2009/2/24 STEPHANE TCHOUANMO <tchouanm at msn.com> > Dear all, > > I use petsc to solve a nonlinear convection-diffusion type equation in > porous media. > The built linear system's size is 30000 and its resolution lasts about a > hour on a single processor machine (my laptop...). > I run for that a hundred time steps and have in average 4 Newton iterations > per time step. So a hour seems huge to me with the optimized version of > Petsc. > I tryed to profile my code with the options "-log_summary" and "-info". > What i get out of it is that the first time step lasts about 15min > representing 25% of the total time and i think its not normal. > The thing is, these 15min happen at the second call of the petsc routine > "VecScatterCreate()" right after the first Newton residual. >
We can't say anything without seeing the entire output of -log_summary. Matt > > Any idea? > Thanks. > > Stephane > > <http://www.live.com/getstarted.aspx> > <http://www.microsoft.com/windows/windowslive/default.aspx> > ------------------------------ > See all the ways you can stay connected to friends and > family<http://www.microsoft.com/windows/windowslive/default.aspx> > -- 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 -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20090224/cd1ffccb/attachment.htm>
