Re: the stuttering regression in 7.0: should I have done something different?

[Thorsten Leemhuis]

[+tglx so he knows about it; details about the problem that Tony faces
can be found in https://github.com/sparclinux/issues/issues/79 ]

On 5/8/26 09:38, Tony Rodriguez wrote:
> I still don't believe this is fixed upstream as of v7.03 and v7.1-rc1,

Yes and no. It looks like d6e152d905bdb1 ("clockevents: Prevent timer
interrupt starvation") causes two regression.

Thomas fixed one with 4096fd0e8eaea1 ("clockevents: Add missing resets
of the next_event_forced flag") -- and feedback shows that it definitely
solved the problem for quite a few people. If that's not the case for
you, then you seem to face a different problem caused by the same
change. Happens, that's life sometimes.

Ciao, Thorsten

> only when my patch is applied does the SPARC74 S7-2 system become stable
> again. I also tested my patch with v7.04 and it works their as well.
> Will perform additional tests without my fix against v7.0.4 and v7.1-rc2
> later today to revalidate the regression (USA Pacific time).
> 
> Tony Rodriguez
> www.linkedin.com/in/unixpro1970
> 
>> On May 7, 2026, at 11:33 PM, Thorsten Leemhuis <linux@xxxxxxxxxxxxx>
>> wrote:
>>
>> On 5/8/26 07:51, John Paul Adrian Glaubitz wrote:
>>> On Thu, 2026-04-23 at 18:30 +0200, Thorsten Leemhuis wrote:
>>>> FWIW, here is the rough timeline of the regression, just to be sure we
>>>> are all on the same page:
>>>>
>>>> * The regression I'm talking about is caused by d6e152d905bdb1
>>>> ("clockevents: Prevent timer interrupt starvation") [authored:
>>>> 2026-04-07 10:54:17; committed: 2026-04-10 22:45:38; next arrival:
>>>> next-20260413; merged: 2026-04-12 19:01:55; v7.0 (2026-04-12 22:48:06)]
>>> [...]
>>> Tony Rodriguez from the SPARC community has observed the regression
>>> on SPARC as well
>>> and proposed a fix to address it [1]. Not sure whether he has
>>> retested on the latest
>>> commit of Linus' tree yet.
>>>
>>> Tony, can you verify that 4096fd0e8eaea1 fixes the issue for you?
>>>
>>>> [1] https://github.com/sparclinux/issues/issues/79
>>
>> It's likely a different regressions, as that report's title says that
>> v7.0.1, v7.0.2, v7.0.3, and v7.1‑rc1 are affected, which all contain the
>> fix, aka 4096fd0e8eaea1. Reporting in a new thread is likely best, as
>> the authors of the culprit are not even CCed here.
>>
>> Ciao, Thorsten