Idle core on overloaded CPU?

[Carsten Aulbert]

Hi,

on Intel X3220 CPU based systems (4 physical cores) I came across the
following thing (Debian etch, with vanilla kernel 2.6.25.9):

starting the following:
$ screen -d -m stress -c 2
$ nice -19 screen -d -m stress -c 4

This causes two cores to be 100% busy in user state and one core to be
busy in 100% nice state. However, the remaining core is idle. Even
watching it over longer stretches of time, the situation remains static.

I guess it's a kernel misconfiguration on my part (config available here:
https://n0.aei.uni-hannover.de/linux/kernel/config-2.6.25.9-nodes
), but if not could this be a scheduling bug?

Thanks for any hint

Cheers

Carsten
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/