Messages in this thread | | | Date | Wed, 26 Aug 2009 23:08:12 +0200 | From | Ingo Molnar <> | Subject | Re: RFC: THE OFFLINE SCHEDULER |
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* Christoph Lameter <cl@linux-foundation.org> wrote:
> > to have sharp teeth nor any apparent poison fangs) - i simply > > concur with the reasons Peter listed that it is a technically > > inferior solution. > > Ok so you are saying that the reduction of OS latencies will make > the processor completely available and have no disturbances like > OFFLINE scheduling?
I'm saying that your lack of trying to reduce even low-hanging-fruit latency sources that were pointed out to you fundamentally destroys your credibility in claiming that they are unfixable for all practical purposes.
Or, to come up with a car analogy: it's a bit as if at a repair shop you complained that your car has a scratch on its cooler grid that annoys you, and you insisted that it be outfitted with a new diesel engine which needs no cooler grid (throwing away the nice Hemi block it has currently) - and ignored the mechanic's opinion that he loves the Hemi and that to him the scratch looks very much like bird-sh*t and that a proper car wash might do the trick too ;-)
> Peter has not given a solution to the problem. Nor have you.
What do you mean by 'has given a solution' - a patch?
Peter mentioned a few things that you can try to reduce the worst-case latency of the timer tick.
Peter also implemented the hr-tick solution (CONFIG_SCHED_HRTICK) - it's mostly upstream but disabled because it had problems - if you are interested in improving this area you can fix and complete it.
That would benefit ordinary Linux users too, not just rare isolation apps.
Ingo
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