HP-MPI Version 2.2 for HP-UX Release Note

HP-MPI V2.2 for HP-UX Release Note
What’s in This Version
12
rr Same as cyclic, but consider ldom load average.
fill Same as block, but consider ldom load average.
packed Bind all ranks to same ldom as lowest rank.
ll Bind each rank to ldoms each is currently running on.
map_ldom Schedule ranks on ldoms in cycle through MAP variable.
Three -cpu_bind options require the specification of a map/mask description. This allows for
very explicit binding of ranks to processors. The three options are map_ldom, map_cpu, and
mask_cpu.
Syntax:
-cpu_bind=[map_ldom,map_cpu,mask_cpu] [:<settings> | =<settings> | -e
MPI_BIND_MAP=<settings>]
Examples:
-cpu_bind=MAP_LDOM -e MPI_BIND_MAP=0,2,1,3
# map rank 0 to ldom 0, rank 1 to ldom 2, rank 2 to ldom1 and rank 3 to ldom 3.
-cpu_bind=MAP_LDOM=0,2,3,1
# map rank 0 to ldom 0, rank 1 to ldom 2, rank 2 to ldom 3 and rank 3 to ldom 1.
-cpu_bind=MAP_CPU:0,6,5
# map rank 0 to cpu 0, rank 1 to cpu 6, rank 2 to cpu 5.
-cpu_bind=MASK_CPU:1,4,6
# map rank 0 to cpu 0 (0001), rank 1 to cpu 2 (0100), rank 2 to cpu 1 or 2 (0110).
Environment variables for CPU binding:
• MPI_CPU_SPIN allows selection of spin value. The default is 2 seconds.
• MPI_CPU_AFFINITY is an alternative method to using -cpu_bind on the command line for
specifying binding strategy. The possible settings are LL, RANK, MAP_CPU, MASK_CPU,
LDOM, CYCLIC, BLOCK, RR, FILL, PACKED, AND MAP_LDOM.
• MPI_BIND_MAP allows specification of the integer CPU numbers, ldom numbers, or CPU
masks. These are a list of integers separated by commas (,).
A rank binding on a clustered system uses the number of ranks and the number of nodes
combined with the rank count to determine the CPU binding. Cyclic or blocked launch is
taken into account.
On a cell-based system with multiple users, the LL strategy is recommended rather than
RANK. LL allows the operating system to schedule the computational ranks. Then the
-cpu_bind capability locks the ranks to the CPU as selected by the operating system
scheduler.