[petsc-users] [petsc-maint #107932] run a simple example ex19 in src/snes/examples/tutorials

[Jed Brown]

2012/3/15 Xiangze Zeng <zengshixiangze at 163.com>

> I can see log_summary output when I use -log_summary [filename].
>
> But the time of inserting the matrices values is almost the same when I
> use PCJACOBI  to run the code on GPU instead of PCSOR.They are all much
> longer than that when I run the code in CPU(I still use a small system to
> test it). The attachments are outputs of log_summary, c_jacobi_sum is the
> output of using CPU, PCJACOBI;g_sor_sum using GPU, PCSOR;g_jac_sum using
> GPU, PCJACOBI.
>

      ##########################################################
      #                                                        #
      #                          WARNING!!!                    #
      #                                                        #
      #   This code was compiled with a debugging option,      #
      #   To get timing results run ./configure                #
      #   using --with-debugging=no, the performance will      #
      #   be generally two or three times faster.              #
      #                                                        #
      ##########################################################

It's a waste of time to look at performance of a debug build, especially
when it only takes half a second.

You have probably lost preallocation information. I don't see an assembly
event, so I can't tell if that is really where the time is. (SNES makes one
automatically, you can PetscLogEventRegister(), PetscLogEventBegin/End().
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20120316/ed57d6d6/attachment.htm>