Create servers on different core.

[Chen Tian]

Hi Norman,

Thanks for the patch and explanation, I will work on it.

Best,
Chen

-----Original Message-----
From: Norman Feske [mailto:norman.feske at ...1...] 
Sent: Monday, June 27, 2011 2:05 AM
To: genode-main at lists.sourceforge.net
Subject: Re: Create servers on different core.

Hi Chen,

> I think we currently can only migrate those new created threads.
> However, to migrate the first thread of an application (I think it is 
> called thread0 in Genode) I need to get its capability. Do you know 
> how I can get thread0's capability with in the main function of my 
> app?

I don't think that this approach is the right way to follow. Instead, the
policy should be imposed from outside the server by the server's parent
process similar to how CPU priorities are handled. When the parent creates
the CPU session for the child, it should pass the CPU policy as session
argument to core. This makes it easy to start multiple instances of the same
program with a different policy each.

Attached to this email, you find a patch that you may use as starting point.
Please note that this is just a hacky quick shot. It enables you to specify
the CPU number at the start node of a process in init's config. In the
patch, I have modified the 'start' node of the 'demo.run'
script where you can see how to use new the "cpu" argument. The CPU number
is passed to core and ends up in the Fiasco.OC-specific constructor of
'Platform_thread'. I've put some 'PDBG' messages at the interesting points.

Please note that the CPU argument is not passed to the kernel yet - the
patch solely shows how to pass the CPU number as CPU session argument for
immediate children of init into core. As it stands, the CPU policy is not
applied to further CPU sessions created by the respective child's subsystem.
Also, the patch is known to break all base platforms except for 'base-foc'.
Anyway, I hope it can serve you as starting point for further
experimentation.

Cheers
Norman

--
Dr.-Ing. Norman Feske
Genode Labs

http://www.genode-labs.com · http://genode.org

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