Re: new panic in cpu_reset() with WITNESS

on 24/01/2012 13:54 Gleb Smirnoff said the following:
> On Mon, Jan 23, 2012 at 06:56:08PM +0200, Andriy Gapon wrote:
> A> on 23/01/2012 18:46 Gleb Smirnoff said the following:
> A> > On Mon, Jan 23, 2012 at 06:43:23PM +0200, Andriy Gapon wrote:
> A> > A> > db> bt
> A> > A> > Tracing pid 1 tid 100001 td 0xfffffe0001d5e000
> A> > A> > kdb_enter() at kdb_enter+0x3b
> A> > A> > panic() at panic+0x1c7
> A> > A> > _mtx_lock_spin_flags() at _mtx_lock_spin_flags+0x10f
> A> > A> > cnputs() at cnputs+0x7a
> A> > A> > vprintf() at vprintf+0xcb
> A> > A> > printf() at printf+0x67
> A> > A> > db_putc() at db_putc+0x81
> A> > A> 
> A> > A> Ah, db_putc does something different from what I expected.
> A> > A> Can you hack it to never use printf?
> A> > 
> A> > Just cut printfs from db_putc()?
> A> 
> A> Make the following condition be always false:
> A> 
> A> if (!kdb_active || ddb_use_printf) {
> A> 
> A> E.g.:
> A> 
> A> if (0) {
> 
> With this change + s/printf/db_printf/ in subr_witness.c I've
> got the following during reboot:
> 
> Rebooting...
> lllock order reversal:
>  1st 0xffffffff80937140 smp rendezvous (smp rendezvous) _at_ /usr/src/head/sys/kern/kern_shutdown.c:542
>  2nd 0xffffffff80b13280 syscons video lock (syscons video lock) _at_ /usr/src/head/sys/dev/syscons/syscons.c:1921
> panic: mtx_lock_spin: recursed on non-recursive mutex cnputs_mtx _at_ /usr/src/head/sys/kern/kern_cons.c:500

Can you disable video console?

-- 
Andriy Gapon