Patching Dovetail with xenomai-3

Patching Dovetail with xenomai-3

[Auel, Kendall]

For months I have been using the xenomai-3 v3.2.2 tag when patching
the linux-dovetail kernel source from there. Today I turned on the debug
options in the kernel (specifically looking for relaxes) and got the
VM_DENYWRITE error reported about a year ago. Comparing the
v3.2.2 tag with master I see that the ipipe code has been removed
along with other structural changes.

So my question is: what version of xenomai-3 is best for patching the
5.15.77 Dovetail kernel (for example)? I don't see any tags or branch
versions that are obvious for Cobalt on Dovetail. Should I simply go
with master?

Thanks!
Kendall Auel
3D Systems, Inc.

Re: Patching Dovetail with xenomai-3

[Jan Kiszka]

On 14.12.22 19:59, Auel, Kendall wrote:
> For months I have been using the xenomai-3 v3.2.2 tag when patching
> the linux-dovetail kernel source from there. Today I turned on the debug
> options in the kernel (specifically looking for relaxes) and got the
> VM_DENYWRITE error reported about a year ago. Comparing the
> v3.2.2 tag with master I see that the ipipe code has been removed
> along with other structural changes.
> 
> So my question is: what version of xenomai-3 is best for patching the
> 5.15.77 Dovetail kernel (for example)? I don't see any tags or branch
> versions that are obvious for Cobalt on Dovetail. Should I simply go
> with master?

Stable 3.2.x supports up to kernel 5.10 officially (that's what we
test), but it may work with 5.15 as well because many adjustments needed
for it hit 3.2 as well. Would take someone to look into that, possibly
suggesting more patches from master.

So the safer bet with 5.15 is master for now.

Jan

-- 
Siemens AG, Technology
Competence Center Embedded Linux

RE: Patching Dovetail with xenomai-3

[Auel, Kendall]

> From: Jan Kiszka <jan.kiszka@siemens.com>
> Sent: Wednesday, December 14, 2022 11:39 AM
> To: Auel, Kendall <Kendall.Auel@3DSystems.Com>; xenomai@lists.linux.dev
> Subject: Re: Patching Dovetail with xenomai-3
> 
> On 14.12.22 19:59, Auel, Kendall wrote:
> > [...]
> > So my question is: what version of xenomai-3 is best for patching the
> > 5.15.77 Dovetail kernel (for example)? I don't see any tags or branch
> > versions that are obvious for Cobalt on Dovetail. Should I simply go
> > with master?
> 
> Stable 3.2.x supports up to kernel 5.10 officially (that's what we test), but it
> may work with 5.15 as well because many adjustments needed for it hit 3.2
> as well. Would take someone to look into that, possibly suggesting more
> patches from master.
> 
> So the safer bet with 5.15 is master for now.
> 
> Jan

Thanks Jan.

I can now see the file /proc/xenomai/debug/relax but try as I might I can't
seem to get any spurious relaxes to occur (or, at least, get logged).

Even if I run switchtest, nothing is logged. Is this expected, or maybe a
limitation of Cobalt on Dovetail? I'm suspicious that my RT thread is getting
spurious relaxes due to some occasional unexpected behavior but I'm
not sure if I can debug it with 5.15.77 (or 5.10.157 for that matter).

I'm hoping this is a case of pilot error, some simple configuration issue.
Any advice?

Thanks,
Kendall