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| author | Soheil Hassas Yeganeh <soheil@google.com> | 2019-03-22 10:59:47 -0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-03-23 21:50:05 -0400 |
| commit | 576fd2f7cac3daa36025f0039f9e7cb75b4b4ae0 (patch) | |
| tree | c93566c3a3ef72fd17dfb821bce213397c63ff2d | |
| parent | e6d1407013a91722ffc89e980d715eb9ce7b57f6 (diff) | |
| download | linux-576fd2f7cac3daa36025f0039f9e7cb75b4b4ae0.tar.gz linux-576fd2f7cac3daa36025f0039f9e7cb75b4b4ae0.tar.bz2 linux-576fd2f7cac3daa36025f0039f9e7cb75b4b4ae0.zip | |
tcp: add documentation for tcp_ca_state
Add documentation to the tcp_ca_state enum, since this enum is
exposed in uapi.
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Sowmini Varadhan <sowmini05@gmail.com>
Acked-by: Sowmini Varadhan <sowmini05@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/uapi/linux/tcp.h | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h index 8bb6cc5f3235..b521464ea962 100644 --- a/include/uapi/linux/tcp.h +++ b/include/uapi/linux/tcp.h @@ -160,15 +160,42 @@ enum { #define TCPI_OPT_ECN_SEEN 16 /* we received at least one packet with ECT */ #define TCPI_OPT_SYN_DATA 32 /* SYN-ACK acked data in SYN sent or rcvd */ +/* + * Sender's congestion state indicating normal or abnormal situations + * in the last round of packets sent. The state is driven by the ACK + * information and timer events. + */ enum tcp_ca_state { + /* + * Nothing bad has been observed recently. + * No apparent reordering, packet loss, or ECN marks. + */ TCP_CA_Open = 0, #define TCPF_CA_Open (1<<TCP_CA_Open) + /* + * The sender enters disordered state when it has received DUPACKs or + * SACKs in the last round of packets sent. This could be due to packet + * loss or reordering but needs further information to confirm packets + * have been lost. + */ TCP_CA_Disorder = 1, #define TCPF_CA_Disorder (1<<TCP_CA_Disorder) + /* + * The sender enters Congestion Window Reduction (CWR) state when it + * has received ACKs with ECN-ECE marks, or has experienced congestion + * or packet discard on the sender host (e.g. qdisc). + */ TCP_CA_CWR = 2, #define TCPF_CA_CWR (1<<TCP_CA_CWR) + /* + * The sender is in fast recovery and retransmitting lost packets, + * typically triggered by ACK events. + */ TCP_CA_Recovery = 3, #define TCPF_CA_Recovery (1<<TCP_CA_Recovery) + /* + * The sender is in loss recovery triggered by retransmission timeout. + */ TCP_CA_Loss = 4 #define TCPF_CA_Loss (1<<TCP_CA_Loss) }; |