xdp: add tracepoint for devmap like cpumap have

Notice how this allow us get XDP statistic without affecting the XDP
performance, as tracepoint is no-longer activated on a per packet basis.

V5: Spotted by John Fastabend.
 Fix 'sent' also counted 'drops' in this patch, a later patch corrected
 this, but it was a mistake in this intermediate step.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Jesper Dangaard Brouer
2018-05-24 16:45:57 +02:00
committed by Alexei Starovoitov
parent 5d053f9da4
commit 38edddb811
4 changed files with 67 additions and 7 deletions

View File

@@ -58,6 +58,7 @@
#define DEV_MAP_BULK_SIZE 16
struct xdp_bulk_queue {
struct xdp_frame *q[DEV_MAP_BULK_SIZE];
struct net_device *dev_rx;
unsigned int count;
};
@@ -219,6 +220,7 @@ static int bq_xmit_all(struct bpf_dtab_netdev *obj,
struct xdp_bulk_queue *bq)
{
struct net_device *dev = obj->dev;
int sent = 0, drops = 0;
int i;
if (unlikely(!bq->count))
@@ -235,11 +237,18 @@ static int bq_xmit_all(struct bpf_dtab_netdev *obj,
int err;
err = dev->netdev_ops->ndo_xdp_xmit(dev, xdpf);
if (err)
if (err) {
drops++;
xdp_return_frame(xdpf);
} else {
sent++;
}
}
bq->count = 0;
trace_xdp_devmap_xmit(&obj->dtab->map, obj->bit,
sent, drops, bq->dev_rx, dev);
bq->dev_rx = NULL;
return 0;
}
@@ -296,18 +305,28 @@ struct bpf_dtab_netdev *__dev_map_lookup_elem(struct bpf_map *map, u32 key)
/* Runs under RCU-read-side, plus in softirq under NAPI protection.
* Thus, safe percpu variable access.
*/
static int bq_enqueue(struct bpf_dtab_netdev *obj, struct xdp_frame *xdpf)
static int bq_enqueue(struct bpf_dtab_netdev *obj, struct xdp_frame *xdpf,
struct net_device *dev_rx)
{
struct xdp_bulk_queue *bq = this_cpu_ptr(obj->bulkq);
if (unlikely(bq->count == DEV_MAP_BULK_SIZE))
bq_xmit_all(obj, bq);
/* Ingress dev_rx will be the same for all xdp_frame's in
* bulk_queue, because bq stored per-CPU and must be flushed
* from net_device drivers NAPI func end.
*/
if (!bq->dev_rx)
bq->dev_rx = dev_rx;
bq->q[bq->count++] = xdpf;
return 0;
}
int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp)
int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp,
struct net_device *dev_rx)
{
struct net_device *dev = dst->dev;
struct xdp_frame *xdpf;
@@ -319,7 +338,7 @@ int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp)
if (unlikely(!xdpf))
return -EOVERFLOW;
return bq_enqueue(dst, xdpf);
return bq_enqueue(dst, xdpf, dev_rx);
}
static void *dev_map_lookup_elem(struct bpf_map *map, void *key)