Interconnection network topology for large scale high performance computing (hpc) systems

Patent metadata

Field	Value
Publication number	US-2016012002-A1
Application number	US-201414486719-A
Country	US
Kind code	A1
Filing date	Sep 15, 2014
Priority date	Jul 8, 2014
Publication date	Jan 14, 2016
Grant date	—

Abstract

A multiprocessor computer system includes a plurality of processor nodes and at least a three-tier hierarchical network interconnecting the processor nodes. The hierarchical network includes a plurality of routers interconnected such that each router is connected to a subset of the plurality of processor nodes; the plurality of routers are arranged in a hierarchy of n≧3 tiers (T 1 , . . . , T n ); the plurality of routers are partitioned into disjoint groups at the first tier T 1 , the groups at tier T i being partitioned into disjoint groups (of complete T i groups) at the next tier T i+1 and a top tier T n including a single group containing all of the plurality of routers; and for all tiers 1≦i≦n, each tier-T i−1 subgroup within a tier T i group is connected by at least one link to all other tier-T i−1 subgroups within the same tier T i group.

First claim

What is claimed is:

1 . A method of constructing a multiprocessor computer system comprising:
providing a plurality of processor nodes; and coupling the plurality of processor nodes with a multi-tier hierarchical interconnection network including a plurality of routers, such that:
each router is connected to a subset of the plurality of processor nodes;
the plurality of routers are arranged in a hierarchy of n tiers (T 1 , . . . , T n ) where n is at least three;
the plurality of routers are partitioned into disjoint groups at a first tier T 1 , groups of routers at each intermediate tier T i are partitioned into disjoint groups at a next higher tier T i+1 , and a top tier T n includes a single group containing all of the plurality of routers;
for all tiers 1≦i≦n , each tier-T i−1 subgroup within a tier T i group is connected by at least one link to all other tier-T i−1 subgroups within a same tier T i group.

2 . The method of claim 1 , wherein the coupling includes connecting each group of at least one specific tier T i to each other group within a same tier T i+1 by a plurality of links, such that multiple but less than all T i−1 routers from one T i group are connected to different T i−1 routers in its peer Ti group.

3 . The method of claim 2 , wherein a number of links connecting each pair of T i subgroups is an integer divisor of the number of routers times the number of tier-i links per router in each T i subgroup.

4 . The method of claim 3 , wherein:
bundling factors at tiers (T 1 , . . . , T n ) equal (b 1 , . . . , b n ); a number of subgroups that comprise a tier T i group equals

G
i
′

=

(

∏

j
=
1

n
-
1





G
j
′

)



h
i

b
i

+
1

,

where h i is a number of peer ports per router for tier T i ;
a total number of routers S′ i that comprise a tier T i group equals

S
i
′

=

∏

j
=
1

i





G
j
′

;

and
for all i, bundling factor b i is an integer divisor of S′ i ·h i .

5 . The method of claim 1 , wherein the coupling includes coupling a number of links (h 1 , . . . , h n ) of each router to other groups at respective tiers (T 1 , T 2 , . . . , T n ), such that the number G i of subgroups that comprise a tier T i group equals

G
n

=

(

∏

j
=
1

n
-
1





G
j

)

·

h
n

+
1

and a total number S i of routers that comprise a tier T i group equals

S
i

=

(

∏

j
=
1

i





G
j

)

.

6 . The method of claim 1 , wherein a ratio between a number of links per router used to connect to groups at respective tiers (T 1 , T 2 , . . . , T n ) equals (2 n−1 , 2 n−2 , . . . , 1).

7 . The method of claim 1 , and further comprising each router providing, for each link corresponding to a connection between subgroups at tier T i , at least 2 n−i distinct virtual channels for deadlock-free shortest-path routing, for 1≦i≦n.

8 . The method of claim 7 , and further comprising:
the plurality of routers performing a virtual channel mapping of traffic arriving on an incoming virtual channel number vc x of a link corresponding to tier T x to a link corresponding to outgoing tier T y to an outgoing virtual channel number vc y depending on index x, index y, and the incoming virtual channel number vc x according to:

vc
y

=



⌊

vc
x

/

2

Assignees

• IBM

Inventors

• Arimilli Baba L
• Denzel Wolfgang
• Heidelberger Philip
• Herrera German Rodriguez
• Johnson Christopher J
• Lambrecht Lonny
• Minkenberg Cyriel
• Prisacari Bogdan

Classifications

• G06F13/4027

  using bus bridges (G06F13/4022 takes precedence) · CPC title

• G06F13/4022 Primary

  using switching circuits, e.g. switching matrix, connection or expansion network (G06F13/4009 takes precedence) · CPC title

• G06F13/4221

  being an input/output bus, e.g. ISA bus, EISA bus, PCI bus, SCSI bus · CPC title

• G06F13/4036

  and deadlock prevention · CPC title