[petsc-users] Installation question

Matthew Knepley knepley at gmail.com
Thu May 11 07:27:19 CDT 2017


On Thu, May 11, 2017 at 7:08 AM, Pham Pham <pvsang002 at gmail.com> wrote:

> Hi Matt,
>
> Thank you for the reply.
>
> I am using University HPC which has multiple nodes, and should be good for
> parallel computing. The bad performance might be due to the way I install
> and run PETSc...
>
> Looking at the output when running streams, I can see that the Processor
> names were the same.
> Does that mean only one processor involved in computing, did it cause the
> bad performance?
>

Yes. From the data, it appears that the kind of processor you have has 12
cores, but only enough memory bandwidth to support 1.5 cores.
Try running the STREAMS with only 1 process per node. This is a setting in
your submission script, but it is different for every cluster. Thus
I would ask the local sysdamin for this machine to help you do that. You
should see almost perfect scaling with that configuration. You might
also try 2 processes per node to compare.

  Thanks,

     Matt


> Thank you very much.
>
> Ph.
>
> Below is testing output:
>
> [mpepvs at atlas5-c01 petsc-3.7.5]$ make PETSC_DIR=/home/svu/mpepvs/petsc/petsc-3.7.5
> PETSC_ARCH=arch-linux-cxx-opt streams
>
>
>
>
> cd src/benchmarks/streams; /usr/bin/gmake  --no-print-directory
> PETSC_DIR=/home/svu/mpepvs/petsc/petsc-3.7.5
> PETSC_ARCH=arch-linux-cxx-opt streams
> /app1/centos6.3/Intel/xe_2015/impi/5.0.3.048/intel64/bin/mpicxx -o
> MPIVersion.o c -wd1572 -g -O3   -fPIC    -I/home/svu/mpepvs/petsc/petsc-3.7.5/include
> -I/hom
>
>
> e/svu/mpepvs/petsc/petsc-3.7.5/arch-linux-cxx-opt/include
> -I/app1/centos6.3/Intel/xe_2015/impi/5.0.3.048/intel64/include
> `pwd`/MPIVersion.c
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> +++++++++++++++++++++++++++++++
> The version of PETSc you are using is out-of-date, we recommend updating
> to the new release
>  Available Version: 3.7.6   Installed Version: 3.7.5
> http://www.mcs.anl.gov/petsc/download/index.html
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> +++++++++++++++++++++++++++++++
> Running streams with 'mpiexec.hydra ' using 'NPMAX=12'
> Number of MPI processes 1 Processor names  atlas5-c01
> Triad:        11026.7604   Rate (MB/s)
> Number of MPI processes 2 Processor names  atlas5-c01 atlas5-c01
> Triad:        14669.6730   Rate (MB/s)
> Number of MPI processes 3 Processor names  atlas5-c01 atlas5-c01 atlas5-c01
> Triad:        12848.2644   Rate (MB/s)
> Number of MPI processes 4 Processor names  atlas5-c01 atlas5-c01
> atlas5-c01 atlas5-c01
> Triad:        15033.7687   Rate (MB/s)
> Number of MPI processes 5 Processor names  atlas5-c01 atlas5-c01
> atlas5-c01 atlas5-c01 atlas5-c01
> Triad:        13299.3830   Rate (MB/s)
> Number of MPI processes 6 Processor names  atlas5-c01 atlas5-c01
> atlas5-c01 atlas5-c01 atlas5-c01 atlas5-c01
> Triad:        14382.2116   Rate (MB/s)
> Number of MPI processes 7 Processor names  atlas5-c01 atlas5-c01
> atlas5-c01 atlas5-c01 atlas5-c01 atlas5-c01 atlas5-c01
> Triad:        13194.2573   Rate (MB/s)
> Number of MPI processes 8 Processor names  atlas5-c01 atlas5-c01
> atlas5-c01 atlas5-c01 atlas5-c01 atlas5-c01 atlas5-c01 atlas5-c01
> Triad:        14199.7255   Rate (MB/s)
> Number of MPI processes 9 Processor names  atlas5-c01 atlas5-c01
> atlas5-c01 atlas5-c01 atlas5-c01 atlas5-c01 atlas5-c01 atlas5-c01 atlas5-c01
> Triad:        13045.8946   Rate (MB/s)
> Number of MPI processes 10 Processor names  atlas5-c01 atlas5-c01
> atlas5-c01 atlas5-c01 atlas5-c01 atlas5-c01 atlas5-c01 atlas5-c01
> atlas5-c01 atlas5-c01
> Triad:        13058.3283   Rate (MB/s)
> Number of MPI processes 11 Processor names  atlas5-c01 atlas5-c01
> atlas5-c01 atlas5-c01 atlas5-c01 atlas5-c01 atlas5-c01 atlas5-c01
> atlas5-c01 atlas5-c01 atlas5-c01
> Triad:        13037.3334   Rate (MB/s)
> Number of MPI processes 12 Processor names  atlas5-c01 atlas5-c01
> atlas5-c01 atlas5-c01 atlas5-c01 atlas5-c01 atlas5-c01 atlas5-c01
> atlas5-c01 atlas5-c01 atlas5-c01 atlas5-c01
> Triad:        12526.6096   Rate (MB/s)
> ------------------------------------------------
> np  speedup
> 1 1.0
> 2 1.33
> 3 1.17
> 4 1.36
> 5 1.21
> 6 1.3
> 7 1.2
> 8 1.29
> 9 1.18
> 10 1.18
> 11 1.18
> 12 1.14
> Estimation of possible speedup of MPI programs based on Streams benchmark.
> It appears you have 1 node(s)
> See graph in the file src/benchmarks/streams/scaling.png
>
> On Fri, May 5, 2017 at 11:26 PM, Matthew Knepley <knepley at gmail.com>
> wrote:
>
>> On Fri, May 5, 2017 at 10:18 AM, Pham Pham <pvsang002 at gmail.com> wrote:
>>
>>> Hi Satish,
>>>
>>> It runs now, and shows a bad speed up:
>>> Please help to improve this.
>>>
>>
>> http://www.mcs.anl.gov/petsc/documentation/faq.html#computers
>>
>> The short answer is: You cannot improve this without buying a different
>> machine. This is
>> a fundamental algorithmic limitation that cannot be helped by threads, or
>> vectorization, or
>> anything else.
>>
>>    Matt
>>
>>
>>> Thank you.
>>>
>>>
>>>>>>
>>> On Fri, May 5, 2017 at 10:02 PM, Satish Balay <balay at mcs.anl.gov> wrote:
>>>
>>>> With Intel MPI - its best to use mpiexec.hydra [and not mpiexec]
>>>>
>>>> So you can do:
>>>>
>>>> make PETSC_DIR=/home/svu/mpepvs/petsc/petsc-3.7.5
>>>> PETSC_ARCH=arch-linux-cxx-opt MPIEXEC=mpiexec.hydra test
>>>>
>>>>
>>>> [you can also specify --with-mpiexec=mpiexec.hydra at configure time]
>>>>
>>>> Satish
>>>>
>>>>
>>>> On Fri, 5 May 2017, Pham Pham wrote:
>>>>
>>>> > *Hi,*
>>>> > *I can configure now, but fail when testing:*
>>>> >
>>>> > [mpepvs at atlas7-c10 petsc-3.7.5]$ make
>>>> > PETSC_DIR=/home/svu/mpepvs/petsc/petsc-3.7.5
>>>> PETSC_ARCH=arch-linux-cxx-opt
>>>> > test   Running test examples to verify correct installation
>>>> > Using PETSC_DIR=/home/svu/mpepvs/petsc/petsc-3.7.5 and
>>>> > PETSC_ARCH=arch-linux-cxx-opt
>>>> > Possible error running C/C++ src/snes/examples/tutorials/ex19 with 1
>>>> MPI
>>>> > process
>>>> > See http://www.mcs.anl.gov/petsc/documentation/faq.html
>>>> > mpiexec_atlas7-c10: cannot connect to local mpd
>>>> (/tmp/mpd2.console_mpepvs);
>>>> > possible causes:
>>>> >   1. no mpd is running on this host
>>>> >   2. an mpd is running but was started without a "console" (-n option)
>>>> > Possible error running C/C++ src/snes/examples/tutorials/ex19 with 2
>>>> MPI
>>>> > processes
>>>> > See http://www.mcs.anl.gov/petsc/documentation/faq.html
>>>> > mpiexec_atlas7-c10: cannot connect to local mpd
>>>> (/tmp/mpd2.console_mpepvs);
>>>> > possible causes:
>>>> >   1. no mpd is running on this host
>>>> >   2. an mpd is running but was started without a "console" (-n option)
>>>> > Possible error running Fortran example src/snes/examples/tutorials/ex
>>>> 5f
>>>> > with 1 MPI process
>>>> > See http://www.mcs.anl.gov/petsc/documentation/faq.html
>>>> > mpiexec_atlas7-c10: cannot connect to local mpd
>>>> (/tmp/mpd2.console_mpepvs);
>>>> > possible causes:
>>>> >   1. no mpd is running on this host
>>>> >   2. an mpd is running but was started without a "console" (-n option)
>>>> > Completed test examples
>>>> > =========================================
>>>> > Now to evaluate the computer systems you plan use - do:
>>>> > make PETSC_DIR=/home/svu/mpepvs/petsc/petsc-3.7.5
>>>> > PETSC_ARCH=arch-linux-cxx-opt streams
>>>> >
>>>> >
>>>> >
>>>> >
>>>> > *Please help on this.*
>>>> > *Many thanks!*
>>>> >
>>>> >
>>>> > On Thu, Apr 20, 2017 at 2:02 AM, Satish Balay <balay at mcs.anl.gov>
>>>> wrote:
>>>> >
>>>> > > Sorry - should have mentioned:
>>>> > >
>>>> > > do 'rm -rf arch-linux-cxx-opt' and rerun configure again.
>>>> > >
>>>> > > The mpich install from previous build [that is currently in
>>>> > > arch-linux-cxx-opt/]
>>>> > > is conflicting with --with-mpi-dir=/app1/centos6.3
>>>> /gnu/mvapich2-1.9/
>>>> > >
>>>> > > Satish
>>>> > >
>>>> > >
>>>> > > On Wed, 19 Apr 2017, Pham Pham wrote:
>>>> > >
>>>> > > > I reconfigured PETSs with installed MPI, however, I got serous
>>>> error:
>>>> > > >
>>>> > > > **************************ERROR*****************************
>>>> ********
>>>> > > >   Error during compile, check arch-linux-cxx-opt/lib/petsc/c
>>>> onf/make.log
>>>> > > >   Send it and arch-linux-cxx-opt/lib/petsc/conf/configure.log to
>>>> > > > petsc-maint at mcs.anl.gov
>>>> > > > ************************************************************
>>>> ********
>>>> > > >
>>>> > > > Please explain what is happening?
>>>> > > >
>>>> > > > Thank you very much.
>>>> > > >
>>>> > > >
>>>> > > >
>>>> > > >
>>>> > > > On Wed, Apr 19, 2017 at 11:43 PM, Satish Balay <balay at mcs.anl.gov
>>>> >
>>>> > > wrote:
>>>> > > >
>>>> > > > > Presumably your cluster already has a recommended MPI to use
>>>> [which is
>>>> > > > > already installed. So you should use that - instead of
>>>> > > > > --download-mpich=1
>>>> > > > >
>>>> > > > > Satish
>>>> > > > >
>>>> > > > > On Wed, 19 Apr 2017, Pham Pham wrote:
>>>> > > > >
>>>> > > > > > Hi,
>>>> > > > > >
>>>> > > > > > I just installed petsc-3.7.5 into my university cluster. When
>>>> > > evaluating
>>>> > > > > > the computer system, PETSc reports "It appears you have 1
>>>> node(s)", I
>>>> > > > > donot
>>>> > > > > > understand this, since the system is a multinodes system.
>>>> Could you
>>>> > > > > please
>>>> > > > > > explain this to me?
>>>> > > > > >
>>>> > > > > > Thank you very much.
>>>> > > > > >
>>>> > > > > > S.
>>>> > > > > >
>>>> > > > > > Output:
>>>> > > > > > =========================================
>>>> > > > > > Now to evaluate the computer systems you plan use - do:
>>>> > > > > > make PETSC_DIR=/home/svu/mpepvs/petsc/petsc-3.7.5
>>>> > > > > > PETSC_ARCH=arch-linux-cxx-opt streams
>>>> > > > > > [mpepvs at atlas7-c10 petsc-3.7.5]$ make
>>>> > > > > > PETSC_DIR=/home/svu/mpepvs/petsc/petsc-3.7.5
>>>> > > > > PETSC_ARCH=arch-linux-cxx-opt
>>>> > > > > > streams
>>>> > > > > > cd src/benchmarks/streams; /usr/bin/gmake
>>>> --no-print-directory
>>>> > > > > > PETSC_DIR=/home/svu/mpepvs/petsc/petsc-3.7.5
>>>> > > > > PETSC_ARCH=arch-linux-cxx-opt
>>>> > > > > > streams
>>>> > > > > > /home/svu/mpepvs/petsc/petsc-3.7.5/arch-linux-cxx-opt/bin/mpicxx
>>>> -o
>>>> > > > > > MPIVersion.o -c -Wall -Wwrite-strings -Wno-strict-aliasing
>>>> > > > > > -Wno-unknown-pragmas -fvisibility=hidden -g -O
>>>> > > > > > -I/home/svu/mpepvs/petsc/petsc-3.7.5/include
>>>> > > > > > -I/home/svu/mpepvs/petsc/petsc-3.7.5/arch-linux-cxx-opt/incl
>>>> ude
>>>> > > > > > `pwd`/MPIVersion.c
>>>> > > > > > Running streams with
>>>> > > > > > '/home/svu/mpepvs/petsc/petsc-3.7.5/arch-linux-cxx-opt/bin/mpiexec
>>>> '
>>>> > > > > using
>>>> > > > > > 'NPMAX=12'
>>>> > > > > > Number of MPI processes 1 Processor names  atlas7-c10
>>>> > > > > > Triad:         9137.5025   Rate (MB/s)
>>>> > > > > > Number of MPI processes 2 Processor names  atlas7-c10
>>>> atlas7-c10
>>>> > > > > > Triad:         9707.2815   Rate (MB/s)
>>>> > > > > > Number of MPI processes 3 Processor names  atlas7-c10
>>>> atlas7-c10
>>>> > > > > atlas7-c10
>>>> > > > > > Triad:        13559.5275   Rate (MB/s)
>>>> > > > > > Number of MPI processes 4 Processor names  atlas7-c10
>>>> atlas7-c10
>>>> > > > > atlas7-c10
>>>> > > > > > atlas7-c10
>>>> > > > > > Triad:        14193.0597   Rate (MB/s)
>>>> > > > > > Number of MPI processes 5 Processor names  atlas7-c10
>>>> atlas7-c10
>>>> > > > > atlas7-c10
>>>> > > > > > atlas7-c10 atlas7-c10
>>>> > > > > > Triad:        14492.9234   Rate (MB/s)
>>>> > > > > > Number of MPI processes 6 Processor names  atlas7-c10
>>>> atlas7-c10
>>>> > > > > atlas7-c10
>>>> > > > > > atlas7-c10 atlas7-c10 atlas7-c10
>>>> > > > > > Triad:        15476.5912   Rate (MB/s)
>>>> > > > > > Number of MPI processes 7 Processor names  atlas7-c10
>>>> atlas7-c10
>>>> > > > > atlas7-c10
>>>> > > > > > atlas7-c10 atlas7-c10 atlas7-c10 atlas7-c10
>>>> > > > > > Triad:        15148.7388   Rate (MB/s)
>>>> > > > > > Number of MPI processes 8 Processor names  atlas7-c10
>>>> atlas7-c10
>>>> > > > > atlas7-c10
>>>> > > > > > atlas7-c10 atlas7-c10 atlas7-c10 atlas7-c10 atlas7-c10
>>>> > > > > > Triad:        15799.1290   Rate (MB/s)
>>>> > > > > > Number of MPI processes 9 Processor names  atlas7-c10
>>>> atlas7-c10
>>>> > > > > atlas7-c10
>>>> > > > > > atlas7-c10 atlas7-c10 atlas7-c10 atlas7-c10 atlas7-c10
>>>> atlas7-c10
>>>> > > > > > Triad:        15671.3104   Rate (MB/s)
>>>> > > > > > Number of MPI processes 10 Processor names  atlas7-c10
>>>> atlas7-c10
>>>> > > > > > atlas7-c10 atlas7-c10 atlas7-c10 atlas7-c10 atlas7-c10
>>>> atlas7-c10
>>>> > > > > > atlas7-c10 atlas7-c10
>>>> > > > > > Triad:        15601.4754   Rate (MB/s)
>>>> > > > > > Number of MPI processes 11 Processor names  atlas7-c10
>>>> atlas7-c10
>>>> > > > > > atlas7-c10 atlas7-c10 atlas7-c10 atlas7-c10 atlas7-c10
>>>> atlas7-c10
>>>> > > > > > atlas7-c10 atlas7-c10 atlas7-c10
>>>> > > > > > Triad:        15434.5790   Rate (MB/s)
>>>> > > > > > Number of MPI processes 12 Processor names  atlas7-c10
>>>> atlas7-c10
>>>> > > > > > atlas7-c10 atlas7-c10 atlas7-c10 atlas7-c10 atlas7-c10
>>>> atlas7-c10
>>>> > > > > > atlas7-c10 atlas7-c10 atlas7-c10 atlas7-c10
>>>> > > > > > Triad:        15134.1263   Rate (MB/s)
>>>> > > > > > ------------------------------------------------
>>>> > > > > > np  speedup
>>>> > > > > > 1 1.0
>>>> > > > > > 2 1.06
>>>> > > > > > 3 1.48
>>>> > > > > > 4 1.55
>>>> > > > > > 5 1.59
>>>> > > > > > 6 1.69
>>>> > > > > > 7 1.66
>>>> > > > > > 8 1.73
>>>> > > > > > 9 1.72
>>>> > > > > > 10 1.71
>>>> > > > > > 11 1.69
>>>> > > > > > 12 1.66
>>>> > > > > > Estimation of possible speedup of MPI programs based on
>>>> Streams
>>>> > > > > benchmark.
>>>> > > > > > It appears you have 1 node(s)
>>>> > > > > > Unable to plot speedup to a file
>>>> > > > > > Unable to open matplotlib to plot speedup
>>>> > > > > > [mpepvs at atlas7-c10 petsc-3.7.5]$
>>>> > > > > > [mpepvs at atlas7-c10 petsc-3.7.5]$
>>>> > > > > >
>>>> > > > >
>>>> > > > >
>>>> > > >
>>>> > >
>>>> > >
>>>> >
>>>>
>>>>
>>>
>>
>>
>> --
>> What most experimenters take for granted before they begin their
>> experiments is infinitely more interesting than any results to which their
>> experiments lead.
>> -- Norbert Wiener
>>
>
>


-- 
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which their
experiments lead.
-- Norbert Wiener
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