Re: [PATCH] slub: always align cpu_slab to honor cmpxchg_doublerequirement

From: David Rientjes
Date: Thu Jun 02 2011 - 13:16:41 EST


On Thu, 2 Jun 2011, Chris Metcalf wrote:

> On an architecture without CMPXCHG_LOCAL but with DEBUG_VM enabled,
> the VM_BUG_ON() in __pcpu_double_call_return_bool() will cause an early
> panic during boot unless we always align cpu_slab properly.
>
> In principle we could remove the alignment-testing VM_BUG_ON() for
> architectures that don't have CMPXCHG_LOCAL, but leaving it in means
> that new code will tend not to break x86 even if it is introduced
> on another platform, and it's low cost to require alignment.
>
> Signed-off-by: Chris Metcalf <cmetcalf@xxxxxxxxxx>

Acked-by: David Rientjes <rientjes@xxxxxxxxxx>

> ---
> This needs to be pushed for 3.0 to allow arch/tile to boot.
> I'm happy to push it but I assume it would be better coming
> from an mm or percpu tree. Thanks!
>

Should also be marked for stable for 2.6.39.x, right?
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/