On Wed, 6 Mar 2002 [EMAIL PROTECTED] wrote:

> I inserted a pair of printf() inside mtx_lock_spin/mtx_unlock_spin in
> i8254_get_timecount() and it kept printing the message while tc_init()
> was blocked, so I think it's blocked at mtx_lock_spin in i8254_get_timecount()
> when called from tc_init(), but not when called from somewhere else.
> (maybe an interrupt handler?)

Apparently you have KTR enabled (not the default in GENERIC).  I think
WITNESS+KTR already caused nasty recursion from the mtx_lock_spin, and
we now get an endless loop when nanotime() is called with an invalid
timecounter in the following call chain:

    tc_init -> tc_windup -> tco_delta -> i8254_get_timecount -> mtx_foo ->
    witness_foo -> ktr_foo -> nanotime,

just after nanotime has somehow recursed back into i8254_get_timecounter
without causing endless recursion!

Try setting MTX_NOWITNESS in the initialization of clock_lock in
i386/machdep.c.

Bruce


To Unsubscribe: send mail to [EMAIL PROTECTED]
with "unsubscribe freebsd-current" in the body of the message

Reply via email to