Re: [BUG] btrfs: MAX_LOCKDEP_CHAIN_HLOCKS too low!

[Mirsad Goran Todorovac]

Hi, Qu, David,

On 6/27/23 16:27, David Sterba wrote:
> On Tue, Jun 27, 2023 at 08:19:37AM +0800, Qu Wenruo wrote:
> > On 2023/6/27 07:40, Mirsad Goran Todorovac wrote:
> > > Hi,
> > >
> > > There is a bug apparently in btrfs file system.
> > >
> > > The platform is an assembled box with Ryzen 9 processor and ASRock X670E PG
> > > Lightning motherboard.
> > >
> > > I do not have a reproducer, just kernel log:
> > >
> > > Jun 26 20:41:58 defiant kernel: [ 2273.786736] BUG:
> > > MAX_LOCKDEP_CHAIN_HLOCKS too low!
> >
> > This is really what it said.
> >
> > The setting is too low for certain workload.
> >
> > In fact Fedora is already increasing this value.
> > If you want lockdep, I guess that's the only way to go.
>
> https://btrfs.readthedocs.io/en/latest/dev/Development-notes.html#bug-max-lockdep-chain-hlocks-too-low
>
> As the reports will probably keep coming until lockdep changes I'll move
> the answer to a more user-visible page.

Thank you for your prompt response. It wasn't obvious from the kernel
message though which .config setting needs adjustment.

I am yet unable to tell whether the lockdep setting being too low and
turning off the locking correctness validator caused the kernel crash, but
I will know more after restarting the kselftest with the new lockdep
setting ...

Best regards,
Mirsad Todorovac