Hi!
> > Ok, so linux actually atomicity of long?
^~-- assumes should be here.
> No it doesn't. And even if it did you couldn't use long for this because
> atomic_t also ensures the points operations complete are defined. You
> might just about get away with volatile long * objects on x86 for simple
> assignments but for anything else gcc can and will generate code to
> update values whichever way it feels best - which includes turning
>
> long *x = a + b;
>
> into
>
> *x = a;
> *x += b;
Ok, I can understand the gcc side. But do we actually run on an
architecture where
long *x;
*x = 0;
racing with
*x = 0x12345678;
can produce
*x == 0x12340000;
or something like that? I'm told RCU relies on architectures not doing
this, and I'd like to get this clarified.
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
_______________________________________________
linux-pm mailing list
linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linux-foundation.org/mailman/listinfo/linux-pm
