Re: wapbl panic on new system with too much memory!

[Paul Goyette <paul%whooppee.com@localhost>]

FWIW, this seems to be something specific to wapbl.  I was able to boot 
single-user, tunefs the file systems to set the log size to zero, and 
edit /etc/fstab (to remove -o log).  Once I did this, and wapbl was thus 
completely disabled, the system came up just fine.

I know that the amount of memory is unlikely to be the root cause of the 
problem, but I don't have a clue on where to go next.  I'd like to have 
wapbl working again...



On Tue, 6 Sep 2016, Paul Goyette wrote:

> I'm in the process of installing a new machine, and I'm getting a 
> reproducible panic at boot time.
>
> The machine is a Intel Core i7-6900 (8 cores, 16 threads, 3.2GHz) on an ASUS 
> X99-E motherboard.  It is fully-populated with 8 x 16GB DDR4 DIMMs (for a 
> total, yes, of 128GB!).
>
> Basically, I cloned the hard drive of my other machine using dd, and then put 
> the copy in the new machine, and booted.  It comes up fine in single-user 
> mode.  However, shortly after typing ^D to the single-user shell, it fails a 
> KASSERT at sys/kern/vfs_wapbl.c line 1088.  The following is manually 
> transcribed:
>
> 	trap type 1 code 0 rip ffffffff80114cf5 cs8 rflags 246 cr2
> 	7ef4986dd3d0 ilevel 0 rsp fffffe90eb210b10
>
> 	ddb> bt
>
> 	breakpoint + 0x5
> 	vpanic + 0x140
> 	cd_play_msf (ie, end of panic()!)
> 	wapbl_add_buf + 0x134
> 	bdwrite + 0xbd
> 	ffs_update.part.3 + 0x1f0
> 	ffs_full_fsync + 0x187
> 	ffs_fsync + 0x4b
> 	VOP_FSYNC + 0x3e
> 	ffs_sync + 0xd0
> 	VFS_SYNC + 0x1c
> 	do_sys_sync + 0xb3
> 	sys_sync + 0x9
> 	syscall + 0x15b
> 	--- syscall number 36 ---
>
> I have four file systems on the single hard drive, and all of them are 
> mounted '-o log' (ie, wapbl enabled).
>
> Upon reboot, I manually forced an fsck of all file systems via 'fsck -fp' and 
> no issues were found.  I then did a sync;sync;sync without any problems.  But 
> again, as soon as I ^D from the single-user shell, I got the same panic.
>
> Anyone got any clues?
>
>
> +------------------+--------------------------+------------------------+
> | Paul Goyette     | PGP Key fingerprint:     | E-mail addresses:      |
> | (Retired)        | FA29 0E3B 35AF E8AE 6651 | paul at whooppee.com   |
> | Kernel Developer | 0786 F758 55DE 53BA 7731 | pgoyette at netbsd.org |
> +------------------+--------------------------+------------------------+

+------------------+--------------------------+------------------------+
| Paul Goyette     | PGP Key fingerprint:     | E-mail addresses:      |
| (Retired)        | FA29 0E3B 35AF E8AE 6651 | paul at whooppee.com   |
| Kernel Developer | 0786 F758 55DE 53BA 7731 | pgoyette at netbsd.org |
+------------------+--------------------------+------------------------+