Re: 2.6.7-mm6

William Lee Irwin III
2004-07-07T13:05:44Z

On Wednesday 07 July 2004 01:37 am, William Lee Irwin III wrote:
>> This suspicion is correct. It boots normally with the patch you posted
>> to do that registration outside the interrupts-off critical section
>> applied. Bootlog below.

On Wed, Jul 07, 2004 at 07:47:16AM -0500, Dmitry Torokhov wrote:
> Great! I am still somewhat confused why it started locking up with sysfs
> patch - even before sunzilog was calling serio_register_port with interrupts
> off and serio core was downing it's serio_sem as the very first thing. Since
> at the time sunzilog registers its ports no serio drivers have been registered
> yet, effectively the only change introduced by sysfs patch is the call to
> device_register which takes bus' subsystem rwsem and there really should not
> be any congestion.
> Maybe rwsems can not be touched with interrupts off? Sparc only? Everywhere?
> (I know that you should not normally call functions that may sleep with
> interrupts off).

CONFIG_PREEMPT enables this to be warned on appropriately. It should
basically never happen unless it's a down_trylock() etc.

-- wli