Thanks for your reply. So, if I want to use '--with-debugging=0', what is the PETSC_ARCH equal to? I just tried to use PETSC = arch-opt, and a error message comes up: ~/petsc-dev/conf/variables:95: ~/petsc-dev/arch-opt/conf/petscvariables: No such file or directory ~l/petsc-dev/conf/rules:1018: ~/petsc-dev/arch-opt/conf/petscrules: No such file or directory make: *** No rule to make target `~l/petsc-dev/arch-opt/conf/petscrules'. Stop. this really confused me.
thanks, Alan On , Barry Smith <bsmith at mcs.anl.gov> wrote: > On Jun 3, 2011, at 2:57 PM, Alan Wei wrote: > > Dear Sir/Madam, > > Lately, I read there is a optimized version of PETSc by > using '--with-debugging=0'. I have two questions here: > > 1, Do I need to use '/config/configure.py ... --with-debugging=0' when > I configure the PETSc in order to use the non-debugging version of PETSc? > Therefore, if I want to switch PETSc between these two versions, I have > to keep configuring. > ABSOLUTELY NOT. You use two different values of the environmental > variable PETSC_ARCH and switch back and forth by changing the variable. > You can even change it on the make command line. For example make mycode > PETSC_ARCH=arch-opt > Note that you can use any name you want for the values of PETSC_ARCH. I > often use arch-debug and arch-opt to keep track of them. > > 2, I was using the '--with-debugging=0' to configure the PETSc. > However, I tested the computational rate by executing the ex29.c. The > non-debugging version does not improve the speed much; in the contrary, > it slow down the speed a little bit. The comparison is attached here. Any > idea on this. > It depends on the compiler and particular code you are running. We > recommend using the option -log_summary to see how much time is spent in > each part of the computation and how much it gets better with > optimization. > Barry > > > > thanks in advance, > > Alan > > > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20110603/a279288c/attachment.htm>
