|Summary:||RFE: nice'd 20 processes don't run unless machine is idle|
|Product:||[Retired] Red Hat Linux||Reporter:||helmut katzgraber <dummkopf>|
|Component:||kernel||Assignee:||Cristian Gafton <gafton>|
|Status:||CLOSED CURRENTRELEASE||QA Contact:|
|Fixed In Version:||Doc Type:||Bug Fix|
|Doc Text:||Story Points:||---|
|Last Closed:||1999-09-02 16:18:17 UTC||Type:||---|
|oVirt Team:||---||RHEL 7.3 requirements from Atomic Host:|
|Cloudforms Team:||---||Target Upstream Version:|
Description helmut katzgraber 1999-07-26 23:03:11 UTC
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"
Comment 1 Preston Brown 1999-08-18 17:52:59 UTC
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.
Comment 2 Jeff Johnson 1999-09-02 16:18:59 UTC
From the man page for nice: DESCRIPTION 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 19 (lowest). If you want the process to have no cpu ticks, try sending the process a SIGSTOP.
Comment 3 helmut katzgraber 1999-09-02 16:56:59 UTC
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 setiathome h.
Comment 4 Jeff Johnson 1999-09-02 20:05:59 UTC
OK, then this is a i386/sparc kernel problem.