On Mon 06-02-17 06:26:41, Matthew Wilcox wrote:
> On Mon, Feb 06, 2017 at 03:07:13PM +0100, Michal Hocko wrote:
> > While we are at it also make sure that the radix tree doesn't
> > accidentaly override tags stored in the upper part of the gfp_mask.
>
> > diff --git a/lib/radix-tree.c b/lib/radix-tree.c
> > index 9dc093d5ef39..7550be09f9d6 100644
> > --- a/lib/radix-tree.c
> > +++ b/lib/radix-tree.c
> > @@ -2274,6 +2274,8 @@ static int radix_tree_cpu_dead(unsigned int cpu)
> > void __init radix_tree_init(void)
> > {
> > int ret;
> > +
> > + BUILD_BUG_ON(RADIX_TREE_MAX_TAGS + __GFP_BITS_SHIFT > 32);
> > radix_tree_node_cachep = kmem_cache_create("radix_tree_node",
> > sizeof(struct radix_tree_node), 0,
> > SLAB_PANIC | SLAB_RECLAIM_ACCOUNT,
>
> That's going to have a conceptual conflict with some patches I have
> in flight. I'll take this part through my radix tree patch collection.
This part is not needed for the patch, strictly speaking but I wanted to
make the code more future proof.
--
Michal Hocko
SUSE Labs
