样理解？

在WINDOWS XP 中 PtReceivePacket（）
调用里：
#ifdef NDIS51
//
// Check if we can reuse the same packet for indicating up.
// See also: PtReceive().
//

(VOID)NdisIMGetCurrentPacketStack(Packet, &Remaining);
if (Remaining)
{

//
// We can reuse \"Packet\". Indicate it up and be done with it.
//
Status = NDIS_GET_PACKET_STATUS(Packet);
NdisMIndicateReceivePacket(pAdapt->MiniportHandle, &Packet, 1);
return((Status != NDIS_STATUS_RESOURCES) ? 1 : 0);
}
#endif // NDIS51

请教：
Packet reuse 该怎样理解？

[编辑 -  6/26/02 by  hello2002]