Re: BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low!

[Mikhail Gavrilov]

On Tue, Jul 26, 2022 at 9:47 PM David Sterba <dsterba@xxxxxxx> wrote:
>
> On Tue, Jul 26, 2022 at 05:32:54PM +0500, Mikhail Gavrilov wrote:
> > Hi guys.
> > Always with intensive writing on a btrfs volume, the message "BUG:
> > MAX_LOCKDEP_CHAIN_HLOCKS too low!" appears in the kernel logs.
>
> Increase the config value of LOCKDEP_CHAINS_BITS, default is 16, 18
> tends to work.

Hi,
Today I was able to get the message "BUG: MAX_LOCKDEP_CHAIN_HLOCKS too
low!" again even with LOCKDEP_CHAINS_BITS=18 and kernel 6.2-rc5.

❯ cat /boot/config-`uname -r` | grep LOCKDEP_CHAINS_BITS
CONFIG_LOCKDEP_CHAINS_BITS=18

[88685.088099] BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low!
[88685.088124] turning off the locking correctness validator.
[88685.088133] Please attach the output of /proc/lock_stat to the bug report
[88685.088142] CPU: 14 PID: 1749746 Comm: mv Tainted: G        W    L
  -------  ---  6.2.0-0.rc5.20230123git2475bf0250de.38.fc38.x86_64 #1
[88685.088154] Hardware name: System manufacturer System Product
Name/ROG STRIX X570-I GAMING, BIOS 4408 10/28/2022

What's next? Increase this value to 19?
Actual full kernel log and lock_stat attached below.

-- 
Best Regards,
Mike Gavrilov.

Attachment: dmesg.tar.xz
Description: application/xz

Attachment: lock_stat.tar.xz
Description: application/xz