5.4-p1 crash

[Robert Watson]

On Sat, 18 Jun 2005, Philippe PEGON wrote:

>> Unfortunately this is a known bug in FreeBSD; check the archives for
>> more discussion.  Doug White tried to look at fixing it before
>> 5.4-RELEASE but I think he gave up.
>
> do you know if someone works on it ? I sent two mail in freebsd-stable 
> about it without solution and this bug is really annoying :
>
> http://lists.freebsd.org/mailman/htdig/freebsd-stable/2005-June/015952.html
>
> and
>
> http://lists.freebsd.org/mailman/htdig/freebsd-stable/2005-June/015864.html
>
> there is a PR for it : kern/74319

This sounds very similar to a serial console related tty bug I was 
experiencing on -STABLE a few months ago, and that is believed may have 
been worked around in 5.4 tweaks before release.  In particular, that 
there are reference counting related bugs in the 5.x tty code that are 
fixed by a partial rewrite of the tty code in 6.x, but that are too large 
and disruptive to merge to RELENG_5.  If the problem is persisting, it may 
be worth trying to merge anyway, but it is a pretty big change and would 
break device driver binary compatibility, etc.  What we might want to do 
here is wait until 6.x has settled out a bit more, then consider merging 
it to 5.x once 6.x has gotten burned in with similar workloads and 
continued to not illustrate the 5.x tty reference bugs.

Robert N M Watson