Re: [ckrm-tech] [RFC 0/4] sched: Add CPU rate caps (improved)

[Peter Williams]

MAEDA Naoaki wrote:
> Peter Williams wrote:
> > I've done some informal testing with smaller values of CAP_STATS_OFFSET 
> > and there is only a minor improvement.
> >
> > However, something that does improve behaviour for short lived tasks is 
> > to increase the value of HZ.  This is because the basic unit of CPU
> > allocation by the scheduler is 1/HZ and this is also the minimum time 
> > (and granularity) with which sinbinning and other capping measures can 
> > be implemented.  This is the fundamental limiting factor for the 
> > accuracy of capping i.e. if everything worked perfectly the best 
> > granularity that can be expected from capping of short lived tasks is 
> > 1000 / (HZ * duration) where duration is in seconds.
>
> I already defines CONFIG_HZ=1000. Do you suggest increasing more?

No.

Peter
--
Dr Peter Williams, Chief Scientist         <peterw@xxxxxxxxxx>
Aurema Pty Limited
Level 2, 130 Elizabeth St, Sydney, NSW 2000, Australia
Tel:+61 2 9698 2322  Fax:+61 2 9699 9174 http://www.aurema.com
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/