svn commit: r332860 - head/sys/kern

[Andrew Gallatin]

On 04/24/18 13:24, Jonathan T. Looney wrote:
> On Mon, Apr 23, 2018 at 6:04 PM, John Baldwin <jhb at freebsd.org 
> <mailto:jhb at freebsd.org>> wrote:
>  >
>  > I think this is actually a key question.  In my experience to date I 
> have not
>  > encountered a large number of post-panic assertion failures.  Given that
>  > we already break all locks and disable assertions for locks I'd be 
> curious
>  > which assertions are actually failing.  My inclination given my 
> experiences
>  > to date would be to explicitly ignore those as we do for locking if it is
>  > constrained set rather than blacklisting all of them.  However, I 
> would be
>  > most interested in seeing some examples of assertions that are failing.
> 
> The latest example (the one that prompted me to finally commit this) is 
> in lockmgr_sunlock_try(): 'panic: Assertion (*xp & 
> ~LK_EXCLUSIVE_SPINNERS) == LK_SHARERS_LOCK(1) failed at 
> /usr/src/sys/kern/kern_lock.c:541'
> 
> I don't see any obvious recent changes that would have caused this, so 
> this is probably a case where a change to another file suddenly made us 
> trip over this assert.

FWIW, that assertion has prevented me from getting a dump from an
INVARIANTS kernel for at least a year.

Drew