Commit 0ebab78c authored by Lorenzo Bianconi's avatar Lorenzo Bianconi Committed by Jakub Kicinski
Browse files

net: veth: add page_pool for page recycling 



Introduce page_pool support in veth driver in order to recycle pages
in veth_convert_skb_to_xdp_buff routine and avoid reallocating the skb
through the page allocator.
The patch has been tested sending tcp traffic to a veth pair where the
remote peer is running a simple xdp program just returning xdp_pass:

veth upstream codebase:
MTU 1500B: ~ 8Gbps
MTU 8000B: ~ 13.9Gbps

veth upstream codebase + pp support:
MTU 1500B: ~ 9.2Gbps
MTU 8000B: ~ 16.2Gbps

Tested-by: default avatarMaryam Tahhan <mtahhan@redhat.com>
Signed-off-by: default avatarLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent ffcddcae

drivers/net/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -402,6 +402,7 @@ config TUN_VNET_CROSS_LE 


config VETH

	tristate "Virtual ethernet pair device"

	select PAGE_POOL

	help

	  This device is a local ethernet tunnel. Devices are created in pairs.

	  When one end receives the packet it appears on its pair and vice

drivers/net/veth.c

+44 −4
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ 
#include <linux/ptr_ring.h>

#include <linux/bpf_trace.h>

#include <linux/net_tstamp.h>

#include <net/page_pool.h>



#define DRV_NAME	"veth"

#define DRV_VERSION	"1.0"
@@ -65,6 +66,7 @@ struct veth_rq { 
	bool			rx_notify_masked;

	struct ptr_ring		xdp_ring;

	struct xdp_rxq_info	xdp_rxq;

	struct page_pool	*page_pool;

};



struct veth_priv {
@@ -727,17 +729,20 @@ static int veth_convert_skb_to_xdp_buff(struct veth_rq *rq, 
			goto drop;



		/* Allocate skb head */

		page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);

		page = page_pool_dev_alloc_pages(rq->page_pool);

		if (!page)

			goto drop;



		nskb = build_skb(page_address(page), PAGE_SIZE);

		if (!nskb) {

			put_page(page);

			page_pool_put_full_page(rq->page_pool, page, true);

			goto drop;

		}



		skb_reserve(nskb, VETH_XDP_HEADROOM);

		skb_copy_header(nskb, skb);

		skb_mark_for_recycle(nskb);



		size = min_t(u32, skb->len, max_head_size);

		if (skb_copy_bits(skb, 0, nskb->data, size)) {

			consume_skb(nskb);
@@ -745,7 +750,6 @@ static int veth_convert_skb_to_xdp_buff(struct veth_rq *rq, 
		}

		skb_put(nskb, size);



		skb_copy_header(nskb, skb);

		head_off = skb_headroom(nskb) - skb_headroom(skb);

		skb_headers_offset_update(nskb, head_off);
@@ -754,7 +758,7 @@ static int veth_convert_skb_to_xdp_buff(struct veth_rq *rq, 
		len = skb->len - off;



		for (i = 0; i < MAX_SKB_FRAGS && off < skb->len; i++) {

			page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);

			page = page_pool_dev_alloc_pages(rq->page_pool);

			if (!page) {

				consume_skb(nskb);

				goto drop;
@@ -1002,11 +1006,37 @@ static int veth_poll(struct napi_struct *napi, int budget) 
	return done;

}



static int veth_create_page_pool(struct veth_rq *rq)

{

	struct page_pool_params pp_params = {

		.order = 0,

		.pool_size = VETH_RING_SIZE,

		.nid = NUMA_NO_NODE,

		.dev = &rq->dev->dev,

	};



	rq->page_pool = page_pool_create(&pp_params);

	if (IS_ERR(rq->page_pool)) {

		int err = PTR_ERR(rq->page_pool);



		rq->page_pool = NULL;

		return err;

	}



	return 0;

}



static int __veth_napi_enable_range(struct net_device *dev, int start, int end)

{

	struct veth_priv *priv = netdev_priv(dev);

	int err, i;



	for (i = start; i < end; i++) {

		err = veth_create_page_pool(&priv->rq[i]);

		if (err)

			goto err_page_pool;

	}



	for (i = start; i < end; i++) {

		struct veth_rq *rq = &priv->rq[i];
@@ -1027,6 +1057,11 @@ static int __veth_napi_enable_range(struct net_device *dev, int start, int end) 
err_xdp_ring:

	for (i--; i >= start; i--)

		ptr_ring_cleanup(&priv->rq[i].xdp_ring, veth_ptr_free);

err_page_pool:

	for (i = start; i < end; i++) {

		page_pool_destroy(priv->rq[i].page_pool);

		priv->rq[i].page_pool = NULL;

	}



	return err;

}
@@ -1056,6 +1091,11 @@ static void veth_napi_del_range(struct net_device *dev, int start, int end) 
		rq->rx_notify_masked = false;

		ptr_ring_cleanup(&rq->xdp_ring, veth_ptr_free);

	}



	for (i = start; i < end; i++) {

		page_pool_destroy(priv->rq[i].page_pool);

		priv->rq[i].page_pool = NULL;

	}

}



static void veth_napi_del(struct net_device *dev)