Messages in this thread | | | Date | Mon, 30 Jun 2008 10:27:37 +0530 | From | Vaidyanathan Srinivasan <> | Subject | Re: [RFC v1] Tunable sched_mc_power_savings=n |
| |
* David Collier-Brown <davecb@sun.com> [2008-06-29 14:02:58]:
> Andi Kleen <andi@firstfloor.org> said on Fri, 27 Jun 2008 00:38:53 +0200: >>> Peter Zijlstra wrote: >>>>> And your workload manager could just nice processes. It should probably >>>>> do that anyways to tell ondemand you don't need full frequency. >>>> >>>> Except that I want my nice 19 distcc processes to utilize as much cpu as >>>> possible, but just not bother any other stuff I might be doing... >>> >>> They already won't do that if you run ondemand and cpufreq. It won't >>> crank up the frequency for niced processes. > > > Tim Connors then wrote: >> Shouldn't there be a powernice, just as there is an ionice and a nice? > Hmmn, how about: > > User Commands nice(1) > > NAME > nice - invoke a command with an altered priority > > SYNOPSIS > /usr/bin/nice [-increment | -n increment] [-s|-i|-e|-p] command [argu- > ment...] > > DESCRIPTION > The nice utility invokes command, requesting that it be run > with a different priority. If -i is specified, the priority > of (disk) I/O is modified. If -e is specified, ethernet (or > other networking) priority is changed. If -p is specified, power > usage priority is changed and if -s is specified, or none of -1, > -e or -p is specified, then system scheduling priority > is modified...
This is good. We are exploring powernice. 'Generally' cpu, io and power nice values should be similar: high or low. Can we comeup with use cases where we want to have conflicting nice values for cpu, io and power?
CPU IO POWER distcc: low low low firefox: low high high ssh/shell: high high high X: high high low
I am trying to find answer to the question: Should we have the power saving tunable as 'nice' value per process or system wide?
How should we interpret the POWER parameter in a datacenter with power constraint as mentioned in this thread? Or in a simple case of AC vs battery in a laptop.
Thanks, Vaidy
| |