RE: [Xen-devel] performance problems...

["James Harper" <james.harper@xxxxxxxxxxxxxxxx>]

Ha! Look at that. I did:

xm sched-sedf Domain-0 0 0 0 1 1
xm sched-sedf mail 0 0 0 1 1

and now I can do a cpuburn (burnP6) in dom0 and you barely notice it.

So... questions...

Sedf must be the default scheduler? I always thought it was bvt? What
are the default settings for it? Obviously they aren't optimal in my
case!

How can I query the current scheduler settings?

Thanks

James

> -----Original Message-----
> From: Mark Nijmeijer [mailto:mark@xxxxxxxxxxxxx]
> Sent: Friday, 13 January 2006 12:17
> To: James Harper
> Subject: Re: [Xen-devel] performance problems...
> 
>  From the xen-users mailing list, can you try this ?
> 
> 2) Scheduling issue
> 
> The system was unusable with high CPU load in dom0, all other domains
> were almost dead, and there's apparantly no comprehensive
documentation
> of xen's schedulers (please point out the relevant docs to me if I'm
> wrong, all I found was sedf_scheduler_mini-HOWTO.txt,
> xenwiki/Scheduling and `man xm`, none of which helps to understand
> scheduling well enough to change its parameters). Thanks to Tim
Freeman
> I found an easy setup that works for me: I set the scheduling
parameters
> for all domains via "xm sched-sedf <domID> 0 0 0 1 1" or something
> similar corresponding to example "4 domains with weights 2:3:4:2" from
> the sedf_scheduler_mini-HOWTO.txt with an additional 1 as the
extratime
> parameter if you want to allow a domain to allocate more CPU time if
> other domains are idle.
> 
> 
> 
> James Harper wrote:
> 
> >>>Any suggestions as to where to start? Or is this a known and
> >>>solved problem in the latest -testing?
> >>>
> >>>
> >>There have been no changes in 3.0-testing that are likely relevant.
I
> >>don't think anyone else has reported this, so I'd look closely at
your
> >>bridging changes. Also please report the test setup in more detail.
> >>
> >>
> >You
> >
> >
> >>haven't connected dom0 directly to the bridge rather than vif0.0 to
> >>
> >>
> >the
> >
> >
> >>bridge have you?
> >>
> >>
> >>
> >
> >I just upgraded both my xen machines to the latest (yesterdays hg
pull)
> >and both appear to be doing the same thing now. One of them is SMP
> >though, so the problem is less apparent, but if do a 'cpuburnP6' on
> >dom0, the domU's slow down to a crawl.
> >
> >The problem really does appear to be scheduling related, not network,
so
> >I haven't adjusted the network bridge configuration yet, but will do
so
> >if you tell me it's worth a go.
> >
> >Thanks
> >
> >James
> >
> >_______________________________________________
> >Xen-devel mailing list
> >Xen-devel@xxxxxxxxxxxxxxxxxxx
> >http://lists.xensource.com/xen-devel
> >
> >


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