On Tue, Dec 13, 2016 at 02:30:32PM -0600, Roland Haas wrote:
rhaas@login3:~/tmp$ ulimit -a | grep processes max user processes (-u) 150
which is reached (in my case) when compiling with the default -j settings in simfactory on stampede (somewhere in PeTSc).
Since I had to look it up and others might want the same: stampede is currently configured to use make -j8 which is reasonable, I believe.
And: 150 is indeed quite low. Maybe it would make sense to ask them to increase this a little if you can show that it does hamper parallel compilation.
Nevertheless, I am surprised that you reach 150 processes with just 8 parallel make sessions. Assuming you got some 'background' processes just by logging in, that would probably still mean more than 10 processes per make, which sounds high. Do you know why that number is so high?
I also compiled a lot on stampede lately. I've never seen that problem. Could it be that your limit of 150 is taken by something else than the processes spawned by make? My "problem" on stampede is the limit of 5GB home. Despite $WORK being said to be optimized for large files, they advised me to compile there if $HOME isn't big enough. 5GB is already too small for two configurations...
Frank