Developer Reference

  • 2021.1
  • 12/04/2020
  • Public Content
Contents

blacs_pinfo

Returns the number of processes available for use.

Syntax

call blacs_pinfo
(
mypnum
,
nprocs
)
Output Parameters
mypnum
INTEGER
. An integer between 0 and (
nprocs
- 1) that uniquely identifies each process.
nprocs
INTEGER
.The number of processes available for BLACS use.
Description
This routine is used when some initial system information is required before the BLACS are set up. On all platforms except PVM,
nprocs
is the actual number of processes available for use, that is,
nprows
*
npcols
<=
nprocs
. In PVM, the virtual machine may not have been set up before this call, and therefore no parallel machine exists. In this case,
nprocs
is returned as less than one. If a process has been spawned via the keyboard, it receives
mypnum
of 0, and all other processes get
mypnum
of -1. As a result, the user can distinguish between processes. Only after the virtual machine has been set up via a call to
BLACS_SETUP
, this routine returns the correct values for
mypnum
and
nprocs
.

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.