tcp: add stat of data packet reordering events
Introduce a new TCP stats to record the number of reordering events seen
and expose it in both tcp_info (TCP_INFO) and opt_stats
(SOF_TIMESTAMPING_OPT_STATS).
Application can use this stats to track the frequency of the reordering
events in addition to the existing reordering stats which tracks the
magnitude of the latest reordering event.
Note: this new stats tracks reordering events triggered by ACKs, which
could often be fewer than the actual number of packets being delivered
out-of-order.
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index da6281c..263e372 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -220,8 +220,7 @@ struct tcp_sock {
#define TCP_RACK_RECOVERY_THRESH 16
u8 reo_wnd_persist:5, /* No. of recovery since last adj */
dsack_seen:1, /* Whether DSACK seen after last adj */
- advanced:1, /* mstamp advanced since last lost marking */
- reord:1; /* reordering detected */
+ advanced:1; /* mstamp advanced since last lost marking */
} rack;
u16 advmss; /* Advertised MSS */
u8 compressed_ack;
@@ -267,6 +266,7 @@ struct tcp_sock {
u8 ecn_flags; /* ECN status bits. */
u8 keepalive_probes; /* num of allowed keep alive probes */
u32 reordering; /* Packet reordering metric. */
+ u32 reord_seen; /* number of data packet reordering events */
u32 snd_up; /* Urgent pointer */
/*