On Fri, Jun 3, 2011 at 3:28 PM, <span dir="ltr"><<a href="mailto:zhenglun.wei@gmail.com">zhenglun.wei@gmail.com</a>></span> wrote:<br><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
Thanks for your reply. <br> So, if I want to use '--with-debugging=0', what is the PETSC_ARCH equal to?<br></blockquote><div><br></div><div>When you run configure, at the end it prints out a LARGE message that indicates</div>
<div><br></div><div> - What PETSC_ARCH it has chosen</div><div><br></div><div> - Exactly the command line to run when building</div><div><br></div><div>This information is also stored in configure.log</div><div> </div><div>
Matt</div><div><br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"> I just tried to use PETSC = arch-opt, and a error message comes up: <br>~/petsc-dev/conf/variables:95: ~/petsc-dev/arch-opt/conf/petscvariables: No such file or directory<br>
~l/petsc-dev/conf/rules:1018: ~/petsc-dev/arch-opt/conf/petscrules: No such file or directory<br>make: *** No rule to make target `~l/petsc-dev/arch-opt/conf/petscrules'. Stop.<br> this really confused me.<br><br>
thanks,<br>Alan<br><br>On , Barry Smith <<a href="mailto:bsmith@mcs.anl.gov" target="_blank">bsmith@mcs.anl.gov</a>> wrote:<br>> <br>> <br>> On Jun 3, 2011, at 2:57 PM, Alan Wei wrote:<br>> <br>> <br>
> <br>> > Dear Sir/Madam,<br>> <br>> > Lately, I read there is a optimized version of PETSc by using '--with-debugging=0'. I have two questions here:<br>> <br>> > 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.<br>
> <br>> <br>> <br>> <br>> <br>> 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<br>
> <br>> <br>> <br>> 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.<br>> <br>> <br>> <br>> <br>> <br>> > 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.<br>
> <br>> <br>> <br>> 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.<br>
> <br>> <br>> <br>> <br>> <br>> Barry<br>> <br>> <br>> <br>> <br>> <br>> ><br>> <br>> > thanks in advance,<br>> <br>> > Alan<br>> <br>> ><br>> <br>> > <br>
> <br>> <br>> <br>></blockquote></div><br><br clear="all"><br>-- <br>What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>
-- Norbert Wiener<br>