Re: [BUG] __write_lock_failed() oops

[William Lee Irwin III]

On Thu, Sep 05, 2002 at 01:32:40AM -0700, William Lee Irwin III wrote:
>> (gdb) p/x $eax
>> $25 = 0xc0331ca0
>> (gdb) p &tasklist_lock
>> $27 = (rwlock_t *) 0xc0331ca0

On Thu, Sep 05, 2002 at 01:45:02AM -0700, William Lee Irwin III wrote:
> The NMI oopser is going here as well (nmi_watchdog=2 for extra safety)
> so I suspect the tasklist_lock semantics are behaving badly. But it's
> not easily reproducible enough to test a quick attempt at a fix if it
> can't be recognized a priori.
> This is literally so difficult to reproduce it hasn't been seen in 2
> releases. kgdb is still going and dhowells is helping me fish stuff
> off the stack.

According to dhowells' analysis, the NMI oopser fired while do_fork()
spun on the tasklist_lock. The contention on the bloody thing is so bad
the kernel cannot survive the NMI oopser. Something is majorly FITH here.
GRRRR!!!

Cheers,
Bill