[LITMUS^RT] Clustered scheduling in litmus under qemu

[Youcef Amine Benabbas]

Hi Glenn,

It seems to work, thank you very much.

By the way, when I pass the following option:

"-smp 8,sockets=2,cores=2,threads=2" 

to qemu, I get a total of 8 cpus grouped into clusters of 2 cups each,
sharing a unified L2 cache. 

I think the current version of qemu only supports L2 caches.

Thanks,
Youcef

On Wed, 2012-07-04 at 13:17 -0700, Glenn Elliott wrote:
> Hi Youcef,
> 
> How is C-EDF configured for clustering?  You can configure clustering around different cache levels by writing the appropriate value to /proc/litmus/<something>/C-EDF/clustering.  However, I don't recall being able to set up shared caches, so this would mean that C-EDF (as is) can only work as P-EDF or G-EDF under qemu.  I think you might have to change C-EDF to force the clustering you want.
> 
> -Glenn
> 
> 
> On Jul 4, 2012, at 12:01 PM, Youcef Amine Benabbas wrote:
> 
> > Hi all,
> > 
> > I am trying to run litmus under qemu, simulating a system with 4 sockets
> > and 6 cores per socket.
> > 
> > Unfortunately, when I switch to the C-EDF scheduler, it  groups all cpus
> > under oner cluster; One would expect cpus to be grouped at least into
> > clusters of 4 cpus each, in order to make use of the  L3 cache.
> > 
> > Did anyone try to do this before? should I run litmus on a real machine
> > to get clustering correctly?
> > 
> > Best regards,
> > Youcef 
> > 
> > 
> > _______________________________________________
> > litmus-dev mailing list
> > litmus-dev at lists.litmus-rt.org
> > https://lists.litmus-rt.org/listinfo/litmus-dev
> 
> 
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