[petsc-dev] First call to cudaMalloc or cudaFree is very slow on summit
Jeff Hammond
jeff.science at gmail.com
Sat Feb 8 14:41:29 CST 2020
Given that OLCF filesystems are the issue, have you engaged their support
personnel regarding this issue?
Jeff
On Fri, Feb 7, 2020 at 6:37 PM Junchao Zhang via petsc-dev <
petsc-dev at mcs.anl.gov> wrote:
> Have you tried passing -cuda_initialize 0 to petsc?
>
> --Junchao Zhang
>
>
> On Fri, Feb 7, 2020 at 5:16 PM Zhang, Hong via petsc-dev <
> petsc-dev at mcs.anl.gov> wrote:
>
>> I tried to install PETSc shared library in /gpfs/alpine/scratch, which
>> should be faster than the home directory. But the same overhead still
>> persists.
>>
>> Hong
>>
>> > On Feb 7, 2020, at 4:32 PM, Smith, Barry F. <bsmith at mcs.anl.gov> wrote:
>> >
>> >
>> > Perhaps the intent is that you build or install (--prefix) your
>> libraries in a different place than /autofs/nccs-svm1_home1
>> >
>> >
>> >
>> >> On Feb 7, 2020, at 3:09 PM, Zhang, Hong <hongzhang at anl.gov> wrote:
>> >>
>> >> Note that the overhead was triggered by the first call to a CUDA
>> function. So it seems that the first CUDA function triggered loading petsc
>> so (if petsc so is linked), which is slow on the summit file system.
>> >>
>> >> Hong
>> >>
>> >>> On Feb 7, 2020, at 2:54 PM, Zhang, Hong via petsc-dev <
>> petsc-dev at mcs.anl.gov> wrote:
>> >>>
>> >>> Linking any other shared library does not slow down the execution.
>> The PETSc shared library is the only one causing trouble.
>> >>>
>> >>> Here are the ldd output for two different versions. For the first
>> version, I removed -lpetsc and it ran very fast. The second (slow) version
>> was linked to petsc so.
>> >>>
>> >>> bash-4.2$ ldd ex_simple
>> >>> linux-vdso64.so.1 => (0x0000200000050000)
>> >>> liblapack.so.0 =>
>> /autofs/nccs-svm1_sw/summit/.swci/0-core/opt/spack/20180914/linux-rhel7-ppc64le/gcc-4.8.5/pgi-19.4-6acz4xyqjlpoaonjiiqjme2aknrfnzoy/linuxpower/19.4/lib/liblapack.so.0
>> (0x0000200000070000)
>> >>> libblas.so.0 =>
>> /autofs/nccs-svm1_sw/summit/.swci/0-core/opt/spack/20180914/linux-rhel7-ppc64le/gcc-4.8.5/pgi-19.4-6acz4xyqjlpoaonjiiqjme2aknrfnzoy/linuxpower/19.4/lib/libblas.so.0
>> (0x00002000009b0000)
>> >>> libhdf5hl_fortran.so.100 =>
>> /autofs/nccs-svm1_sw/summit/.swci/1-compute/opt/spack/20180914/linux-rhel7-ppc64le/pgi-19.4/hdf5-1.10.3-pgiul2yf4auv7krecd72t6vupd7e3qgn/lib/libhdf5hl_fortran.so.100
>> (0x0000200000e80000)
>> >>> libhdf5_fortran.so.100 =>
>> /autofs/nccs-svm1_sw/summit/.swci/1-compute/opt/spack/20180914/linux-rhel7-ppc64le/pgi-19.4/hdf5-1.10.3-pgiul2yf4auv7krecd72t6vupd7e3qgn/lib/libhdf5_fortran.so.100
>> (0x0000200000ed0000)
>> >>> libhdf5_hl.so.100 =>
>> /autofs/nccs-svm1_sw/summit/.swci/1-compute/opt/spack/20180914/linux-rhel7-ppc64le/pgi-19.4/hdf5-1.10.3-pgiul2yf4auv7krecd72t6vupd7e3qgn/lib/libhdf5_hl.so.100
>> (0x0000200000f50000)
>> >>> libhdf5.so.103 =>
>> /autofs/nccs-svm1_sw/summit/.swci/1-compute/opt/spack/20180914/linux-rhel7-ppc64le/pgi-19.4/hdf5-1.10.3-pgiul2yf4auv7krecd72t6vupd7e3qgn/lib/libhdf5.so.103
>> (0x0000200000fb0000)
>> >>> libX11.so.6 => /usr/lib64/libX11.so.6 (0x00002000015e0000)
>> >>> libcufft.so.10 =>
>> /sw/summit/cuda/10.1.168/lib64/libcufft.so.10 (0x0000200001770000)
>> >>> libcublas.so.10 =>
>> /sw/summit/cuda/10.1.168/lib64/libcublas.so.10 (0x0000200009b00000)
>> >>> libcudart.so.10.1 =>
>> /sw/summit/cuda/10.1.168/lib64/libcudart.so.10.1 (0x000020000d950000)
>> >>> libcusparse.so.10 =>
>> /sw/summit/cuda/10.1.168/lib64/libcusparse.so.10 (0x000020000d9f0000)
>> >>> libcusolver.so.10 =>
>> /sw/summit/cuda/10.1.168/lib64/libcusolver.so.10 (0x0000200012f50000)
>> >>> libstdc++.so.6 => /usr/lib64/libstdc++.so.6
>> (0x000020001dc40000)
>> >>> libdl.so.2 => /usr/lib64/libdl.so.2 (0x000020001ddd0000)
>> >>> libpthread.so.0 => /usr/lib64/libpthread.so.0
>> (0x000020001de00000)
>> >>> libmpiprofilesupport.so.3 =>
>> /autofs/nccs-svm1_sw/summit/.swci/1-compute/opt/spack/20180914/linux-rhel7-ppc64le/pgi-19.4/spectrum-mpi-10.3.0.1-20190611-4ymaahbai7ehhw4rves5jjiwon2laz3a/lib/libmpiprofilesupport.so.3
>> (0x000020001de40000)
>> >>> libmpi_ibm_usempi.so =>
>> /autofs/nccs-svm1_sw/summit/.swci/1-compute/opt/spack/20180914/linux-rhel7-ppc64le/pgi-19.4/spectrum-mpi-10.3.0.1-20190611-4ymaahbai7ehhw4rves5jjiwon2laz3a/lib/libmpi_ibm_usempi.so
>> (0x000020001de70000)
>> >>> libmpi_ibm_mpifh.so.3 =>
>> /autofs/nccs-svm1_sw/summit/.swci/1-compute/opt/spack/20180914/linux-rhel7-ppc64le/pgi-19.4/spectrum-mpi-10.3.0.1-20190611-4ymaahbai7ehhw4rves5jjiwon2laz3a/lib/libmpi_ibm_mpifh.so.3
>> (0x000020001dea0000)
>> >>> libmpi_ibm.so.3 =>
>> /autofs/nccs-svm1_sw/summit/.swci/1-compute/opt/spack/20180914/linux-rhel7-ppc64le/pgi-19.4/spectrum-mpi-10.3.0.1-20190611-4ymaahbai7ehhw4rves5jjiwon2laz3a/lib/libmpi_ibm.so.3
>> (0x000020001df40000)
>> >>> libpgf90rtl.so =>
>> /autofs/nccs-svm1_sw/summit/.swci/0-core/opt/spack/20180914/linux-rhel7-ppc64le/gcc-4.8.5/pgi-19.4-6acz4xyqjlpoaonjiiqjme2aknrfnzoy/linuxpower/19.4/lib/libpgf90rtl.so
>> (0x000020001e0b0000)
>> >>> libpgf90.so =>
>> /autofs/nccs-svm1_sw/summit/.swci/0-core/opt/spack/20180914/linux-rhel7-ppc64le/gcc-4.8.5/pgi-19.4-6acz4xyqjlpoaonjiiqjme2aknrfnzoy/linuxpower/19.4/lib/libpgf90.so
>> (0x000020001e0f0000)
>> >>> libpgf90_rpm1.so =>
>> /autofs/nccs-svm1_sw/summit/.swci/0-core/opt/spack/20180914/linux-rhel7-ppc64le/gcc-4.8.5/pgi-19.4-6acz4xyqjlpoaonjiiqjme2aknrfnzoy/linuxpower/19.4/lib/libpgf90_rpm1.so
>> (0x000020001e6a0000)
>> >>> libpgf902.so =>
>> /autofs/nccs-svm1_sw/summit/.swci/0-core/opt/spack/20180914/linux-rhel7-ppc64le/gcc-4.8.5/pgi-19.4-6acz4xyqjlpoaonjiiqjme2aknrfnzoy/linuxpower/19.4/lib/libpgf902.so
>> (0x000020001e6d0000)
>> >>> libpgftnrtl.so =>
>> /autofs/nccs-svm1_sw/summit/.swci/0-core/opt/spack/20180914/linux-rhel7-ppc64le/gcc-4.8.5/pgi-19.4-6acz4xyqjlpoaonjiiqjme2aknrfnzoy/linuxpower/19.4/lib/libpgftnrtl.so
>> (0x000020001e700000)
>> >>> libatomic.so.1 => /usr/lib64/libatomic.so.1
>> (0x000020001e730000)
>> >>> libpgkomp.so =>
>> /autofs/nccs-svm1_sw/summit/.swci/0-core/opt/spack/20180914/linux-rhel7-ppc64le/gcc-4.8.5/pgi-19.4-6acz4xyqjlpoaonjiiqjme2aknrfnzoy/linuxpower/19.4/lib/libpgkomp.so
>> (0x000020001e760000)
>> >>> libomp.so =>
>> /autofs/nccs-svm1_sw/summit/.swci/0-core/opt/spack/20180914/linux-rhel7-ppc64le/gcc-4.8.5/pgi-19.4-6acz4xyqjlpoaonjiiqjme2aknrfnzoy/linuxpower/19.4/lib/libomp.so
>> (0x000020001e790000)
>> >>> libomptarget.so =>
>> /autofs/nccs-svm1_sw/summit/.swci/0-core/opt/spack/20180914/linux-rhel7-ppc64le/gcc-4.8.5/pgi-19.4-6acz4xyqjlpoaonjiiqjme2aknrfnzoy/linuxpower/19.4/lib/libomptarget.so
>> (0x000020001e880000)
>> >>> libpgmath.so =>
>> /autofs/nccs-svm1_sw/summit/.swci/0-core/opt/spack/20180914/linux-rhel7-ppc64le/gcc-4.8.5/pgi-19.4-6acz4xyqjlpoaonjiiqjme2aknrfnzoy/linuxpower/19.4/lib/libpgmath.so
>> (0x000020001e8b0000)
>> >>> libpgc.so =>
>> /autofs/nccs-svm1_sw/summit/.swci/0-core/opt/spack/20180914/linux-rhel7-ppc64le/gcc-4.8.5/pgi-19.4-6acz4xyqjlpoaonjiiqjme2aknrfnzoy/linuxpower/19.4/lib/libpgc.so
>> (0x000020001e9d0000)
>> >>> librt.so.1 => /usr/lib64/librt.so.1 (0x000020001eb40000)
>> >>> libm.so.6 => /usr/lib64/libm.so.6 (0x000020001eb70000)
>> >>> libgcc_s.so.1 => /usr/lib64/libgcc_s.so.1 (0x000020001ec60000)
>> >>> libc.so.6 => /usr/lib64/libc.so.6 (0x000020001eca0000)
>> >>> libz.so.1 =>
>> /autofs/nccs-svm1_sw/summit/.swci/1-compute/opt/spack/20180914/linux-rhel7-ppc64le/pgi-19.4/zlib-1.2.11-2htm7ws4hgrthi5tyjnqxtjxgpfklxsc/lib/libz.so.1
>> (0x000020001ee90000)
>> >>> libxcb.so.1 => /usr/lib64/libxcb.so.1 (0x000020001eef0000)
>> >>> /lib64/ld64.so.2 (0x0000200000000000)
>> >>> libcublasLt.so.10 =>
>> /sw/summit/cuda/10.1.168/lib64/libcublasLt.so.10 (0x000020001ef40000)
>> >>> libutil.so.1 => /usr/lib64/libutil.so.1 (0x0000200020e50000)
>> >>> libhwloc_ompi.so.15 =>
>> /autofs/nccs-svm1_sw/summit/.swci/1-compute/opt/spack/20180914/linux-rhel7-ppc64le/pgi-19.4/spectrum-mpi-10.3.0.1-20190611-4ymaahbai7ehhw4rves5jjiwon2laz3a/lib/libhwloc_ompi.so.15
>> (0x0000200020e80000)
>> >>> libevent-2.1.so.6 =>
>> /autofs/nccs-svm1_sw/summit/.swci/1-compute/opt/spack/20180914/linux-rhel7-ppc64le/pgi-19.4/spectrum-mpi-10.3.0.1-20190611-4ymaahbai7ehhw4rves5jjiwon2laz3a/lib/libevent-2.1.so.6
>> (0x0000200020ef0000)
>> >>> libevent_pthreads-2.1.so.6 =>
>> /autofs/nccs-svm1_sw/summit/.swci/1-compute/opt/spack/20180914/linux-rhel7-ppc64le/pgi-19.4/spectrum-mpi-10.3.0.1-20190611-4ymaahbai7ehhw4rves5jjiwon2laz3a/lib/libevent_pthreads-2.1.so.6
>> (0x0000200020f70000)
>> >>> libopen-rte.so.3 =>
>> /autofs/nccs-svm1_sw/summit/.swci/1-compute/opt/spack/20180914/linux-rhel7-ppc64le/pgi-19.4/spectrum-mpi-10.3.0.1-20190611-4ymaahbai7ehhw4rves5jjiwon2laz3a/lib/libopen-rte.so.3
>> (0x0000200020fa0000)
>> >>> libopen-pal.so.3 =>
>> /autofs/nccs-svm1_sw/summit/.swci/1-compute/opt/spack/20180914/linux-rhel7-ppc64le/pgi-19.4/spectrum-mpi-10.3.0.1-20190611-4ymaahbai7ehhw4rves5jjiwon2laz3a/lib/libopen-pal.so.3
>> (0x00002000210b0000)
>> >>> libXau.so.6 => /usr/lib64/libXau.so.6 (0x00002000211a0000)
>> >>>
>> >>>
>> >>> bash-4.2$ ldd ex_simple_slow
>> >>> linux-vdso64.so.1 => (0x0000200000050000)
>> >>> libpetsc.so.3.012 =>
>> /autofs/nccs-svm1_home1/hongzh/Projects/petsc/arch-olcf-summit-sell-opt/lib/libpetsc.so.3.012
>> (0x0000200000070000)
>> >>> liblapack.so.0 =>
>> /autofs/nccs-svm1_sw/summit/.swci/0-core/opt/spack/20180914/linux-rhel7-ppc64le/gcc-4.8.5/pgi-19.4-6acz4xyqjlpoaonjiiqjme2aknrfnzoy/linuxpower/19.4/lib/liblapack.so.0
>> (0x0000200002be0000)
>> >>> libblas.so.0 =>
>> /autofs/nccs-svm1_sw/summit/.swci/0-core/opt/spack/20180914/linux-rhel7-ppc64le/gcc-4.8.5/pgi-19.4-6acz4xyqjlpoaonjiiqjme2aknrfnzoy/linuxpower/19.4/lib/libblas.so.0
>> (0x0000200003520000)
>> >>> libhdf5hl_fortran.so.100 =>
>> /autofs/nccs-svm1_sw/summit/.swci/1-compute/opt/spack/20180914/linux-rhel7-ppc64le/pgi-19.4/hdf5-1.10.3-pgiul2yf4auv7krecd72t6vupd7e3qgn/lib/libhdf5hl_fortran.so.100
>> (0x00002000039f0000)
>> >>> libhdf5_fortran.so.100 =>
>> /autofs/nccs-svm1_sw/summit/.swci/1-compute/opt/spack/20180914/linux-rhel7-ppc64le/pgi-19.4/hdf5-1.10.3-pgiul2yf4auv7krecd72t6vupd7e3qgn/lib/libhdf5_fortran.so.100
>> (0x0000200003a40000)
>> >>> libhdf5_hl.so.100 =>
>> /autofs/nccs-svm1_sw/summit/.swci/1-compute/opt/spack/20180914/linux-rhel7-ppc64le/pgi-19.4/hdf5-1.10.3-pgiul2yf4auv7krecd72t6vupd7e3qgn/lib/libhdf5_hl.so.100
>> (0x0000200003ac0000)
>> >>> libhdf5.so.103 =>
>> /autofs/nccs-svm1_sw/summit/.swci/1-compute/opt/spack/20180914/linux-rhel7-ppc64le/pgi-19.4/hdf5-1.10.3-pgiul2yf4auv7krecd72t6vupd7e3qgn/lib/libhdf5.so.103
>> (0x0000200003b20000)
>> >>> libX11.so.6 => /usr/lib64/libX11.so.6 (0x0000200004150000)
>> >>> libcufft.so.10 =>
>> /sw/summit/cuda/10.1.168/lib64/libcufft.so.10 (0x00002000042e0000)
>> >>> libcublas.so.10 =>
>> /sw/summit/cuda/10.1.168/lib64/libcublas.so.10 (0x000020000c670000)
>> >>> libcudart.so.10.1 =>
>> /sw/summit/cuda/10.1.168/lib64/libcudart.so.10.1 (0x00002000104c0000)
>> >>> libcusparse.so.10 =>
>> /sw/summit/cuda/10.1.168/lib64/libcusparse.so.10 (0x0000200010560000)
>> >>> libcusolver.so.10 =>
>> /sw/summit/cuda/10.1.168/lib64/libcusolver.so.10 (0x0000200015ac0000)
>> >>> libstdc++.so.6 => /usr/lib64/libstdc++.so.6
>> (0x00002000207b0000)
>> >>> libdl.so.2 => /usr/lib64/libdl.so.2 (0x0000200020940000)
>> >>> libpthread.so.0 => /usr/lib64/libpthread.so.0
>> (0x0000200020970000)
>> >>> libmpiprofilesupport.so.3 =>
>> /autofs/nccs-svm1_sw/summit/.swci/1-compute/opt/spack/20180914/linux-rhel7-ppc64le/pgi-19.4/spectrum-mpi-10.3.0.1-20190611-4ymaahbai7ehhw4rves5jjiwon2laz3a/lib/libmpiprofilesupport.so.3
>> (0x00002000209b0000)
>> >>> libmpi_ibm_usempi.so =>
>> /autofs/nccs-svm1_sw/summit/.swci/1-compute/opt/spack/20180914/linux-rhel7-ppc64le/pgi-19.4/spectrum-mpi-10.3.0.1-20190611-4ymaahbai7ehhw4rves5jjiwon2laz3a/lib/libmpi_ibm_usempi.so
>> (0x00002000209e0000)
>> >>> libmpi_ibm_mpifh.so.3 =>
>> /autofs/nccs-svm1_sw/summit/.swci/1-compute/opt/spack/20180914/linux-rhel7-ppc64le/pgi-19.4/spectrum-mpi-10.3.0.1-20190611-4ymaahbai7ehhw4rves5jjiwon2laz3a/lib/libmpi_ibm_mpifh.so.3
>> (0x0000200020a10000)
>> >>> libmpi_ibm.so.3 =>
>> /autofs/nccs-svm1_sw/summit/.swci/1-compute/opt/spack/20180914/linux-rhel7-ppc64le/pgi-19.4/spectrum-mpi-10.3.0.1-20190611-4ymaahbai7ehhw4rves5jjiwon2laz3a/lib/libmpi_ibm.so.3
>> (0x0000200020ab0000)
>> >>> libpgf90rtl.so =>
>> /autofs/nccs-svm1_sw/summit/.swci/0-core/opt/spack/20180914/linux-rhel7-ppc64le/gcc-4.8.5/pgi-19.4-6acz4xyqjlpoaonjiiqjme2aknrfnzoy/linuxpower/19.4/lib/libpgf90rtl.so
>> (0x0000200020c20000)
>> >>> libpgf90.so =>
>> /autofs/nccs-svm1_sw/summit/.swci/0-core/opt/spack/20180914/linux-rhel7-ppc64le/gcc-4.8.5/pgi-19.4-6acz4xyqjlpoaonjiiqjme2aknrfnzoy/linuxpower/19.4/lib/libpgf90.so
>> (0x0000200020c60000)
>> >>> libpgf90_rpm1.so =>
>> /autofs/nccs-svm1_sw/summit/.swci/0-core/opt/spack/20180914/linux-rhel7-ppc64le/gcc-4.8.5/pgi-19.4-6acz4xyqjlpoaonjiiqjme2aknrfnzoy/linuxpower/19.4/lib/libpgf90_rpm1.so
>> (0x0000200021210000)
>> >>> libpgf902.so =>
>> /autofs/nccs-svm1_sw/summit/.swci/0-core/opt/spack/20180914/linux-rhel7-ppc64le/gcc-4.8.5/pgi-19.4-6acz4xyqjlpoaonjiiqjme2aknrfnzoy/linuxpower/19.4/lib/libpgf902.so
>> (0x0000200021240000)
>> >>> libpgftnrtl.so =>
>> /autofs/nccs-svm1_sw/summit/.swci/0-core/opt/spack/20180914/linux-rhel7-ppc64le/gcc-4.8.5/pgi-19.4-6acz4xyqjlpoaonjiiqjme2aknrfnzoy/linuxpower/19.4/lib/libpgftnrtl.so
>> (0x0000200021270000)
>> >>> libatomic.so.1 => /usr/lib64/libatomic.so.1
>> (0x00002000212a0000)
>> >>> libpgkomp.so =>
>> /autofs/nccs-svm1_sw/summit/.swci/0-core/opt/spack/20180914/linux-rhel7-ppc64le/gcc-4.8.5/pgi-19.4-6acz4xyqjlpoaonjiiqjme2aknrfnzoy/linuxpower/19.4/lib/libpgkomp.so
>> (0x00002000212d0000)
>> >>> libomp.so =>
>> /autofs/nccs-svm1_sw/summit/.swci/0-core/opt/spack/20180914/linux-rhel7-ppc64le/gcc-4.8.5/pgi-19.4-6acz4xyqjlpoaonjiiqjme2aknrfnzoy/linuxpower/19.4/lib/libomp.so
>> (0x0000200021300000)
>> >>> libomptarget.so =>
>> /autofs/nccs-svm1_sw/summit/.swci/0-core/opt/spack/20180914/linux-rhel7-ppc64le/gcc-4.8.5/pgi-19.4-6acz4xyqjlpoaonjiiqjme2aknrfnzoy/linuxpower/19.4/lib/libomptarget.so
>> (0x00002000213f0000)
>> >>> libpgmath.so =>
>> /autofs/nccs-svm1_sw/summit/.swci/0-core/opt/spack/20180914/linux-rhel7-ppc64le/gcc-4.8.5/pgi-19.4-6acz4xyqjlpoaonjiiqjme2aknrfnzoy/linuxpower/19.4/lib/libpgmath.so
>> (0x0000200021420000)
>> >>> libpgc.so =>
>> /autofs/nccs-svm1_sw/summit/.swci/0-core/opt/spack/20180914/linux-rhel7-ppc64le/gcc-4.8.5/pgi-19.4-6acz4xyqjlpoaonjiiqjme2aknrfnzoy/linuxpower/19.4/lib/libpgc.so
>> (0x0000200021540000)
>> >>> librt.so.1 => /usr/lib64/librt.so.1 (0x00002000216b0000)
>> >>> libm.so.6 => /usr/lib64/libm.so.6 (0x00002000216e0000)
>> >>> libgcc_s.so.1 => /usr/lib64/libgcc_s.so.1 (0x00002000217d0000)
>> >>> libc.so.6 => /usr/lib64/libc.so.6 (0x0000200021810000)
>> >>> libz.so.1 =>
>> /autofs/nccs-svm1_sw/summit/.swci/1-compute/opt/spack/20180914/linux-rhel7-ppc64le/pgi-19.4/zlib-1.2.11-2htm7ws4hgrthi5tyjnqxtjxgpfklxsc/lib/libz.so.1
>> (0x0000200021a10000)
>> >>> libxcb.so.1 => /usr/lib64/libxcb.so.1 (0x0000200021a60000)
>> >>> /lib64/ld64.so.2 (0x0000200000000000)
>> >>> libcublasLt.so.10 =>
>> /sw/summit/cuda/10.1.168/lib64/libcublasLt.so.10 (0x0000200021ab0000)
>> >>> libutil.so.1 => /usr/lib64/libutil.so.1 (0x00002000239c0000)
>> >>> libhwloc_ompi.so.15 =>
>> /autofs/nccs-svm1_sw/summit/.swci/1-compute/opt/spack/20180914/linux-rhel7-ppc64le/pgi-19.4/spectrum-mpi-10.3.0.1-20190611-4ymaahbai7ehhw4rves5jjiwon2laz3a/lib/libhwloc_ompi.so.15
>> (0x00002000239f0000)
>> >>> libevent-2.1.so.6 =>
>> /autofs/nccs-svm1_sw/summit/.swci/1-compute/opt/spack/20180914/linux-rhel7-ppc64le/pgi-19.4/spectrum-mpi-10.3.0.1-20190611-4ymaahbai7ehhw4rves5jjiwon2laz3a/lib/libevent-2.1.so.6
>> (0x0000200023a60000)
>> >>> libevent_pthreads-2.1.so.6 =>
>> /autofs/nccs-svm1_sw/summit/.swci/1-compute/opt/spack/20180914/linux-rhel7-ppc64le/pgi-19.4/spectrum-mpi-10.3.0.1-20190611-4ymaahbai7ehhw4rves5jjiwon2laz3a/lib/libevent_pthreads-2.1.so.6
>> (0x0000200023ae0000)
>> >>> libopen-rte.so.3 =>
>> /autofs/nccs-svm1_sw/summit/.swci/1-compute/opt/spack/20180914/linux-rhel7-ppc64le/pgi-19.4/spectrum-mpi-10.3.0.1-20190611-4ymaahbai7ehhw4rves5jjiwon2laz3a/lib/libopen-rte.so.3
>> (0x0000200023b10000)
>> >>> libopen-pal.so.3 =>
>> /autofs/nccs-svm1_sw/summit/.swci/1-compute/opt/spack/20180914/linux-rhel7-ppc64le/pgi-19.4/spectrum-mpi-10.3.0.1-20190611-4ymaahbai7ehhw4rves5jjiwon2laz3a/lib/libopen-pal.so.3
>> (0x0000200023c20000)
>> >>> libXau.so.6 => /usr/lib64/libXau.so.6 (0x0000200023d10000)
>> >>>
>> >>>
>> >>>> On Feb 7, 2020, at 2:31 PM, Smith, Barry F. <bsmith at mcs.anl.gov>
>> wrote:
>> >>>>
>> >>>>
>> >>>> ldd -o on the executable of both linkings of your code.
>> >>>>
>> >>>> My guess is that without PETSc it is linking the static version of
>> the needed libraries and with PETSc the shared. And, in typical fashion,
>> the shared libraries are off on some super slow file system so take a long
>> time to be loaded and linked in on demand.
>> >>>>
>> >>>> Still a performance bug in Summit.
>> >>>>
>> >>>> Barry
>> >>>>
>> >>>>
>> >>>>> On Feb 7, 2020, at 12:23 PM, Zhang, Hong via petsc-dev <
>> petsc-dev at mcs.anl.gov> wrote:
>> >>>>>
>> >>>>> Hi all,
>> >>>>>
>> >>>>> Previously I have noticed that the first call to a CUDA function
>> such as cudaMalloc and cudaFree in PETSc takes a long time (7.5 seconds) on
>> summit. Then I prepared a simple example as attached to help OCLF reproduce
>> the problem. It turned out that the problem was caused by PETSc. The
>> 7.5-second overhead can be observed only when the PETSc lib is linked. If I
>> do not link PETSc, it runs normally. Does anyone have any idea why this
>> happens and how to fix it?
>> >>>>>
>> >>>>> Hong (Mr.)
>> >>>>>
>> >>>>> bash-4.2$ cat ex_simple.c
>> >>>>> #include <time.h>
>> >>>>> #include <cuda_runtime.h>
>> >>>>> #include <stdio.h>
>> >>>>>
>> >>>>> int main(int argc,char **args)
>> >>>>> {
>> >>>>> clock_t start,s1,s2,s3;
>> >>>>> double cputime;
>> >>>>> double *init,tmp[100] = {0};
>> >>>>>
>> >>>>> start = clock();
>> >>>>> cudaFree(0);
>> >>>>> s1 = clock();
>> >>>>> cudaMalloc((void **)&init,100*sizeof(double));
>> >>>>> s2 = clock();
>> >>>>> cudaMemcpy(init,tmp,100*sizeof(double),cudaMemcpyHostToDevice);
>> >>>>> s3 = clock();
>> >>>>> printf("free time =%lf malloc time =%lf copy time =%lf\n",((double)
>> (s1 - start)) / CLOCKS_PER_SEC,((double) (s2 - s1)) /
>> CLOCKS_PER_SEC,((double) (s3 - s2)) / CLOCKS_PER_SEC);
>> >>>>>
>> >>>>> return 0;
>> >>>>> }
>> >>>>>
>> >>>>>
>> >>>>
>> >>>
>> >>
>> >
>>
>> --
Jeff Hammond
jeff.science at gmail.com
http://jeffhammond.github.io/
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