Commit 29c1c446 authored by Mubashir Adnan Qureshi's avatar Mubashir Adnan Qureshi Committed by David S. Miller
Browse files

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: default avatarMubashir Adnan Qureshi <mubashirq@google.com>
Signed-off-by: default avatarYuchung Cheng <ycheng@google.com>
Signed-off-by: default avatarNeal Cardwell <ncardwell@google.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c30f8e0b

include/linux/tcp.h

+1 −0
Original line number Diff line number Diff line
@@ -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.

			   */

include/uapi/linux/snmp.h

+1 −0
Original line number Diff line number Diff line
@@ -292,6 +292,7 @@ enum 
	LINUX_MIB_TCPDSACKIGNOREDDUBIOUS,	/* TCPDSACKIgnoredDubious */

	LINUX_MIB_TCPMIGRATEREQSUCCESS,		/* TCPMigrateReqSuccess */

	LINUX_MIB_TCPMIGRATEREQFAILURE,		/* TCPMigrateReqFailure */

	LINUX_MIB_TCPPLBREHASH,			/* TCPPLBRehash */

	__LINUX_MIB_MAX

};

include/uapi/linux/tcp.h

+1 −0
Original line number Diff line number Diff line
@@ -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 */

net/ipv4/proc.c

+1 −0
Original line number Diff line number Diff line
@@ -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

};

net/ipv4/tcp.c

+3 −0
Original line number Diff line number Diff line
@@ -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;

}