[PATCH bpf-next 4/4] samples/bpf: xdpsock: add time-out for cleaning Tx

[Ong Boon Leong <boon.leong.ong@xxxxxxxxx>]

When user sets tx-pkt-count and in case where there are invalid Tx frame,
the complete_tx_only_all() process polls indefinitely. So, this patch
adds a time-out mechanism into the process so that the application
can terminate automatically after it retries 3*polling interval duration.

 sock0@enp0s29f1:2 txonly xdp-drv
                   pps            pkts           1.00
rx                 0              0
tx                 136383         1000000
rx dropped         0              0
rx invalid         0              0
tx invalid         35             245
rx queue full      0              0
fill ring empty    0              1
tx ring empty      957            7011

 sock0@enp0s29f1:2 txonly xdp-drv
                   pps            pkts           1.00
rx                 0              0
tx                 0              1000000
rx dropped         0              0
rx invalid         0              0
tx invalid         0              245
rx queue full      0              0
fill ring empty    0              1
tx ring empty      1              7012

 sock0@enp0s29f1:2 txonly xdp-drv
                   pps            pkts           1.00
rx                 0              0
tx                 0              1000000
rx dropped         0              0
rx invalid         0              0
tx invalid         0              245
rx queue full      0              0
fill ring empty    0              1
tx ring empty      1              7013

 sock0@enp0s29f1:2 txonly xdp-drv
                   pps            pkts           1.00
rx                 0              0
tx                 0              1000000
rx dropped         0              0
rx invalid         0              0
tx invalid         0              245
rx queue full      0              0
fill ring empty    0              1
tx ring empty      1              7014

 sock0@enp0s29f1:2 txonly xdp-drv
                   pps            pkts           1.00
rx                 0              0
tx                 0              1000000
rx dropped         0              0
rx invalid         0              0
tx invalid         0              245
rx queue full      0              0
fill ring empty    0              1
tx ring empty      0              7014

 sock0@enp0s29f1:2 txonly xdp-drv
                   pps            pkts           0.00
rx                 0              0
tx                 0              1000000
rx dropped         0              0
rx invalid         0              0
tx invalid         0              245
rx queue full      0              0
fill ring empty    0              1
tx ring empty      0              7014

Signed-off-by: Ong Boon Leong <boon.leong.ong@xxxxxxxxx>
---
 samples/bpf/xdpsock_user.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c
index 61d4063f11a..9c3311329ec 100644
--- a/samples/bpf/xdpsock_user.c
+++ b/samples/bpf/xdpsock_user.c
@@ -1410,6 +1410,7 @@ static inline int get_batch_size(int pkt_cnt)
 
 static void complete_tx_only_all(void)
 {
+	u32 retries = 3;
 	bool pending;
 	int i;
 
@@ -1421,7 +1422,8 @@ static void complete_tx_only_all(void)
 				pending = !!xsks[i]->outstanding_tx;
 			}
 		}
-	} while (pending);
+		sleep(opt_interval);
+	} while (pending && retries-- > 0);
 }
 
 static void tx_only_all(void)
-- 
2.25.1