(sorry, resending but not with gmail)
Hello,
On 18/02/2026 20:31, 'Mark Brown' via KUnit Development wrote:
> On Wed, Feb 18, 2026 at 04:53:16PM +0800, David Gow wrote:
>> Le 17/02/2026 à 10:10 PM, 'Mark Brown' via KUnit Development a écrit :
>>> When running KUnit via qemu on current mailine I'm seeing random
>>> lockups, frequently but not always reporting an RCU stall.
>>> Unfortunately these don't seem to happen in a consistent place which
>>> makes it hard to figure out exactly what's going on, they started in
>>> -next at some point shortly before or early in the merge window but I've
>>> never managed to drill down and investigate them. I don't imagine
>>> they're due to KUnit specifically, though it seems likely some test is
>>> triggering them. Has anyone else seen this, or do you have any leads?
>
>> I've not been able to reproduce it after reverting the kthread affinity
>> series (git revert -m1 d16738a4e79e55b2c3c9ff4fb7b74a4a24723515), but that
>> could just be due to luck. It's flaky enough that my attempt at bisection
>> kept pointing at documentation patches.
>
> One other data point is that there's some range of commits which
> generates an actual failure in the runtime PM tests:
>
> [19:26:28] [PASSED] pm_runtime_disabled_test
> [19:26:28] Unable to handle kernel execute from non-executable memory at
> virtual address fff000000145f358
> ...
> [19:26:28] Call trace:
> [19:26:28] 0xfff000000145f358 (P)
> [19:26:28] rpm_callback+0x74/0x80
> [19:26:28] rpm_resume+0x3cc/0x6a0
> [19:26:28] __pm_runtime_resume+0x50/0x9c
> [19:26:28] device_release_driver_internal+0xd0/0x224
> [19:26:28] device_release_driver+0x18/0x24
> [19:26:28] bus_remove_device+0xd0/0x114
> [19:26:28] device_del+0x14c/0x408
> [19:26:28] device_unregister+0x18/0x38
> [19:26:28] device_unregister_wrapper+0x10/0x20
> [19:26:28] __kunit_action_free+0x14/0x20
> ...
> [19:26:28] [FAILED] pm_runtime_error_test
>
> which might upset bisections.
Yes, although I've run some automated VIXI bisections and found one
reliable panic in rcu. I had to do it in two steps as the first
bisection landed on a merge commit. After a bit more investigation I
reported what I found here:
https://lore.kernel.org/all/[email protected]/
I can bisect the other KUnit issues separately too if that helps now
that I have a quick workaround to avoid this panic (see email).
Cheers,
Guillaume
