Multiprocessor network multicasting and gathering
A parallel processor computer interconnect router comprises a multicasting module and a gathering module. The multicasting module is operable to receive a single incoming multicast packet comprising a destination identifier identifying a plurality of destination nodes, and to output multiple unicast packets, each of the multiple unicast packets comprising a destination header identifying a single destination node from among the plurality of destination nodes. The gathering module is operable to receive unicast reply packets from the plurality of destination nodes, and to output a combined multicast reply packet.
1 . A parallel processor computer interconnect router, the interconnect router comprising:
a multicasting module operable to receive a single incoming multicast packet comprising a destination identifier identifying a plurality of destination nodes, and to output multiple unicast packets, each of the multiple unicast packets comprising a destination header identifying a single destination node from among the plurality of destination nodes; and
a gathering module operable to receive unicast reply packets from the plurality of destination nodes, and to output a combined multicast reply packet.
2 . The parallel processor computer interconnect router of claim 1 , wherein the single incoming multicast packet comprises a cache invalidation message.
3 . The parallel processor computer interconnect router of claim 2 , wherein the unicast reply packets comprise cache invalidation acknowledge packets.
4 . The parallel processor computer interconnect router of claim 1 , wherein the output combined multicast reply packet is routed to a reply destination node designated by the single incoming multicast packet.
5 . The parallel processor computer interconnect router of claim 1 , wherein the output combined multicast reply packet is routed to a reply destination node that is a node other than the node sending the single incoming multicast packet.
6 . The parallel processor computer interconnect router of claim 1 , wherein the output combined multicast reply packet is routed to the node sending the single incoming multicast packet.
7 . The parallel processor computer interconnect router of claim 1 , wherein the router is associated with a local plurality of processors comprising a subset of processors in a parallel processor computer system, and creates multicast packets only for processors locally known to the router.
8 . The parallel processor computer interconnect router of claim 1 , wherein the gathering module comprises a gather buffer which is allocated to gather unicast reply packets if a gather buffer is available.
9 . The parallel processor computer interconnect router of claim 8 , wherein the gather buffer is allocated if available on receipt of incoming multicast packets that indicate a multicast with gather is desired.
10 . The parallel processor computer interconnect router of claim 9 , wherein incoming multicast packets that indicate a multicast with gather is desired are converted to a multicast without gather if a gather buffer cannot be allocated.
11 . A method of routing packets via a router in a parallel processing computer interconnect network, comprising:
receiving in the router an incoming multicast packet comprising a destination identifier identifying a plurality of destination nodes;
outputting from the router multiple unicast packets, each of the multiple unicast packets comprising a destination header identifying a single destination node from among the plurality of destination nodes; and
receiving in the router unicast reply packets from the plurality of destination nodes, and;
outputting from the router a combined multicast reply packet.
12 . The method of claim 11 , wherein the single incoming multicast packet comprises a cache invalidation message.
13 . The method of claim 11 , wherein the unicast reply packets comprise cache invalidation acknowledge packets.
14 . The method of claim 11 , wherein the output combined multicast reply packet is routed to a node designated by the single incoming multicast packet.
15 . The method of claim 11 , wherein the output combined multicast reply packet is routed to a reply destination node that is a node other than the node sending the single incoming multicast packet.
16 . The method of claim 11 , wherein the output combined multicast reply packet is routed to the node sending the single incoming multicast packet.
17 . The method of claim 11 , wherein the router is associated with a plurality of locally known processors comprising a subset of all processors in a parallel processor computer system, and creates multicast packets only for processors locally known to the router.
18 . The method of claim 11 , further comprising allocating a gather buffer to gather unicast reply packets if a gather buffer is available.
19 . The method of claim 18 , wherein the gather buffer is allocated if available on receipt of incoming multicast packets that indicate a multicast with gather is desired.
20 . The method of claim 19 , further comprising converting incoming multicast packets that indicate a multicast with gather is desired to a multicast without gather if a gather buffer cannot be allocated.
21 . An information handling system comprising multiple processors connected via an interconnect network and at least one router, the router comprising:
a multicasting module operable to receive a single incoming multicast packet comprising a destination identifier identifying a plurality of destination nodes, and to output multiple unicast packets, each of the multiple unicast packets comprising a destination header identifying a single destination node from among the plurality of destination nodes; and
a gathering module operable to receive unicast reply packets from the plurality of destination nodes, and to output a combined multicast reply packet.
22 . The information handling system of claim 21 , wherein the single incoming multicast packet comprises a cache invalidation message.
23 . The information handling system of claim 21 , wherein the unicast reply packets comprise cache invalidation acknowledge packets.
24 . The information handling system of claim 21 , wherein the output combined multicast reply packet is routed to a node designated by the single incoming multicast packet.
25 . The information handling system of claim 21 , wherein the output combined multicast reply packet is routed to a reply destination node that is a node other than the node sending the single incoming multicast packet.
26 . The information handling system of claim 21 , wherein the output combined multicast reply packet is routed to the node sending the single incoming multicast packet.
27 . The information handling system of claim 21 , wherein the router is associated with a locally known plurality of processors comprising a subset of all processors in a parallel processor computer system, and creates multicast packets only for processors locally known to the router.
28 . The information handling system of claim 22 , wherein the gathering module comprises a gather buffer which is allocated to gather unicast reply packets if a gather buffer is available.
29 . The information handling system of claim 28 , wherein the gather buffer is allocated if available on receipt of incoming multicast packets that indicate a multicast with gather is desired.
30 . The information handling system of claim 29 , wherein incoming multicast packets that indicate a multicast with gather is desired are converted to a multicast without gather if a gather buffer cannot be allocated.