Interactive versus batch processes

Posted Dec 9, 2010 18:15 UTC (Thu) by walters (subscriber, #7396)
In reply to: Interactive versus batch processes by sync
Parent article: Group scheduling and alternatives

Okay, so figuring out the shell script usage of "chrt" was totally not obvious (the man page desperately needs examples): But so, here's the answer if you want your compile jobs to not take over the machine:

chrt --idle 0 ionice -c 3 make -j 64

Interactive versus batch processes

Posted Dec 10, 2010 14:51 UTC (Fri) by nix (subscriber, #2304) [Link] (2 responses)

-j 64 seems likely to slow your compiles down due to cache thrashing and/or simple swapping. -j (num of cores + a few) is generally recommended.

Interactive versus batch processes

Posted Dec 10, 2010 15:18 UTC (Fri) by walters (subscriber, #7396) [Link]

Right; actually, what I use is a little build tool "metabuild" here:

http://fedorapeople.org/gitweb?p=walters/public_git/homeg...

I picked a high number to emphasize the point basically, but yes, one needs to pick a good -j value.

make -j level

Posted Dec 10, 2010 20:59 UTC (Fri) by giraffedata (guest, #1954) [Link]

And if you have an exceptionally slow filesystem, also multiply by the expansion factor (single thread total time / CPU time). One one system I use, with a single CPU, I found -j6 gave minimum elapsed time.