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authorFlorian Westphal <fw@strlen.de>2014-09-26 22:37:34 +0200
committerDavid S. Miller <davem@davemloft.net>2014-09-29 00:13:10 -0400
commit7354c8c389d18719dd71cc810da70b0921d66694 (patch)
tree776fa6ce824557d0c8bbf4271ad3b08a4832a66f /include/net
parent30e502a34b8b21fae2c789da102bd9f6e99fef83 (diff)
net: tcp: split ack slow/fast events from cwnd_event
The congestion control ops "cwnd_event" currently supports CA_EVENT_FAST_ACK and CA_EVENT_SLOW_ACK events (among others). Both FAST and SLOW_ACK are only used by Westwood congestion control algorithm. This removes both flags from cwnd_event and adds a new in_ack_event callback for this. The goal is to be able to provide more detailed information about ACKs, such as whether ECE flag was set, or whether the ACK resulted in a window update. It is required for DataCenter TCP (DCTCP) congestion control algorithm as it makes a different choice depending on ECE being set or not. Joint work with Daniel Borkmann and Glenn Judd. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Glenn Judd <glenn.judd@morganstanley.com> Acked-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net')
-rw-r--r--include/net/tcp.h8
1 files changed, 6 insertions, 2 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h
index a12f145cfbc..7ec6a28305c 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -763,8 +763,10 @@ enum tcp_ca_event {
CA_EVENT_CWND_RESTART, /* congestion window restart */
CA_EVENT_COMPLETE_CWR, /* end of congestion recovery */
CA_EVENT_LOSS, /* loss timeout */
- CA_EVENT_FAST_ACK, /* in sequence ack */
- CA_EVENT_SLOW_ACK, /* other ack */
+};
+
+enum tcp_ca_ack_event_flags {
+ CA_ACK_SLOWPATH = (1 << 0),
};
/*
@@ -796,6 +798,8 @@ struct tcp_congestion_ops {
void (*set_state)(struct sock *sk, u8 new_state);
/* call when cwnd event occurs (optional) */
void (*cwnd_event)(struct sock *sk, enum tcp_ca_event ev);
+ /* call when ack arrives (optional) */
+ void (*in_ack_event)(struct sock *sk, u32 flags);
/* new value of cwnd after loss (optional) */
u32 (*undo_cwnd)(struct sock *sk);
/* hook for packet ack accounting (optional) */