[kGDB]Cannot compile KGDB on ARM SMP

[Catalin Marinas]

On Thu, 2010-03-04 at 17:28 +0000, Will Deacon wrote:
> I took a quick look at the code in kernel/kgdb.c and adding the following
> memory barrier appears to resolve the issue:
> 
> diff --git a/kernel/kgdb.c b/kernel/kgdb.c
> index 761fdd2..1308381 100644
> --- a/kernel/kgdb.c
> +++ b/kernel/kgdb.c
> @@ -1537,6 +1537,7 @@ acquirelock:
>                  * Wait till all the CPUs have quit
>                  * from the debugger.
>                  */
> +               smp_wmb();
>                 for_each_online_cpu(i) {
>                         while (atomic_read(&cpu_in_kgdb[i]))
>                                 cpu_relax();

Shouldn't this be smp_rmb()?

-- 
Catalin