Hi,
So far, EmbeddedXEN - which is not XEN - dedicates one CPU per domain, i.e. dom0 is assigned the CPU0, while domU CPU1.
It's not SMP, but AMP; actually, the hypervisor is able to manage both cores, but we do not balance CPUs to multiple domains.
For the time being, there is only one timer source (physical) which is assigned to dom0. Dom0 keeps processing all physical IRQs,
i.e. only CPU0 is able to process these interrupts. CPU1 on the other hand gets some softint interrupts from CPU0 to process VIRQ (timer & others).
Regards
Dan
From: akshay st [mailto:aks...@ya...]
Sent: mercredi 10 juin 2015 19:14
To: Rossier Daniel
Cc: EmbeddedXen
Subject: Re: ARM A9 SMP Xen source code
Hi,
Thanks for the path,
I didn't go through the code still, but i have following doubts/questions at high level
If we have 2 cpu's xen will have 2 threads , so it can schedule and run 1 dom0 and domu independently?. However if we assume domu wants to sleep, then will both cpu;s be allocated to dom0?
Also if dom0 and domu r both running on different cpu's, then how will load balancing be handled in Linux , as it assumes both cpus are running simultaneously? if linux DOM0 is running on cpu0 and DOMu is running on cpu1 , then when load balancing is triggered DOM0 running on cpu0 may pull lots of tasks from DOMu running on cpu1? so this may adversly affect performance?.
Also i assume interrupts can be routed to different linux running on different cpu's? Ex;- DOM0 running on cpu0 configured 1 timer interrupt on cpu1, DOMU may be running on CPU1 at that time, so when we get interrupt on cpu1 it should go to cpu0?
Planning to go over following for A9 SMP , Is this correct
hypervisor-4.0.2<http://sourceforge.net/p/embeddedxen/code/ci/LG_work/tree/hypervisor-4.0.2>
linux-3.4.6-domU<http://sourceforge.net/p/embeddedxen/code/ci/LG_work/tree/linux-3.4.6-domU>
linux-3.4.0-nexus5-dom0<http://sourceforge.net/p/embeddedxen/code/ci/LG_work/tree/linux-3.4.0-nexus5-dom0>
Will have more questions once i start going over the sources. Do u have any documentation on changes done for Xen for A9 SMP? .
Warm Regards,
Akshay
On Wednesday, 10 June 2015 11:32 AM, Rossier Daniel <Dan...@he...<mailto:Dan...@he...>> wrote:
Hi,
The ARM A9 SMP can be retrieved from the git source. There is branch called LG_work in which you can find some contributions from LG Network which supports SMP.
We will release in the upcoming months a new release of EmbeddedXEN (now called EmbX) on github, with a lot of new features.
Stay tuned…
Dan
From: akshay st [mailto:aks...@ya...]
Sent: lundi 1 juin 2015 11:31
To: Rossier Daniel
Cc: EmbeddedXen
Subject: ARM A9 SMP Xen source code
Few years back i was working on Single core XEN , i now need ARM A9 SMP Xen Hypervisor and sample Linux code , Can someone point me to the source code path?
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