Re: [PATCH v3 2/9] slab: move up code to get kmem_cache_node in free_block()

[Joonsoo Kim]

On Tue, Jul 01, 2014 at 03:21:21PM -0700, David Rientjes wrote:
> On Tue, 1 Jul 2014, Joonsoo Kim wrote:
> 
> > node isn't changed, so we don't need to retreive this structure
> > everytime we move the object. Maybe compiler do this optimization,
> > but making it explicitly is better.
> > 
> 
> Qualifying the pointer as const would be even more explicit.

Hello,

So what you recommend is something likes below?

-       struct kmem_cache_node *n = get_node(cachep, node);
+       struct kmem_cache_node * const n = get_node(cachep, node);

I don't have seen this form of code protecting pointer itself in mm.
Instead, I have seen 'const struct kmem_cache_node *n' which protects
memory pointed by pointer. But this case isn't that case.

Am I missing something?

> 
> > Acked-by: Christoph Lameter <cl@xxxxxxxxx>
> > Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
> 
> Acked-by: David Rientjes <rientjes@xxxxxxxxxx>

Thank you!

--
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/