tstile syndrome

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

Hi,
here's what I found so far on a server that show the tstile hang,
with some ddb+gdb playing.

Most processes are waiting on a tunrstile (you did know that),
the one I started with had more than 4000 writers in the queue.
The threads did come here though a VOP_LOCK() (you did also know that).
This is a tunrstile for a rwlock, I found the owner of this rwlock.
This thread is also waiting on a turnstile, but a different one,
it also did come here though a VOP_LOCK. This is also a turnstile for a
rwlock, which also has a owner, which also has VOP_LOCK in his stack
trace and is waiting on a turnstile. It's also a rwlock (I checked the
l_syncobj) but l_wchan is bogus: ffff800079ac402f, this is not a
valid krwlock_t* (and examining memory at this address doesn't look like
a valid krwlock_t value, and 'show lock' doens't know about it either). 

any idea where to go from here ?

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--