http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50065
--- Comment #10 from Mikael Pettersson <mikpe at it dot uu.se> 2011-08-16
07:24:48 UTC ---
(In reply to comment #9)
> > Regarding the spinlock_unlock in linux, the regular arch_spin_unlock is
> > implemented with a single inline assembly. That will prevent the memory
> > reordering in C. However, for the 32-bit port the arch_write_unlock is still
> > defined as the following without a memory barrier in
> > arch/sparc/include/asm/spinlock_32.h
> >
> > #define arch_write_unlock(rw) do { (rw)->lock = 0; } while(0)
> >
> > OTH, the 64-bit implemention is ok. Or did I miss something here.
> > Anyway, I think this is a separated issue from this thread.
>
> The discrepancy is a little surprising, indeed.
That was a bug in the sparc32 Linux kernel. I sent a patch yesterday to fix
it.
