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


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