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Dear All,
I am running my Fortran 90 code in super-computing facility of our university. The max. available processor is 21, however my code is only uses 5 of them. I am using export_OMP_NUM_THREADS=20 however I dont define the stacksize after the compilation.
Would you please let me know what should I investigate to understand the problem? The below information shows that the max. number of available threads are 21 and my code only used 5 of them.
Resource usage summary: CPU time : 2471026.00 sec. Max Memory : 351 MB Average Memory : 74.98 MB Total Requested Memory : 2560.00 MB Delta Memory : 2209.00 MB Max Processes : 5 Max Threads : 21
- Tags:
- Parallel Computing
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Your system administrator may have control over limiting the maximum number of threads any one process can use.
And for any one process the OMP_NUM_THREADS can be constricted by OMP_MAX_THREADS.
The report (my guess) indicates you may be running an MPI job with 5 processes (ranks), each process/rank using 21 threads. (5 * 21 threads in use).
TimP do you have any comments on this?
Jim Dempsey
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Dear Jim, This is an openmp code not the MPI. I guess there should be difference. The administrator tells me that I can use 20 with openmp code. However as I mentioned the code only uses 5 as the report shows. The job file that I use to submit my code is:
#BSUB -J pfm
#BSUB -o pfm.o%J
#BSUB -e pfm.e%J
#BSUB -n 20
#BSUB -R "span[ptile=20]"
#BSUB -M 128
#BSUB -R 'rusage[mem=128]'
#BSUB -W 96:00
#BSUB -L /bin/bash
#BSUB -u
#### queue : ada
#
module load intel/2015A
##
ifort -openmp -o a.out huh014_thienBC.f90
##
export OMP_NUM_THREADS=20
##
export FORT_FMT_RECL=215
##
./a.out
jimdempseyatthecove wrote:
Your system administrator may have control over limiting the maximum number of threads any one process can use.
And for any one process the OMP_NUM_THREADS can be constricted by OMP_MAX_THREADS.
The report (my guess) indicates you may be running an MPI job with 5 processes (ranks), each process/rank using 21 threads. (5 * 21 threads in use).
TimP do you have any comments on this?
Jim Dempsey
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What does the following show?
CHARACER(LEN=100) :: VAL
!$OMP PARALLEL
WRITE(*,*) OMP_GET_THEAD_NUM()
!$OMP END PARALLEL
WRITE(*,*) "max threads", OMP_GET_MAX_THREADS()
WRITE(*,*) "num procs", OMP_GET_NUM_PROCS()
CALL GET_ENVIRONMENT_VARIABLE("OMP_THREAD_LIMIT",VAL)
WRITE(*,*) "OMP_THREAD_LIMIT",VAL
CALL GET_ENVIRONMENT_VARIABLE("KMP_ALL_THREADS",VAL)
WRITE(*,*) "KMP_ALL_THREADS",VAL
Jim Dempsey
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The answer is:
max threads 1 num procs 20 OMP_THREAD_LIMIT 'blank' KMP_ALL_THREADS 'blank'
jimdempseyatthecove wrote:
What does the following show?
CHARACER(LEN=100) :: VAL
!$OMP PARALLEL
WRITE(*,*) OMP_GET_THEAD_NUM()
!$OMP END PARALLEL
WRITE(*,*) "max threads", OMP_GET_MAX_THREADS()
WRITE(*,*) "num procs", OMP_GET_NUM_PROCS()
CALL GET_ENVIRONMENT_VARIABLE("OMP_THREAD_LIMIT",VAL)
WRITE(*,*) "OMP_THREAD_LIMIT",VAL
CALL GET_ENVIRONMENT_VARIABLE("KMP_ALL_THREADS",VAL)
WRITE(*,*) "KMP_ALL_THREADS",VALJim Dempsey
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I made a few edits.
Before running, set the environment variable
KMP_SETTINGS=true
This will display the OpenMP related environment variables prior to start of the main program.
Program
program NumThreads use omp_lib implicit none CHARACTER(LEN=100) :: VAL !$OMP PARALLEL !$OMP MASTER WRITE(*,*) "num threads",OMP_GET_NUM_THREADS() !$OMP END MASTER !$OMP BARRIER WRITE(*,*) OMP_GET_THREAD_NUM() !$OMP END PARALLEL WRITE(*,*) "max threads", OMP_GET_MAX_THREADS() WRITE(*,*) "num procs", OMP_GET_NUM_PROCS() CALL GET_ENVIRONMENT_VARIABLE("OMP_THREAD_LIMIT",VAL) WRITE(*,*) "OMP_THREAD_LIMIT",VAL CALL GET_ENVIRONMENT_VARIABLE("KMP_ALL_THREADS",VAL) WRITE(*,*) "KMP_ALL_THREADS",VAL end program NumThreads
Results on my system
User settings: KMP_SETTINGS=true Effective settings: KMP_ABORT_DELAY=0 KMP_ABORT_IF_NO_IRML=false KMP_ADAPTIVE_LOCK_PROPS='1,1024' KMP_ALIGN_ALLOC=64 KMP_ALL_THREADPRIVATE=128 KMP_ALL_THREADS=32768 KMP_ASAT_DEC=1 KMP_ASAT_FAVOR=0 KMP_ASAT_INC=4 KMP_ASAT_INTERVAL=5 KMP_ASAT_TRIGGER=5000 KMP_ATOMIC_MODE=1 KMP_BLOCKTIME=200 KMP_CPUINFO_FILE: value is not defined KMP_DETERMINISTIC_REDUCTION=false KMP_DUPLICATE_LIB_OK=false KMP_FORCE_REDUCTION: value is not defined KMP_FOREIGN_THREADS_THREADPRIVATE=true KMP_FORKJOIN_BARRIER='2,2' KMP_FORKJOIN_BARRIER_PATTERN='linear,linear' KMP_FORKJOIN_FRAMES=true KMP_FORKJOIN_FRAMES_MODE=3 KMP_GTID_MODE=2 KMP_HANDLE_SIGNALS=false KMP_HOT_TEAMS_MAX_LEVEL=1 KMP_HOT_TEAMS_MODE=0 KMP_INIT_AT_FORK=true KMP_INIT_WAIT=2048 KMP_ITT_PREPARE_DELAY=0 KMP_LIBRARY=throughput KMP_LOCK_KIND=queuing KMP_MALLOC_POOL_INCR=1M KMP_MONITOR_STACKSIZE: value is not defined KMP_NEXT_WAIT=1024 KMP_NUM_LOCKS_IN_BLOCK=1 KMP_PLAIN_BARRIER='2,2' KMP_PLAIN_BARRIER_PATTERN='linear,linear' KMP_REDUCTION_BARRIER='1,1' KMP_REDUCTION_BARRIER_PATTERN='hyper,hyper' KMP_SCHEDULE='static,balanced;guided,iterative' KMP_SETTINGS=true KMP_STACKOFFSET=64 KMP_STACKPAD=0 KMP_STACKSIZE=2M KMP_STORAGE_MAP=false KMP_TASKING=2 KMP_TASK_STEALING_CONSTRAINT=1 KMP_USE_IRML=false KMP_VERSION=false KMP_WARNINGS=true OMP_CANCELLATION=false OMP_DISPLAY_ENV=false OMP_DYNAMIC=false OMP_MAX_ACTIVE_LEVELS=2147483647 OMP_NESTED=false OMP_NUM_THREADS: value is not defined OMP_PLACES: value is not defined OMP_PROC_BIND='false' OMP_SCHEDULE='static' OMP_STACKSIZE=2M OMP_THREAD_LIMIT=32768 OMP_WAIT_POLICY=PASSIVE KMP_AFFINITY='noverbose,warnings,respect,granularity=core,duplicates,none' num threads 8 0 6 2 7 1 3 4 5 max threads 8 num procs 8 OMP_THREAD_LIMIT KMP_ALL_THREADS Press any key to continue . . .
Jim Dempsey
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