Re: panic: Duplicate free of item 0xffffff005c4a8600 fromzone0xffffff007fed4780(Mbuf)

From: "Robert Watson" <rwatson_at_freebsd.org>
> On Mon, 19 Jul 2004, Willem Jan Withagen wrote:
>
> > > I'll starts some more tests before I'm of to bed.
> >
> > This mornings result:
> > ====
> > System call getdirentries returning with the following locks held:
> > exclusive sleep mutex bdone lock r = 0 (0xffffffff805fd080) locked _at_
/home2/src/
> > sys/kern/vfs_bio.c:3767
> > panic: witness_warn
> > cpuid = 0;
> > KDB: stack backtrace:
> > kdspin lock sched lock held by 0xffffff007b6cc940 for > 5 seconds
> > panic: spin lock held too long
> > cpuid = 0;
> > KDB: enter: panic
> > ====
> >
> > But no way to get into the debugger.  Does not look like it is much
> > network related???
>
> Doesn't look very network related, although it could be that increased
> concurrency and lack of waiting on Giant open up a race of some sort.  Can
> you confirm "options DDB" and "options KDB" are both in your kernel
> config?  You may want to consider commenting out "#define PREEMPTION" in
> the copy of params.h for the architecture you're running on and see if
> that helps.  Won't help interrupt processing latency, but probably won't
> hurt server throughput, and your box is a server box so it might be worth
> trying.

The first time that it made it through the night since quite some days...
The real stress test, "make -j32 buildworld" is still too much however.

--WjW