HP-MPI Version 2.2.5 for Linux Release Note

HP-MPI V2.2.5 for Linux Release Note

What’s in This Version

a Time-out value for IBV retry if no response from target. Minimum is 1. Maximum is

31. Default is 18.

b The retry count after time-out before error is issued. Minimum is 0. Maximum is 7.

Default is 7.

c The minimum Receiver Not Ready (RNR) NAK timer. After this time, an RNR NAK

is sent back to the sender. Values: 1(0.01ms) - 31(491.52ms); 0(655.36ms). The

default is 24(40.96ms).

d RNR retry count before error is issued. Minimum is 0. Maximum is 7. Default is 7

(infinite).

e The max inline data size. Default is 128 bytes.

MPI_VAPI_QPPARAMS=a,b,c,d Specifies time-out settings for VAPI where:

a Time-out value for VAPI retry if no response from target. Minimum is 1. Maximum is

31. Default is 18.

b The retry count after time-out before error is issued. Minimum is 0. Maximum is 7.

Default is 7.

c The minimum Receiver Not Ready (RNR) NAK timer. After this time, an RNR NAK

is sent back to the sender. Values: 1(0.01ms) - 31(491.52ms); 0(655.36ms). The

default is 24(40.96ms).

d RNR retry count before error is issued. Minimum is 0. Maximum is 7. Default is 7

(infinite).

MPI_ICLIB_MX MPI_ICLIB_MX is set by the user to indicate the pathname of the MX library. It is used as

the first argument of the dlopen() call. If this environment variable is not set, then libmyriexpress.so

is used. If this fails, HP-MPI tries the absolute path /opt/mx/lib/libmyriexpress.so.

MPI RDMA Environment Variables When using InfiniBand, a certain amount of memory

is pinned. This means it is locked to physical memory and cannot be paged out. The amount of

pre-pinned memory HP-MPI uses can be adjusted using several tunables. These are described

below.

By default when the number of ranks is less than or equal to 512, each rank will pre-pin 256k

per remote rank; thus making each rank pin up to 128Mb. If the number of ranks is above 512

but less than or equal to 1024, then each rank will only pre-pin 96k per remote rank; thus

making each rank pin up to 96Mb. If the number of ranks is over 1024, then the ‘shared

receiving queue’ option is used which reduces the amount of pre-pinned memory used for each

rank to a fixed 64Mb regardless of how many ranks are used.

MPI_RDMA_MSGSIZE=a,b,c Specifies message protocol length where:

a Short message protocol threshold. If the message length is bigger than this value,

middle or long message protocol is used. The default is 16384 bytes.