ZFS kmem_map too small.

Hi.

We'are about to branch RELENG_7 and I'd like to start discussion with
folks that experience 'kmem_map too small' panic with the latest HEAD.

I'm trying hard to reproduce it and I can't, so I need to gather more
info how you are able to provoke this panic.

What I did was to rsync 200 FreeBSD src trees from one directory to
another on the same ZFS file system. It worked fine.

The system I'm using is i386 and the only tuning I did is bigger
kmem_map. From my /boot/loader.conf:

vm.kmem_size=629145600
vm.kmem_size_max=629145600

The machine is dual core Pentium D 3GHz with 1GB of RAM. My pool is:

lcf:root:/tank/0# zpool status
  pool: tank
 state: ONLINE
 scrub: none requested
config:

        NAME        STATE     READ WRITE CKSUM
        tank        ONLINE       0     0     0
          ad4       ONLINE       0     0     0
          ad5       ONLINE       0     0     0
          ad6       ONLINE       0     0     0
          ad7       ONLINE       0     0     0

errors: No known data errors

If you can still see those panic, please let me know as soon as possible
and try to describe what your workload looks like, how to reproduce it,
etc. I'd really like ZFS to be rock-stable for 7.0 even on i386.

-- 
Pawel Jakub Dawidek                       http://www.wheel.pl
pjd_at_FreeBSD.org                           http://www.FreeBSD.org
FreeBSD committer                         Am I Evil? Yes, I Am!