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Re: [Xen-devel] BVT scheduler settings examples

> Are there any examples of bvt scheduler parameters usage?

Not to my knowledge. We should document such things, but this is a bit time 

> If I understand it right, bvt provides me with option to scale domain's
> CPU usage. Eg. I have 2 (non-zero) domains pinned to the same CPU. Can I
> assign eg. 30% of CPU time to domain 1 and 70% to domain 2? (I mean in
> peaks when both domains are not idle and require the CPU time)

Right. BVT supports weights.

> If yes, how should I build the "xm bvt" command? I tried to only set the
>   MCUADV value, but "xm" requires all parameters to be present. I don't
> know what values should I set to the others, so any example would help.

Ok, so here is small explanation and a few examples:
xm bvt takes the following arguments:
DOM - domain id
MCUADV - inverse of weight. Therefore if you want to give more CPU decrease 
WARPBACK - boolean, enables domain to execute before other domains after 
waking up, decreases lattency, useful for driver domains
WARPVALUE - the bigger the value the greater number of domais will be 
WARPL - if warpback is enabled, limit the time that it is enabled for 
WARPU - after warping was disabled by WARPL enable it again after WAPRU

So if you want 30/70 you can do the following:
xm bvt 1 47 0 0 0 0
xm bvt 2 20 0 0 0 0
(since 47/20 ~= 2.33  and 70/30=2.33)
the MCUADV is integer, so in order to increase the granurality you can give 
bigger values. Only the relative value matters.

You can read more about BVT here:

Any more questions. I am happy to help.


Quidquid latine dictum sit, altum viditur --- Anon

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