Testing needed - HAMMER PFS exports via NFS

[YONETANI Tomokazu]

On Fri, Sep 26, 2008 at 11:02:01PM +0800, Sepherosa Ziehau wrote:
> On Wed, Sep 24, 2008 at 9:05 PM, YONETANI Tomokazu <qhwt+dfly at les.ath.cx> wrote:
> > On Tue, Sep 23, 2008 at 12:31:52AM +0200, Thomas Nikolajsen wrote:
> >>  - on SMP nfs server (from 21:19 also server) - didn´t notice any ill effect
> >> Sep 22 18:24:04 boy kernel: spin_lock: 0xc6087fdc, indefinite wait!
> >> Sep 22 19:08:10 boy kernel: spin_lock: 0xc6087fdc, indefinite wait!
> >> Sep 22 21:37:18 boy kernel: spin_lock: 0xc6087fdc, indefinite wait!
> >> Sep 22 22:03:27 boy kernel: spin_lock: 0xc6087fdc, indefinite wait!
> >
> > Does it cease you set kern.intr_mpsafe to 0?  I started seeing it,
> > especially frequently on DragonFly as a VMWare guest, after it's been
> > changed to 1 by default.
> 
> Could you test following patch on HEAD?
> http://leaf.dragonflybsd.org/~sephe/nata_nompsafe.diff
> 
> It works for me at least :)

Hey, you've already committed it :)  Yes, it works for me, too.
I also tweaked nata driver(using sys_cputimer->count()) and found that

- `indefinite wait!' message is displayed when spin_lock_wr() is called
  from ata_start(), to lock state_mtx
- ata_interrupt takes too long while it's holding state_mtx when it calls
  ch->hw.end_transaction. digging further, it's callout_stop() right
  below the `end_finished' label in ata_end_transaction() that is taking
  long time (> sys_cputimer->freq)

I'll try diving into callout_stop() later.

Cheers.