Re: [REGRESSION] CPUIDLE_FLAG_RCU_IDLE, blk_mq_freeze_queue_wait() and slow-stuck reboots

[Linux regression tracking #update (Thorsten Leemhuis)]

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On 20.03.23 17:04, Mark Rutland wrote:
> On Mon, Mar 20, 2023 at 01:52:47PM +0000, Mark Rutland wrote:
>> On Tue, Mar 14, 2023 at 11:00:04PM +0000, Alexey Klimov wrote:
>>> #regzbot introduced: 0c5ffc3d7b15
>>> #regzbot title: CPUIDLE_FLAG_RCU_IDLE, blk_mq_freeze_queue_wait() and slow-stuck reboots
>>>
>>> The upstream changes are being merged into android-mainline repo and at some
>>> point we started to observe kernel panics on reboot or long reboot times.
>>
>> Where can I find the android-mainline repo, and which specific branch/commit
>> from that repo is being merged in?
> 
> I assume that was the android-mainline branch in:
> 
>   https://android.googlesource.com/kernel/common/
> 
> ... and I had a go with commit:
> 
>   8338670fd5bdf8d7 ("Merge "Merge 36289a03bcd3 ("Merge tag 'v6.3-p1' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6") into android-mainline" into android-mainline")
> 
> ... as that was the commit immediately before your local revert:
> 
>   a32cec8e3f2253bc ("ANDROID: Revert "cpuidle, dt: Push RCU-idle into driver")
> 
> Testing on Juno R2 with defconfig + PROVE_LOCKING=y + DEBUG_LOCKDEP=y, I cannot
> reproduce the reboot issue; everything seems to work just fine.
> 
> Can you say which config you're using?
> 
> Just to check: are you using a pristine version of that tree, or do you have
> any vendor hooks present? I note that there are special hooks added to the
> cpuidle and PSCI code, and I can imagine those might expect the old behaviour
> w.r.t. RCU and idle, so ruling those out would help.

No reply to this since more than 10 days afaics, hence for now assuming
that this is not really a regression.

#regzbot inconclusive: another dev could not reproduce issue; reporter
MIA and might have used a patched tree
#regzbot ignore-activity

Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
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