devmap: Adjust tracepoint for map-less queue flush

Now that we don't have a reference to a devmap when flushing the device
bulk queue, let's change the the devmap_xmit tracepoint to remote the
map_id and map_index fields entirely. Rearrange the fields so 'drops' and
'sent' stay in the same position in the tracepoint struct, to make it
possible for the xdp_monitor utility to read both the old and the new
format.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/157918768613.1458396.9165902403373826572.stgit@toke.dk

diff --git a/include/trace/events/xdp.h b/include/trace/events/xdp.h
index b680973..b95d65e 100644 (file)
--- a/include/trace/events/xdp.h
+++ b/include/trace/events/xdp.h
@@ -246,43 +246,38 @@ TRACE_EVENT(xdp_cpumap_enqueue,
 
 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, int err),
+       TP_PROTO(const struct net_device *from_dev,
+                const struct net_device *to_dev,
+                int sent, int drops, int err),
 
-       TP_ARGS(map, map_index, sent, drops, from_dev, to_dev, err),
+       TP_ARGS(from_dev, to_dev, sent, drops, err),
 
        TP_STRUCT__entry(
-               __field(int, map_id)
+               __field(int, from_ifindex)
                __field(u32, act)
-               __field(u32, map_index)
+               __field(int, to_ifindex)
                __field(int, drops)
                __field(int, sent)
-               __field(int, from_ifindex)
-               __field(int, to_ifindex)
                __field(int, err)
        ),
 
        TP_fast_assign(
-               __entry->map_id         = map ? map->id : 0;
+               __entry->from_ifindex   = from_dev->ifindex;
                __entry->act            = XDP_REDIRECT;
-               __entry->map_index      = map_index;
+               __entry->to_ifindex     = to_dev->ifindex;
                __entry->drops          = drops;
                __entry->sent           = sent;
-               __entry->from_ifindex   = from_dev->ifindex;
-               __entry->to_ifindex     = to_dev->ifindex;
                __entry->err            = err;
        ),
 
        TP_printk("ndo_xdp_xmit"
-                 " map_id=%d map_index=%d action=%s"
+                 " from_ifindex=%d to_ifindex=%d action=%s"
                  " sent=%d drops=%d"
-                 " from_ifindex=%d to_ifindex=%d err=%d",
-                 __entry->map_id, __entry->map_index,
+                 " err=%d",
+                 __entry->from_ifindex, __entry->to_ifindex,
                  __print_symbolic(__entry->act, __XDP_ACT_SYM_TAB),
                  __entry->sent, __entry->drops,
-                 __entry->from_ifindex, __entry->to_ifindex, __entry->err)
+                 __entry->err)
 );
 
 /* Expect users already include <net/xdp.h>, but not xdp_priv.h */

diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index d531100..de630f9 100644 (file)
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -340,7 +340,7 @@ static int bq_xmit_all(struct xdp_dev_bulk_queue *bq, u32 flags)
 out:
        bq->count = 0;
 
-       trace_xdp_devmap_xmit(NULL, 0, sent, drops, bq->dev_rx, dev, err);
+       trace_xdp_devmap_xmit(bq->dev_rx, dev, sent, drops, err);
        bq->dev_rx = NULL;
        __list_del_clearprev(&bq->flush_node);
        return 0;

diff --git a/samples/bpf/xdp_monitor_kern.c b/samples/bpf/xdp_monitor_kern.c
index ad10fe7..39458a4 100644 (file)
--- a/samples/bpf/xdp_monitor_kern.c
+++ b/samples/bpf/xdp_monitor_kern.c
@@ -222,14 +222,12 @@ struct bpf_map_def SEC("maps") devmap_xmit_cnt = {
  */
 struct devmap_xmit_ctx {
        u64 __pad;              // First 8 bytes are not accessible by bpf code
-       int map_id;             //      offset:8;  size:4; signed:1;
+       int from_ifindex;       //      offset:8;  size:4; signed:1;
        u32 act;                //      offset:12; size:4; signed:0;
-       u32 map_index;          //      offset:16; size:4; signed:0;
+       int to_ifindex;         //      offset:16; size:4; signed:1;
        int drops;              //      offset:20; size:4; signed:1;
        int sent;               //      offset:24; size:4; signed:1;
-       int from_ifindex;       //      offset:28; size:4; signed:1;
-       int to_ifindex;         //      offset:32; size:4; signed:1;
-       int err;                //      offset:36; size:4; signed:1;
+       int err;                //      offset:28; size:4; signed:1;
 };
 
 SEC("tracepoint/xdp/xdp_devmap_xmit")