Re: [PATCH] xen/sched_credit: Use delay to control scheduling frequency

[Dario Faggioli <raistlin@linux.it>]

[-- Attachment #1.1: Type: text/plain, Size: 1415 bytes --]

On Tue, 2011-12-20 at 10:26 +0000, George Dunlap wrote: 
> > I think that too, but maybe you can print some kind of warning when it
> > happens?
> 
> I guess the consensus is that we should put in some effort to make the
> interface more polished.
> 
Exactly! :-)

> How about this:
> 
> First, add a ratelimit_us element to csched_priv, just like the current
> tslice_ms element.
> 
> When the scheduler comes up (in csched_init), it checks to see if
> MICROSECS(sched_ratelimit_us) > MILLISECS(sched_credit_tslice_ms); if
> so, it prints a warning, and sets prv->ratelimit_us to
> 1000*prv->tslice_ms.
> 
For what it counts, I'm more than fine with just printing some
"WARNING: rate-limit > time slice is nonsense", as well as doing as you
suggest... Or even with doing both! :-P 

> In the future, when we implement the domctls to change a scheduler's
> ratelimit_us, and tslice_ms, we disallow changes which would violate the
> "ratelimit < tslice" rule (returning -EINVAL or something like that).
>
That makes a lot of sense.

Regards,
Dario

-- 
<<This happens because I choose it to happen!>> (Raistlin Majere)
-------------------------------------------------------------------
Dario Faggioli, http://retis.sssup.it/people/faggioli
Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK)
PhD Candidate, ReTiS Lab, Scuola Superiore Sant'Anna, Pisa (Italy)



[-- Attachment #1.2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 198 bytes --]

[-- Attachment #2: Type: text/plain, Size: 138 bytes --]

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel