SPEC OMP2012 Flag Description for the Intel(R) C/C++ Compiler for IA32 and Intel 64 applications and Intel(R) Fortran Compiler for IA32 and Intel 64 applications

Copyright © 2012 Intel Corporation. All Rights Reserved.

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Optimization Flags


Portability Flags


Compiler Flags


Shell, Environment, and Other Software Settings

KMP_STACKSIZE
Specify stack size to be allocated for each thread.
KMP_AFFINITY
The value for the environment variable KMP_AFFINITY affects how the threads from an auto-parallelized program are scheduled across processors.
Specifying disabled completely disables the thread affinity interfaces. This forces the OpenMP run-time library to behave as if the affinity interface was not supported by the operating system. This includes the low-level API interfaces such as kmp_set_affinity and kmp_get_affinity, which have no effect and will return a nonzero error code.
KMP_SCHEDULE
For loops running with OpenMP schedule "static", this results in (#iterations/#threads) iterations--rounded to the next lower integer--being allocated to most threads, with at most one additional iteration being allocated to some threads. Although the largest number of iterations assigned to any thread remains the same, this results in a more even sharing of iterations between threads, which may sometimes lead to a performance improvement relative to the default static thread distribution.
OMP_DYNAMIC
OMP_DYNAMIC=[ 1 | 0 ] Enables (1) or disables (0) the dynamic adjustment of the number of threads.
OMP_NESTED
Enables (TRUE) or disables (FALSE) nested parallelism.
KMP_BLOCKTIME
Sets the time, in milliseconds, that a thread should wait, after completing the execution of a parallel region, before sleeping.
KMP_LIBRARY
Selects the OpenMP run-time library.
Set stack size to unlimited
The command "ulimit -s unlimited" is used to set the stack size limit to unlimited.