Hi Patric, The llvm openmp we compile (originally from same Intel source as we all know) seems to be Apache 2.0 licensed. Could we use that instead from a licensing standpoint?
On Wed, Dec 11, 2019 at 10:36 PM Zhao, Patric <patric.z...@intel.com> wrote: > Thanks, Sam. > > The root cause is from different OpenMP library. Intel OpenMP will provide > better performance as your data shown. > > Regarding release, since the license issue[1], we can't ship Intel OpenMP > in the binary, but the most of performance boost from MKLDNN is still > available. > I think it should be acceptable to release 1.6 with MKLDNN + GNU OpenMP > for suboptimal performance. > > To achieve the best performance, user should build from source to enable > more advanced features like Intel MKL, Intel OpenMP, AVX512. > > Thanks, > > --Patric > > [1] https://www.apache.org/legal/resolved.html#category-x > > > > > -----Original Message----- > > From: Skalicky, Sam <sska...@amazon.com.INVALID> > > Sent: Wednesday, December 11, 2019 1:36 PM > > To: dev@mxnet.incubator.apache.org > > Cc: Keshavan, Arjuna <arjun...@amazon.com>; Harish, Nihal > > <harni...@amazon.com> > > Subject: Performance regression from removing libiomp5.so > > > > Hi MXNet community, > > > > I would like to bring your attention to the performance regression that > was > > found [1] between 1.5.1 and 1.6.0 due to removing the libiomp5.so library > > due to licensing issues. This change was made since this library has a > category > > x license [2] that is not compatible with the MXNet Apache > > license/distribution. > > > > We found that using OpenBLAS instead of MKL BLAS caused a regression > > from 1500 samples/sec to 1300 samples/sec a 13.3% regression in training > > speed for a resnet18 training benchmark on a C5.18xlarge EC2 instance > (with > > 72 cores). Rebuilding with MKL BLAS showed an increase in performance to > > 1600 samples/sec in the 1.6.0 branch. > > > > Please provide your feedback on the licensing issue (are there any work- > > arounds) and the tradeoff in performance (is the benefit worth trying to > > include back into MXNet builds). > > > > Thanks to the efforts of the following folks for working on this issue > (in no > > particular order): > > Patric Zhao > > Amol Lele > > Tao Lv A > > Pedro Larroy > > Nihal Harish > > Chai Bapat > > Arjuna Keshavan > > Rong Zhang > > > > Thanks! > > Sam > > > > [1] https://github.com/apache/incubator-mxnet/issues/16891 > > [2] https://www.apache.org/legal/resolved.html#category-x >
