[ZFS] panic vm_fault : fault on no fault entry (when superpages are enabled)

[Patrick Lamaiziere]

Le Thu, 17 Sep 2009 13:21:27 +0200,
Patrick Lamaiziere <patfbsd at davenulle.org> a écrit :

Hello,

> [8.0 BETA-4/i386]
> 
> I've got this panic when copying /usr on a new pool.
> It's 100% reproductible here with 
> tar cf - -C /usr . | tar xpvf - -C /pool
> 
> The panic occurs always with free() in the ZFS code.

...

> /boot/loader.conf
> # ZFS
> vm.kmem_size="512M"
> vm.kmem_size_max="512M"
> vfs.zfs.arc_max="40M"
> vfs.zfs.vdev.cache.size="5M"
> 
> and options KVA_PAGES=512 in my kernel

I think I've found the culprit: superpages.

With vm.pmap.pg_ps_enabled="1", my box will panic in the next
five minutes when doing a simple tar on ZFS.

Looks good without the superpages. Is it a known problem?

Thanks, regards.