Re: CPU Lockups in KVM with deferred hrtimer rearming

Verma, Vishal L
2026-04-20T20:58:02Z

On Mon, 2026-04-20 at 17:00 +0200, Thomas Gleixner wrote:
>
> This code should never be reached with a rearm pending. Something else
> went wrong earlier. So while the patch "works" it papers over the
> underlying problem.
>
> Can you please do the following:
>
>     1) Apply the patch below
>
>     2) Enable function tracing and the hrtimer* trace events
>
>     3) Enable tracing if it has been disabled already
>
>        echo 1 >/sys/kernel/tracing/tracing_on
>
>     4) Run the tests and wait for /sys/kernel/tracing/tracing_on to
>        become 0, which means the problem triggered.
>
>     5) Retrieve the trace from /sys/kernel/tracing/trace and provide it
>        somewhere to download from or send it to me compressed offlist.

Hi Thomas,

I've uploaded the trace here (~75MB compressed):
https://drive.proton.me/urls/B9PY61XQ0C#07XwTVhE46eB

As for:

1f5ffc672165 ("Fix mismerge of the arm64 / timer-core interrupt handling changes")

I already had that commit in the branch that was tested and it didn't
fix it.