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authorJesper Dangaard Brouer <brouer@redhat.com>2018-05-24 16:45:57 +0200
committerAlexei Starovoitov <ast@kernel.org>2018-05-24 18:36:15 -0700
commit38edddb81172e8b8decb057c0cd23271583a5fa0 (patch)
tree444ebbb5e686501073401c5836712b819ef03e10
parent5d053f9da4311a86bc58be8588bb5660fb3f0724 (diff)
downloadlinux-38edddb81172e8b8decb057c0cd23271583a5fa0.tar.bz2
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>
-rw-r--r--include/linux/bpf.h6
-rw-r--r--include/trace/events/xdp.h39
-rw-r--r--kernel/bpf/devmap.c27
-rw-r--r--net/core/filter.c2
4 files changed, 67 insertions, 7 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 23a809da452d..bbe297436e5d 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -492,7 +492,8 @@ struct xdp_buff;
struct bpf_dtab_netdev *__dev_map_lookup_elem(struct bpf_map *map, u32 key);
void __dev_map_insert_ctx(struct bpf_map *map, u32 index);
void __dev_map_flush(struct bpf_map *map);
-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 bpf_cpu_map_entry *__cpu_map_lookup_elem(struct bpf_map *map, u32 key);
void __cpu_map_insert_ctx(struct bpf_map *map, u32 index);
@@ -579,7 +580,8 @@ struct xdp_buff;
struct bpf_dtab_netdev;
static inline
-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)
{
return 0;
}
diff --git a/include/trace/events/xdp.h b/include/trace/events/xdp.h
index 96104610d40e..2e9ef0650144 100644
--- a/include/trace/events/xdp.h
+++ b/include/trace/events/xdp.h
@@ -229,6 +229,45 @@ TRACE_EVENT(xdp_cpumap_enqueue,
__entry->to_cpu)
);
+TRACE_EVENT(xdp_devmap_xmit,
+
+ TP_PROTO(const struct bpf_map *map, u32 map_index,
+ int sent, int drops,
+ const struct net_device *from_dev,
+ const struct net_device *to_dev),
+
+ TP_ARGS(map, map_index, sent, drops, from_dev, to_dev),
+
+ TP_STRUCT__entry(
+ __field(int, map_id)
+ __field(u32, act)
+ __field(u32, map_index)
+ __field(int, drops)
+ __field(int, sent)
+ __field(int, from_ifindex)
+ __field(int, to_ifindex)
+ ),
+
+ TP_fast_assign(
+ __entry->map_id = map->id;
+ __entry->act = XDP_REDIRECT;
+ __entry->map_index = map_index;
+ __entry->drops = drops;
+ __entry->sent = sent;
+ __entry->from_ifindex = from_dev->ifindex;
+ __entry->to_ifindex = to_dev->ifindex;
+ ),
+
+ TP_printk("ndo_xdp_xmit"
+ " map_id=%d map_index=%d action=%s"
+ " sent=%d drops=%d"
+ " from_ifindex=%d to_ifindex=%d",
+ __entry->map_id, __entry->map_index,
+ __print_symbolic(__entry->act, __XDP_ACT_SYM_TAB),
+ __entry->sent, __entry->drops,
+ __entry->from_ifindex, __entry->to_ifindex)
+);
+
#endif /* _TRACE_XDP_H */
#include <trace/define_trace.h>
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index 15293b9dfb77..ff2f3bf59f2f 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -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)
diff --git a/net/core/filter.c b/net/core/filter.c
index c867106d3707..36cf2f87d742 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -3067,7 +3067,7 @@ static int __bpf_tx_xdp_map(struct net_device *dev_rx, void *fwd,
case BPF_MAP_TYPE_DEVMAP: {
struct bpf_dtab_netdev *dst = fwd;
- err = dev_map_enqueue(dst, xdp);
+ err = dev_map_enqueue(dst, xdp, dev_rx);
if (err)
return err;
__dev_map_insert_ctx(map, index);