Split ndo_xdp_xmit and ndo_start_xmit use cases in veth_xdp_rcv routine
in order to alloc skbs in bulk for XDP_PASS verdict.
Introduce xdp_alloc_skb_bulk utility routine to alloc skb bulk list.
The proposed approach has been tested in the following scenario:
eth (ixgbe) --> XDP_REDIRECT --> veth0 --> (remote-ns) veth1 --> XDP_PASS
XDP_REDIRECT: xdp_redirect_map bpf sample
XDP_PASS: xdp_rxq_info bpf sample
traffic generator: pkt_gen sending udp traffic on a remote device
bpf-next master: ~3.64Mpps
bpf-next + skb bulking allocation: ~3.79Mpps
Signed-off-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx>
---
Changes since v2:
- use __GFP_ZERO flag instead of memset
- move some veth_xdp_rcv_batch() logic in veth_xdp_rcv_skb()
Changes since v1:
- drop patch 2/3, squash patch 1/3 and 3/3
- set VETH_XDP_BATCH to 16
- rework veth_xdp_rcv to use __ptr_ring_consume
---
drivers/net/veth.c | 78 ++++++++++++++++++++++++++++++++++------------
include/net/xdp.h | 1 +
net/core/xdp.c | 11 +++++++
3 files changed, 70 insertions(+), 20 deletions(-)
diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index 6e03b619c93c..aa1a66ad2ce5 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -35,6 +35,7 @@
#define VETH_XDP_HEADROOM (XDP_PACKET_HEADROOM + NET_IP_ALIGN)
#define VETH_XDP_TX_BULK_SIZE 16
+#define VETH_XDP_BATCH 16
struct veth_stats {
u64 rx_drops;
@@ -562,14 +563,13 @@ static int veth_xdp_tx(struct veth_rq *rq, struct xdp_buff *xdp,
return 0;
}
-static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq,
- struct xdp_frame *frame,
- struct veth_xdp_tx_bq *bq,
- struct veth_stats *stats)
+static struct xdp_frame *veth_xdp_rcv_one(struct veth_rq *rq,
+ struct xdp_frame *frame,
+ struct veth_xdp_tx_bq *bq,
+ struct veth_stats *stats)
{
struct xdp_frame orig_frame;
struct bpf_prog *xdp_prog;
- struct sk_buff *skb;
rcu_read_lock();
xdp_prog = rcu_dereference(rq->xdp_prog);
@@ -623,13 +623,7 @@ static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq,
}
rcu_read_unlock();
- skb = xdp_build_skb_from_frame(frame, rq->dev);
- if (!skb) {
- xdp_return_frame(frame);
- stats->rx_drops++;
- }
-
- return skb;
+ return frame;
err_xdp:
rcu_read_unlock();
xdp_return_frame(frame);
@@ -637,6 +631,37 @@ static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq,
return NULL;
}
+/* frames array contains VETH_XDP_BATCH at most */
+static void veth_xdp_rcv_bulk_skb(struct veth_rq *rq, void **frames,
+ int n_xdpf, struct veth_xdp_tx_bq *bq,
+ struct veth_stats *stats)
+{
+ void *skbs[VETH_XDP_BATCH];
+ int i;
+
+ if (xdp_alloc_skb_bulk(skbs, n_xdpf,
+ GFP_ATOMIC | __GFP_ZERO) < 0) {
+ for (i = 0; i < n_xdpf; i++)
+ xdp_return_frame(frames[i]);
+ stats->rx_drops += n_xdpf;
+
+ return;
+ }
+
+ for (i = 0; i < n_xdpf; i++) {
+ struct sk_buff *skb = skbs[i];
+
+ skb = __xdp_build_skb_from_frame(frames[i], skb,
+ rq->dev);
+ if (!skb) {
+ xdp_return_frame(frames[i]);
+ stats->rx_drops++;
+ continue;
+ }
+ napi_gro_receive(&rq->xdp_napi, skb);
+ }
+}
+
static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq,
struct sk_buff *skb,
struct veth_xdp_tx_bq *bq,
@@ -784,32 +809,45 @@ static int veth_xdp_rcv(struct veth_rq *rq, int budget,
struct veth_xdp_tx_bq *bq,
struct veth_stats *stats)
{
- int i, done = 0;
+ int i, done = 0, n_xdpf = 0;
+ void *xdpf[VETH_XDP_BATCH];
for (i = 0; i < budget; i++) {
void *ptr = __ptr_ring_consume(&rq->xdp_ring);
- struct sk_buff *skb;
if (!ptr)
break;
if (veth_is_xdp_frame(ptr)) {
+ /* ndo_xdp_xmit */
struct xdp_frame *frame = veth_ptr_to_xdp(ptr);
stats->xdp_bytes += frame->len;
- skb = veth_xdp_rcv_one(rq, frame, bq, stats);
+ frame = veth_xdp_rcv_one(rq, frame, bq, stats);
+ if (frame) {
+ /* XDP_PASS */
+ xdpf[n_xdpf++] = frame;
+ if (n_xdpf == VETH_XDP_BATCH) {
+ veth_xdp_rcv_bulk_skb(rq, xdpf, n_xdpf,
+ bq, stats);
+ n_xdpf = 0;
+ }
+ }
} else {
- skb = ptr;
+ /* ndo_start_xmit */
+ struct sk_buff *skb = ptr;
+
stats->xdp_bytes += skb->len;
skb = veth_xdp_rcv_skb(rq, skb, bq, stats);
+ if (skb)
+ napi_gro_receive(&rq->xdp_napi, skb);
}
-
- if (skb)
- napi_gro_receive(&rq->xdp_napi, skb);
-
done++;
}
+ if (n_xdpf)
+ veth_xdp_rcv_bulk_skb(rq, xdpf, n_xdpf, bq, stats);
+
u64_stats_update_begin(&rq->stats.syncp);
rq->stats.vs.xdp_redirect += stats->xdp_redirect;
rq->stats.vs.xdp_bytes += stats->xdp_bytes;
diff --git a/include/net/xdp.h b/include/net/xdp.h
index c4bfdc9a8b79..a5bc214a49d9 100644
--- a/include/net/xdp.h
+++ b/include/net/xdp.h
@@ -169,6 +169,7 @@ struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf,
struct net_device *dev);
struct sk_buff *xdp_build_skb_from_frame(struct xdp_frame *xdpf,
struct net_device *dev);
+int xdp_alloc_skb_bulk(void **skbs, int n_skb, gfp_t gfp);
static inline
void xdp_convert_frame_to_buff(struct xdp_frame *frame, struct xdp_buff *xdp)
diff --git a/net/core/xdp.c b/net/core/xdp.c
index 0d2630a35c3e..05354976c1fc 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c
@@ -514,6 +514,17 @@ void xdp_warn(const char *msg, const char *func, const int line)
};
EXPORT_SYMBOL_GPL(xdp_warn);
+int xdp_alloc_skb_bulk(void **skbs, int n_skb, gfp_t gfp)
+{
+ n_skb = kmem_cache_alloc_bulk(skbuff_head_cache, gfp,
+ n_skb, skbs);
+ if (unlikely(!n_skb))
+ return -ENOMEM;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(xdp_alloc_skb_bulk);
+
struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf,
struct sk_buff *skb,
struct net_device *dev)
--
2.29.2
