[Radiance-general] Fun with multiple cores and rtrace

[Randolph M. Fritz]

I finally managed to get Linux going on my modelling system, an eight-core
ThinkStation.  It was running Radiance very fast.  Then I started seeing ps
output like this:

 6589 ?        S      0:00 rtrace -n 8 -h -I @sensparm.opt ot-3.oct
 6592 ?        R     29:32 rtrace -n 8 -h -I @sensparm.opt ot-3.oct
 6593 ?        R     29:32 rtrace -n 8 -h -I @sensparm.opt ot-3.oct
 6594 ?        R     29:32 rtrace -n 8 -h -I @sensparm.opt ot-3.oct
 6595 ?        R     29:32 rtrace -n 8 -h -I @sensparm.opt ot-3.oct
 6596 ?        R     29:32 rtrace -n 8 -h -I @sensparm.opt ot-3.oct
 6597 ?        R     29:32 rtrace -n 8 -h -I @sensparm.opt ot-3.oct
 6598 ?        S     41:03 rtrace -n 8 -h -I @sensparm.opt ot-3.oct
 6599 ?        S     49:48 rtrace -n 8 -h -I @sensparm.opt ot-3.oct

And it slowed down by a factor of three. My impression is that there has been an
OS glitch and it is in fact only using one core.  Anyone else seen this?

Head Debian build of Radiance, Ubuntu 10.10, most current version.

Randolph