Re: [PATCH 1/1] Xen ARINC 653 Scheduler (updated to add support for CPU pools)

[Juergen Gross <juergen.gross@ts.fujitsu.com>]

On 06/16/2010 06:20 PM, Keir Fraser wrote:
> On 16/06/2010 17:14, "George Dunlap"<George.Dunlap@eu.citrix.com>  wrote:
>
>>>   I actually tried the xmalloc() method first.  I found that when the
>>> .adjust_global function was called, the address of the "ops" data structure
>>> passed to that function was different from the address of the "ops" data
>>> structure when the .init function was called.  I wanted to use .adjust_global
>>> to modify the data structure that was created when the .init function was
>>> called, but I could not figure out a way to get the address of the second
>>> data structure.  Suggestions?
>>
>> It's been a month or two since I trawled through the cpupools code;
>> but I seem to recall that .init is called twice -- once for the
>> "default pool" (cpupool0), and once for an actually in-use pool.
>> (Juergen, can you correct me if I'm wrong?)  Is it possible that
>> that's the difference in the pointers that you're seeing?
>
> Oh yes, that was the old behaviour. I took a hatchet to the
> scheduler/cpupool interfaces a few weeks ago and now we should only
> initialise the scheduler once, unless extra cpupools are manually created.

Keir, what do you think about creating an "idle-scheduler" for the cpus not in
any cpupool? It would only schedule the idle vcpu and could be VERY minimal.
This could reduce the complexity of moving cpus from and to cpupools.

I could try to setup a patch if you support this idea (I'm asking for your
opinion before starting this, as I'm rather busy with other tasks).


Juergen

P.S.: George, you still seem to use my old mail address which isn't valid any
       more...

-- 
Juergen Gross                 Principal Developer Operating Systems
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