Am Mittwoch, 24. August 2005 20:22 schrieb linux-os (Dick Johnson):
> > sorry but I'm not sure to understand you...Do you mean that the first write
> > into reg_a pointer will be completed before the second write because they're
> > separated by a (;) ?
>
> Yes. The compiler must make sure that every effect of all previous
> code and all side-effects are complete at a "sequence-point". There
> are several sequence-points and the most obvious is a ";".
What the compiler may or may not generate is a little beside the point.
You have no guarantee that the CPU will execute these instructions in
the order given. If you need ordered writes use the appropriate barriers,
eg. wmb();
If this is PCI you also need to worry about the bridge caching. You
need to do dummy reads.
Regards
Oliver
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
|
|