Re: Atomicity & preemptive kernels

[Justin Carlson <justin@cs.cmu.edu>]

On Tue, 2002-06-11 at 11:44, Jun Sun wrote:

> I see your point now.
> 
> However, the race is not there.  switch_mm() is only called from inside 
> schedule() function, which as a whole is preemption-safe.  In other words, 
> the 
> above event sequence won't cause a context switch until we exit from 
> schedule() function.
> 

Yes, but the initial code I cited was explicitly not in the schedule
function.  It was an icache_flush_page() implementation.

Just something to be careful of.  I think it's going to bite more than a
few people as a bug that's about impossible to track down...

-Justin