[petsc-dev] new P^1.5 algorithm in VecAssembleBegin?

[Mark Adams]

We are seeing some large times spent in VecAssemblyBegin:

VecAssemblyBegin     242 1.0 7.9796e+01 1.0 0.00e+00 0.0 0.0e+00 0.0e+00
7.3e+02 12  0  0  0  5  76  0  0  0 10     0
VecAssemblyEnd       242 1.0 5.6624e-04 2.3 0.00e+00 0.0 0.0e+00 0.0e+00
0.0e+00  0  0  0  0  0   0  0  0  0  0     0

This is with 64K cores on Edison.  On 128K cores (weak speedup) we see:

VecAssemblyBegin     248 1.0 2.3615e+02 1.0 0.00e+00 0.0 0.0e+00 0.0e+00
7.4e+02 17  0  0  0  4  87  0  0  0 10     0
VecAssemblyEnd       248 1.0 6.8855e-04 2.3 0.00e+00 0.0 0.0e+00 0.0e+00
0.0e+00  0  0  0  0  0   0  0  0  0  0     0

We are working on using older versions of PETSc to make sure this is a
PETSc issue but does anyone have any thoughts on this?

Mark
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20150528/52f01e83/attachment.html>