Hi Oliver,
On 22/03/2021 08:29, Oliver Schwartz wrote:
Andrea,
I’m currently evaluating the benefits of cache coloring in jailhouse.
In my application I have a setup with two cells, the root cell for
communication purposes and an inmate cell for a realtime application. The
system is running on a Xilinx ZynqMP. With the arm64-zero-exits patches the
realtime cell runs without hypervisor exits after startup.
If io load in the root cell increases (e.g. with network traffic) I can see
some impact on the performance of the realtime cell. Possible reasons might be
bus congestion or cache conflicts. Since I’d like to minimize the effect, cache
coloring is an obvious choice.
The current set of patches for cache coloring doesn’t help a lot in my case,
since only the inmate cell can be colored. In fact, the performance is worse
than without cache coloring (presumably because less cache is available for the
inmate).
My question is this: Is there some prototype code available for root cell cache
coloring? You mentioned on the list that you had done some experiments with
this. I’m aware of the limitations that this may have and the concerns that Jan
has voiced for this approach - however, at the present stage I’d be happy even
with some hacky approach (be it in Linux, U-Boot or Jailhouse) to investigate
whether cache coloring provides a benefit to my setup.
Yes, with BU and UniMore we have been experimenting (mainly on the ZCU102) with
coloring the root cell during the enable phase of jailhouse (what we call
"dynamic recoloring").
I'd say your timing is "perfect" :-) I took the chance to rebase our version of
the dynamic recoloring on top of the just sent PATCH v2.2.
You can find the full stack of the patches here:
https://gitlab.com/bastoni/jailhouse/-/tree/for_upstream/202103_coloring_dyn-recolor
Let us know if it helps in your scenario!
--
Andrea Bastoni, Ph.D.
Research Fellow
Technische Universität München
Lehrstuhl für Cyber-Physical Systems in Production Engineering
--
You received this message because you are subscribed to the Google Groups
"Jailhouse" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/jailhouse-dev/d108cd39-248c-2938-e5fc-7e7afd1b995c%40tum.de.
