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authorWei Wang <weiwan@google.com>2018-08-01 03:46:24 +0300
committerDavid S. Miller <davem@davemloft.net>2018-08-01 19:56:10 +0300
commit7ec65372ca534217b53fd208500cf7aac223a383 (patch)
tree5debcce08aca141b24d1a5c9875d73cae07f3394 /net
parent7e10b6554ff2ce7f86d5d3eec3af5db8db482caa (diff)
downloadlinux-7ec65372ca534217b53fd208500cf7aac223a383.tar.xz
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>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/tcp.c4
-rw-r--r--net/ipv4/tcp_input.c3
-rw-r--r--net/ipv4/tcp_recovery.c2
3 files changed, 7 insertions, 2 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index d6232b598cae..31fa1c080f28 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2597,6 +2597,7 @@ int tcp_disconnect(struct sock *sk, int flags)
tp->bytes_sent = 0;
tp->bytes_retrans = 0;
tp->dsack_dups = 0;
+ tp->reord_seen = 0;
/* Clean up fastopen related fields */
tcp_free_fastopen_req(tp);
@@ -3207,6 +3208,7 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info)
info->tcpi_bytes_sent = tp->bytes_sent;
info->tcpi_bytes_retrans = tp->bytes_retrans;
info->tcpi_dsack_dups = tp->dsack_dups;
+ info->tcpi_reord_seen = tp->reord_seen;
unlock_sock_fast(sk, slow);
}
EXPORT_SYMBOL_GPL(tcp_get_info);
@@ -3234,6 +3236,7 @@ static size_t tcp_opt_stats_get_size(void)
nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_BYTES_SENT */
nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_BYTES_RETRANS */
nla_total_size(sizeof(u32)) + /* TCP_NLA_DSACK_DUPS */
+ nla_total_size(sizeof(u32)) + /* TCP_NLA_REORD_SEEN */
0;
}
@@ -3286,6 +3289,7 @@ struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk)
nla_put_u64_64bit(stats, TCP_NLA_BYTES_RETRANS, tp->bytes_retrans,
TCP_NLA_PAD);
nla_put_u32(stats, TCP_NLA_DSACK_DUPS, tp->dsack_dups);
+ nla_put_u32(stats, TCP_NLA_REORD_SEEN, tp->reord_seen);
return stats;
}
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index fbc85ff7d71d..3d6156f07a8d 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -906,8 +906,8 @@ static void tcp_check_sack_reordering(struct sock *sk, const u32 low_seq,
sock_net(sk)->ipv4.sysctl_tcp_max_reordering);
}
- tp->rack.reord = 1;
/* This exciting event is worth to be remembered. 8) */
+ tp->reord_seen++;
NET_INC_STATS(sock_net(sk),
ts ? LINUX_MIB_TCPTSREORDER : LINUX_MIB_TCPSACKREORDER);
}
@@ -1871,6 +1871,7 @@ static void tcp_check_reno_reordering(struct sock *sk, const int addend)
tp->reordering = min_t(u32, tp->packets_out + addend,
sock_net(sk)->ipv4.sysctl_tcp_max_reordering);
+ tp->reord_seen++;
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPRENOREORDER);
}
diff --git a/net/ipv4/tcp_recovery.c b/net/ipv4/tcp_recovery.c
index 71593e4400ab..c81aadff769b 100644
--- a/net/ipv4/tcp_recovery.c
+++ b/net/ipv4/tcp_recovery.c
@@ -25,7 +25,7 @@ static u32 tcp_rack_reo_wnd(const struct sock *sk)
{
struct tcp_sock *tp = tcp_sk(sk);
- if (!tp->rack.reord) {
+ if (!tp->reord_seen) {
/* If reordering has not been observed, be aggressive during
* the recovery or starting the recovery by DUPACK threshold.
*/