tcp: add u32 counter in tcp_sock and an SNMP counter for PLB

A u32 counter is added to tcp_sock for counting the number of PLB
triggered rehashes for a TCP connection. An SNMP counter is also
added to count overall PLB triggered rehash events for a host. These
counters are hooked up to PLB implementation for DCTCP.

TCP_NLA_REHASH is added to SCM_TIMESTAMPING_OPT_STATS that reports
the rehash attempts triggered due to PLB or timeouts. This gives
a historical view of sustained congestion or timeouts experienced
by the TCP connection.

Signed-off-by: Mubashir Adnan Qureshi <mubashirq@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Mubashir Adnan Qureshi 2022-10-26 13:51:14 +00:00 committed by David S. Miller
parent c30f8e0b04
commit 29c1c44646
6 changed files with 9 additions and 0 deletions

View File

@ -423,6 +423,7 @@ struct tcp_sock {
u32 probe_seq_start;
u32 probe_seq_end;
} mtu_probe;
u32 plb_rehash; /* PLB-triggered rehash attempts */
u32 mtu_info; /* We received an ICMP_FRAG_NEEDED / ICMPV6_PKT_TOOBIG
* while socket was owned by user.
*/

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@ -292,6 +292,7 @@ enum
LINUX_MIB_TCPDSACKIGNOREDDUBIOUS, /* TCPDSACKIgnoredDubious */
LINUX_MIB_TCPMIGRATEREQSUCCESS, /* TCPMigrateReqSuccess */
LINUX_MIB_TCPMIGRATEREQFAILURE, /* TCPMigrateReqFailure */
LINUX_MIB_TCPPLBREHASH, /* TCPPLBRehash */
__LINUX_MIB_MAX
};

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@ -315,6 +315,7 @@ enum {
TCP_NLA_BYTES_NOTSENT, /* Bytes in write queue not yet sent */
TCP_NLA_EDT, /* Earliest departure time (CLOCK_MONOTONIC) */
TCP_NLA_TTL, /* TTL or hop limit of a packet received */
TCP_NLA_REHASH, /* PLB and timeout triggered rehash attempts */
};
/* for TCP_MD5SIG socket option */

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@ -297,6 +297,7 @@ static const struct snmp_mib snmp4_net_list[] = {
SNMP_MIB_ITEM("TCPDSACKIgnoredDubious", LINUX_MIB_TCPDSACKIGNOREDDUBIOUS),
SNMP_MIB_ITEM("TCPMigrateReqSuccess", LINUX_MIB_TCPMIGRATEREQSUCCESS),
SNMP_MIB_ITEM("TCPMigrateReqFailure", LINUX_MIB_TCPMIGRATEREQFAILURE),
SNMP_MIB_ITEM("TCPPLBRehash", LINUX_MIB_TCPPLBREHASH),
SNMP_MIB_SENTINEL
};

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@ -3176,6 +3176,7 @@ int tcp_disconnect(struct sock *sk, int flags)
tp->sacked_out = 0;
tp->tlp_high_seq = 0;
tp->last_oow_ack_time = 0;
tp->plb_rehash = 0;
/* There's a bubble in the pipe until at least the first ACK. */
tp->app_limited = ~0U;
tp->rack.mstamp = 0;
@ -3973,6 +3974,7 @@ static size_t tcp_opt_stats_get_size(void)
nla_total_size(sizeof(u32)) + /* TCP_NLA_BYTES_NOTSENT */
nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_EDT */
nla_total_size(sizeof(u8)) + /* TCP_NLA_TTL */
nla_total_size(sizeof(u32)) + /* TCP_NLA_REHASH */
0;
}
@ -4049,6 +4051,7 @@ struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk,
nla_put_u8(stats, TCP_NLA_TTL,
tcp_skb_ttl_or_hop_limit(ack_skb));
nla_put_u32(stats, TCP_NLA_REHASH, tp->plb_rehash + tp->timeout_rehash);
return stats;
}

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@ -79,6 +79,8 @@ void tcp_plb_check_rehash(struct sock *sk, struct tcp_plb_state *plb)
sk_rethink_txhash(sk);
plb->consec_cong_rounds = 0;
tcp_sk(sk)->plb_rehash++;
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPPLBREHASH);
}
EXPORT_SYMBOL_GPL(tcp_plb_check_rehash);