Red Hat Bugzilla – Bug 4207
RFE: nice'd 20 processes don't run unless machine is idle
Last modified: 2008-08-01 12:22:51 EDT
i looked into the kernel source and rh 6.0 i386 should
support nicelevel 20 (same information fro the man pages).
if i issue the command
renice 20 PID
it says that it reniced to 20, but when i issue ps or top i
get nicelevel 19 instead. (note that on an alpha with rh 6.0
i get the desired value of 20).
how can this problem be fixed?
nicelevel 20 != nicelevel 19. at 19 a process still gets
about 5% of CPU (competing with another process at nicelevel
0), whereas at 20 the process "sleeps"
Alan, do you have any idea why intel kernels do not permit nicelevel
20, but the alpha ones do? I'm not sure this is a bug per se, but it
is interesting at least.
From the man page for nice:
Run COMMAND with an adjusted scheduling priority. With no
COMMAND, print the current scheduling priority. ADJUST is
10 by default. Range goes from -20 (highest priority) to
If you want the process to have no cpu ticks, try sending the process
sure i can a SIGSTOP to the process, but when the CPU is idle it will
not run unless i issue a CONT. nicelevel 20 (which is a nice feature
on the alphas) instead stops the process if there is others running
and restarts it when the cpu is idle.
even though the man pages on the alpha distribution coincide with the
excerpt you sent me, i still can renice to 20:
PID USER PRI NI ....
482 dummkopf 20 20 14584 14M 1296 R N 14M 97.1 2.8 1267m
OK, then this is a i386/sparc kernel problem.