On Mon, 4 May 2020 11:37:53 +0300
Denis Kirjanov <[email protected]> wrote:
> +static int xennet_create_page_pool(struct netfront_queue *queue)
> +{
> + int err;
> + struct page_pool_params pp_params = {
> + .order = 0,
> + .flags = 0,
> + .pool_size = NET_RX_RING_SIZE,
> + .nid = NUMA_NO_NODE,
> + .dev = &queue->info->netdev->dev,
> + .offset = XDP_PACKET_HEADROOM,
> + .max_len = XEN_PAGE_SIZE - XDP_PACKET_HEADROOM,
> + };
> +
> + queue->page_pool = page_pool_create(&pp_params);
> + if (IS_ERR(queue->page_pool)) {
> + err = PTR_ERR(queue->page_pool);
> + queue->page_pool = NULL;
> + return err;
> + }
> +
> + err = xdp_rxq_info_reg(&queue->xdp_rxq, queue->info->netdev,
> + queue->id);
> + if (err) {
> + netdev_err(queue->info->netdev, "xdp_rxq_info_reg failed\n");
> + goto err_free_pp;
> + }
> +
> + err = xdp_rxq_info_reg_mem_model(&queue->xdp_rxq,
> + MEM_TYPE_PAGE_ORDER0, NULL);
What!?! - You are creating a page_pool, but registering a MEM_TYPE_PAGE_ORDER0.
Have you even tested this? The page_pool in-flight accounting will be
completely off. This should show up when removing the page_pool again.
For driver developers do diagnose and catch stuff like this, we have
some bpftrace scripts that can help troubleshoot, here[1]:
[1] https://github.com/xdp-project/xdp-project/tree/master/areas/mem/bpftrace
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer
