Re: [PATCH] 2nd try: i386 rw_semaphores fix

From: Andreas Franck (afranck@gmx.de)
Date: Wed Apr 11 2001 - 10:00:45 EST


Hello David,

> I've been discussing it with some other kernel and GCC people, and they
> think
> that only "memory" is required.

Hmm.. I just looked at my GCC problem report from December, perhaps you're
interested, too:

http://gcc.gnu.org/ml/gcc-bugs/2000-12/msg00554.html

The example in there compiles out-of-the box and is much easier to
experiment on than the whole kernel :-)

It should reflect the situation in the kernel as of December 2000, where no
outputs were declared at all.

I can try this examples again with current GCC snapshots and will see if I
can find a working solution without reserving more registers.

> Apart from the risk of breaking it, you mean? Well, "=m" seems to reserve
> an
> extra register to hold a second copy of the semaphore address, probably
> since
> it thinks EAX might get clobbered.
>
> Also, as a minor point, it probably ought to be "+m" not "=m".

Perhaps, I'm no real expert on this things, and "=m" worked for me, so
I used it :)

Greetings,
Andreas

-- 
GMX - Die Kommunikationsplattform im Internet.
http://www.gmx.net

- 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/



This archive was generated by hypermail 2b29 : Sun Apr 15 2001 - 21:00:16 EST