Red Hat Bugzilla – Bug 3670
Jobs on a Dual processor machine only use 50% of 1 CPU!!
Last modified: 2008-05-01 11:37:50 EDT
We are using an Asus P2B-D motherboard with two Pentium II
processors installed on it, and have installed RedHat 6.0
The SMP kernel is loaded by default and the two processors
seem to be detected.
However, when running a job, "top" reports only 50% CPU
usage and takes twice as long as it did beforehand.
If 2 jobs are run simultaneously, both take 50% and if 3 or
more are run, they begin to slow down each other further, so
it looks like only 1 processor is beign used, and a maximum
of 50% being allocated to any one task.
The majority of all kernel and motherboard settings are at
defaults except for simple things like drive settings and so
This issue has been forwarded to a developer for further review.
It appears this is not actually a bug but a "feature". The 50% seems
to imply 50% of both CPUS and the CPU time acts as if both CPUs were
just 1 cpu, so a job that takes 1 processor 2 minutes of real time
takes 1 minute of "CPU" time at 50%. So I guess this is not a bug.