Re: [patch 3/9] radix-tree: gang slot lookups

[Peter Zijlstra <peterz@infradead.org>]

On Thu, 2007-04-12 at 14:45 +0200, Nick Piggin wrote:

> @@ -825,13 +889,21 @@ radix_tree_gang_lookup_tag(struct radix_
>  
>  	ret = 0;
>  	while (ret < max_items) {
> -		unsigned int nr_found;
> +		unsigned int slots_found, nr_found, i;
>  		unsigned long next_index;	/* Index of next search */
>  
>  		if (cur_index > max_index)
>  			break;
> -		nr_found = __lookup_tag(node, results + ret, cur_index,
> -					max_items - ret, &next_index, tag);
> +		slots_found = __lookup_tag(node, (void ***)results + ret,
> +				cur_index, max_items - ret, &next_index, tag);
> +		nr_found = 0;
> +		for (i = 0; i < slots_found; i++) {
> +			node = *((void ***)results)[ret + i];
> +			if (!node)
> +				continue;
> +			results[ret + nr_found] = rcu_dereference(node);

I think this should read (as you correctly did in
radix_tree_gang_lookup):

			struct radix_tree_node *slot;
			slot = *((void ***)results)[ret + i];
			if (!slot)
				continue;
			results[ret + nr_found] = rcu_dereference(slot);

by overwriting node, a subsequent __lookup_tag() will do the darnest
things.


> +			nr_found++;
> +		}
>  		ret += nr_found;
>  		if (next_index == 0)
>  			break;



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