On Sat, 2007-11-10 at 09:52 +1100, Nicholas Nethercote wrote: > On Sat, 3 Nov 2007, Josef Weidendorfer wrote: > > > I do not understand the benefit of QUAL above. Do I understand correctly, > > and you specify the name of an environment variable here that is substituted > > in the file name? Why can you not just say --cg-out-file=X.$QUAL (ie. the > > substitution is done by the shell at exec time)? > > It's somehow important for MPI programs, where you want every different > process's output to go to a different file. I don't know the details.
Typically with parallel applications you launch many copies of the same program with the same command line parameters, the MPI implementation itself numbers the processes from 0 to N-1 given N processes, this is known as the MPI "rank" of a process. Most job schedulers used for launching parallel jobs export the rank as a environment variable so any wrapper script, such as valgrind, can use this to name log files et al. Not having this in cachegrind frequently causes problems, I don't think cachegrind supports --log-file-exactly currently which means I can't even use a wrapper shell script to deference the variable. I have a patch somewhere to add the qualifier to the name of any core file generated, I could dig it out if you think it would help although I if possible I think it would be better so abstract all this out so all the file naming code is handled centrally and all behaves the same way. Ashley, ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Valgrind-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/valgrind-developers
