On 06/23/2019 04:17 AM, Toke Høiland-Jørgensen wrote:
> From: Toke Høiland-Jørgensen <t...@redhat.com>
>
> The socket map uses a linked list instead of a bitmap to keep track of
> which entries to flush. Do the same for devmap and cpumap, as this means we
> don't have to care about the map index when enqueueing things into the
> map (and so we can cache the map lookup).
>
> Signed-off-by: Toke Høiland-Jørgensen <t...@redhat.com>
[...]
> +static int bq_flush_to_queue(struct xdp_bulk_queue *bq, bool in_napi_ctx)
> {
> + struct bpf_cpu_map_entry *rcpu = bq->obj;
> unsigned int processed = 0, drops = 0;
> const int to_cpu = rcpu->cpu;
> struct ptr_ring *q;
> @@ -621,6 +630,9 @@ static int bq_flush_to_queue(struct bpf_cpu_map_entry
> *rcpu,
> bq->count = 0;
> spin_unlock(&q->producer_lock);
>
> + __list_del(bq->flush_node.prev, bq->flush_node.next);
> + bq->flush_node.prev = NULL;
Given this and below is a bit non-standard way of using list API, maybe add
these as inline helpers to include/linux/list.h to make sure anyone changing
list API semantics doesn't overlook these in future?
> /* Feedback loop via tracepoints */
> trace_xdp_cpumap_enqueue(rcpu->map_id, processed, drops, to_cpu);
> return 0;
[...]
> +
> + if (!bq->flush_node.prev)
> + list_add(&bq->flush_node, flush_list);
> +
> return 0;
> }
>
