Re: 2.4.18 Preempt Freezeups

yodaiken@fsmlabs.com
Fri, 15 Mar 2002 17:40:36 -0700


On Fri, Mar 15, 2002 at 02:11:49PM -0500, Robert Love wrote:
> If you "poke the processor", to be SMP-safe, you should hold a lock to
> prevent multiple concurrent "pokings of the processor" - thus you become
> preempt-safe.

Without preempt:
x = movefrom processor register;
do_something with x

is safe in SMP
With SMP it requires a lock.

-- 
---------------------------------------------------------
Victor Yodaiken 
Finite State Machine Labs: The RTLinux Company.
 www.fsmlabs.com  www.rtlinux.com

- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/