Re: Current state of the Linux kernel on SPARC

On 8/29/25 03:45, Tony Rodriguez wrote:
> Regarding my tests:
> 
> 1)  Running non-SMP mode with 6.16.3-1 kernel makes no difference (it 
> still panics in the same fashion using nosmp keyword via grub). 
> Confirmed it was truly running in non-smp mode as well with kernel 
> 6.12.38/6.16.3-1 (which cat /proc/cpuinfo shows).
> 

I see the word "panic" and then stop. Feels like a real problem in the
Linux kernel these days for the top of the line SPARC hardware.

> 2) Believe the ISO installer is using kernel 6.12.38 during the initial 
> bootup (which at least boots).
> 
> Note: After ISO installation, if toggled via grub to use 6.12.38 the 
> s7-2 boots practically every time, but there are still plenty of tainted 
> kernel messages during boot-up.
>

Which may or may not be patched. Furthermore those patches are not in
the mainline Linux kernel ... or are they ?

If not then why not and still have no idea if they work.

> 3) Sometimes 6.16.3-1 will boot successful ...

I hear you loud and clear on that.


> Typically, only does so when previously booted using a 6.12.38 kernel 
> then rebooted using 6.16.3-1.  For kernel 6.16.3-1, often have to select 
> rescue mode or use systemd.unit=multi-user.target via grub as well.

Right. You have a whole layer of unwanted complexity layered on top of
this kernel problem. Get away from SystemD entirely. Just use a trivial
OpenRC or sysvinit type of system. You really need Gentoo here. For any
trivial testing of a kernel issue it is a disaster to use SystemD.

> *4) Also, not ruling out a possible systemd issue, noticed systemd-udevd 
> is launched shortly before 6.16.3-1 panic(s). Seems latest Debian 12 for 
> sparc64 is using systemd-258-rc3-1.  There certainly may be systemd 
> related bugs as well.
>

Remove SystemD from the equation entirely.

> 
> 5) Regarding the question:  "Thought the current Solaris 11.4 CBE 
> doesn't work on the S7, does it?
> 
>   I reset the S7-2  LDOM/Service Processor back to factory defaults 
> using ILOM CLI/web and an older Solaris 11.4 (11.4.42.113.1), without 
> using the latest Oracle Solaris CBE (11.4.81) version (since it doesn't 
> work on the S7-2). Hopefully, Oracle will resolve this S7-2 Solaris CBE 
> problem soon in a future update.
>

Do not hold your breath for anything to ever be released by Oracle that
will work on this hardware.  There is no business process to justify the
expense.

> 8) Regarding "please test Michael's patch series on your Linux 
> distribution of choice, be it Gentoo or T2DE and report back!".
> 
> Understood, want to rule out systemd first and then will try to allocate 
> additional time to research this.
> 

Remove that SystemD from the problem. Here we need to create a custom
Gentoo bootable ( or similar ) trivial ISO with the bare minimum of
kernel adjustments and modules. Anything else will just be noise on
top of a very limited signal.