On Fri, Oct 11, 2013 at 3:55 PM, Andy Zhou <[email protected]> wrote:
> diff --git a/datapath/datapath.c b/datapath/datapath.c
> index 9e6df12..859a3b1 100644
> --- a/datapath/datapath.c
> +++ b/datapath/datapath.c
> +static void get_dp_megaflow_stats(struct datapath *dp,
> + struct ovs_dp_megaflow_stats *stats)
> +{
Could we have get_dp_stats() return this information as well? It seems
like that would eliminate a lot of the boilerplate per-cpu collection
code.
> +static struct sw_flow *ovs_flow_tbl_lookup__ (struct flow_table *tbl,
> + const struct sw_flow_key *key)
> +{
> + u32 __attribute__((unused)) n_mask_hit;
There's a kernel macro that you could use here - __always_unused.
> diff --git a/datapath/datapath.h b/datapath/datapath.h
> index 64920de..ae4975d 100644
> --- a/datapath/datapath.h
> +++ b/datapath/datapath.h
> @@ -48,11 +48,16 @@
> * @n_lost: Number of received packets that had no matching flow in the flow
> * table that could not be sent to userspace (normally due to an overflow in
> * one of the datapath's queues).
> + * @n_mask_hit: Number of masks looked up for flow match.
> + * (@n_hit + @n_missed) / @n_mask_hit will be the average masks looked up per
> + * packet.
Should the numerator and denominator be reversed in this comment?
> diff --git a/datapath/flow_table.c b/datapath/flow_table.c
> index 98eb809..367befe 100644
> --- a/datapath/flow_table.c
> +++ b/datapath/flow_table.c
> @@ -422,6 +423,7 @@ static struct sw_flow *masked_flow_lookup(struct
> table_instance *ti,
> hash = flow_hash(&masked_key, key_start, key_end);
> head = find_bucket(ti, hash);
> hlist_for_each_entry_rcu(flow, head, hash_node[ti->node_ver]) {
> + (*n_mask_hit)++;
> if (flow->mask == mask &&
> flow_cmp_masked_key(flow, &masked_key,
> key_start, key_end))
This surprised me because it includes the number of hash collisions in
addition to the mask lookups. Obviously collisions impact performance
as well but it's not what I would intuitively expect to get from this
stat.
> +int ovs_flow_tbl_num_masks(const struct flow_table *table)
> +{
> + struct sw_flow_mask *mask;
> + int num = 0;
> +
> + list_for_each_entry(mask, &table->mask_list, list)
> + num++;
> +
> + return num;
> +}
> +
> +
Extra blank line here.
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