Custom Linux Kernel Scheduler issue

[Kenneth Adam Miller]

Hello,


I have a scheduler issue in two different respects:

1) I have a process that is supposed to tight loop, and it is being
given very very little time on the system. I don't want that - I want
those who would use the processor to be given the resources to run as
fast as they each can.


2) I am seeing with perf that the maximum overhead at each section
does not sum up to be more than 15 percent. Total, probably something
like 18% of cpu time is used, and my binary has rocketed in slowness
from about 2 seconds or less total to several minutes. I think that
the linux scheduler isn't scheduling it, because this process is just
some unit tests that double as benchmarks in that they shm_open a file
and write into it with memcpy's.

Can anybody help tell me what kind of linux kernel configuration could
cause this? The kernel is configured as SMP with preemption possible
as a desktop...