On Fri, 6 Nov 2020 19:19:07 +0100
Lorenzo Bianconi <lorenzo@xxxxxxxxxx> wrote:
> +void xdp_return_frame_bulk(struct xdp_frame *xdpf,
> + struct xdp_frame_bulk *bq)
> +{
> + struct xdp_mem_info *mem = &xdpf->mem;
> + struct xdp_mem_allocator *xa;
> +
> + if (mem->type != MEM_TYPE_PAGE_POOL) {
> + __xdp_return(xdpf->data, &xdpf->mem, false);
> + return;
> + }
> +
> + rcu_read_lock();
This rcu_read_lock() shows up on my performance benchmarking, and is
unnecessary for the fast-path usage, as in most drivers DMA-TX
completion already holds the rcu_read_lock.
> + xa = bq->xa;
> + if (unlikely(!xa)) {
> + xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params);
> + bq->count = 0;
> + bq->xa = xa;
> + }
> +
> + if (bq->count == XDP_BULK_QUEUE_SIZE)
> + xdp_flush_frame_bulk(bq);
> +
> + if (mem->id != xa->mem.id) {
> + xdp_flush_frame_bulk(bq);
> + bq->xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params);
> + }
> +
> + bq->q[bq->count++] = xdpf->data;
> +
> + rcu_read_unlock();
> +}
> +EXPORT_SYMBOL_GPL(xdp_return_frame_bulk);
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer
