xsk: Add new statistics

It can be useful for the user to know the reason behind a dropped packet.
Introduce new counters which track drops on the receive path caused by:
1. rx ring being full
2. fill ring being empty

Also, on the tx path introduce a counter which tracks the number of times
we attempt pull from the tx ring when it is empty.

Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200708072835.4427-2-ciara.loftus@intel.com

1 files changed, 6 insertions, 0 deletions

diff --git a/net/xdp/xsk_queue.h b/net/xdp/xsk_queue.h
index 5b5d24d2dd37..bf42cfd74b89 100644
--- a/net/xdp/xsk_queue.h
+++ b/net/xdp/xsk_queue.h
@@ -38,6 +38,7 @@ struct xsk_queue {
 	u32 cached_cons;
 	struct xdp_ring *ring;
 	u64 invalid_descs;
+	u64 queue_empty_descs;
 };
 
 /* The structure of the shared state of the rings are the same as the
@@ -354,6 +355,11 @@ static inline u64 xskq_nb_invalid_descs(struct xsk_queue *q)
 	return q ? q->invalid_descs : 0;
 }
 
+static inline u64 xskq_nb_queue_empty_descs(struct xsk_queue *q)
+{
+	return q ? q->queue_empty_descs : 0;
+}
+
 struct xsk_queue *xskq_create(u32 nentries, bool umem_queue);
 void xskq_destroy(struct xsk_queue *q_ops);