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

[Peter Zijlstra]

On Fri, Mar 17, 2023 at 02:11:25AM +0000, Alexey Klimov wrote:
> On Wed, 15 Mar 2023 at 11:16, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> >
> >
> > (could you wrap your email please)
> 
> Ouch. Sorry.
> 
> > 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.
> >
> > On what hardware? I find it somewhat hard to follow this DT code :/
> 
> Pixel 6.

What actual cpuidle driver is that thing using? Is there any out-of-tree
code involved? Mark tells me anything arm64 should be using PSCI, so let
me to stare hard at that again.