Messages in this thread | | | Date | Fri, 04 Dec 2009 15:50:07 +0530 | From | Suresh Jayaraman <> | Subject | Re: [RFC][PATCH] sched: fix GENTLE_FAIR_SLEEPERS dependency |
| |
On 12/04/2009 03:24 PM, Ingo Molnar wrote: > > * Suresh Jayaraman <sjayaraman@suse.de> wrote: > >> The newly introduced GENTLE_FAIR_SLEEPERS does not seem to have any >> effect without FAIR_SLEEPERS. Fix sysctl.sched_features to reflect >> this. Without this change, a user who sets GENTLE_FAIR_SLEEPERS >> without FAIR_SLEEPERS would assume gentle sleeper fairness which >> is not guaranteed. >> > > There's a lot of other dependencies between scheduler features so it's > possible to change it without it having an effect on the scheduler. > > sched_features is really a development/debugging facility, you have to > know what you are doing.
I think originally introduced as a development/debugging facility, sched_features is slowly transforming into a viable tool for System Administrators, by looking at the impact of turning on/off some of these features on some workloads (especially non-desktop workloads). And I think these benefits should be passed on to the end users perhaps in the form of documentation.
> Might be worth adding a comment to the feature definition place itself > in the source - explain what it does and how it makes sense (and how it > doesnt). >
Yes it make more sense to make such changes as part of documentation than a code enforcement. I'll try and collect some of the useful tuning information.
Thanks,
-- Suresh Jayaraman
| |