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| author | David S. Miller <davem@davemloft.net> | 2018-05-17 22:41:30 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-05-17 22:41:30 +0300 |
| commit | 10e361e1006eec2b4b369481ee1509c58004bda8 (patch) | |
| tree | c543d69724d87f1128c00ce80843727902515fdf /include | |
| parent | 9611d6d6e24cd40ff887bdbb4dfe36a2ee88d488 (diff) | |
| parent | 56f8c5d78f5746f48abf6d1f0bc2945dc59277ee (diff) | |
| download | linux-10e361e1006eec2b4b369481ee1509c58004bda8.tar.xz | |
Merge branch 'tcp-default-RACK-loss-recovery'
Yuchung Cheng says:
====================
tcp: default RACK loss recovery
This patch set implements the features correspond to the
draft-ietf-tcpm-rack-03 version of the RACK draft.
https://datatracker.ietf.org/meeting/101/materials/slides-101-tcpm-update-on-tcp-rack-00
1. SACK: implement equivalent DUPACK threshold heuristic in RACK to
replace existing RFC6675 recovery (tcp_mark_head_lost).
2. Non-SACK: simplify RFC6582 NewReno implementation
3. RTO: apply RACK's time-based approach to avoid spuriouly
marking very recently sent packets lost.
4. with (1)(2)(3), make RACK the exclusive fast recovery mechanism to
mark losses based on time on S/ACK. Tail loss probe and F-RTO remain
enabled by default as complementary mechanisms to send probes in
CA_Open and CA_Loss states. The probes would solicit S/ACKs to trigger
RACK time-based loss detection.
All Google web and internal servers have been running RACK-only mode
(4) for a while now. a/b experiments indicate RACK/TLP on average
reduces recovery latency by 10% compared to RFC6675. RFC6675
is default-off now but can be enabled by disabling RACK (sysctl
net.ipv4.tcp_recovery=0) for unseen issues.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/tcp.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h index a08eab58ef70..6deb540297cc 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -245,6 +245,7 @@ extern long sysctl_tcp_mem[3]; #define TCP_RACK_LOSS_DETECTION 0x1 /* Use RACK to detect losses */ #define TCP_RACK_STATIC_REO_WND 0x2 /* Use static RACK reo wnd */ +#define TCP_RACK_NO_DUPTHRESH 0x4 /* Do not use DUPACK threshold in RACK */ extern atomic_long_t tcp_memory_allocated; extern struct percpu_counter tcp_sockets_allocated; @@ -1876,6 +1877,10 @@ void tcp_v4_init(void); void tcp_init(void); /* tcp_recovery.c */ +void tcp_mark_skb_lost(struct sock *sk, struct sk_buff *skb); +void tcp_newreno_mark_lost(struct sock *sk, bool snd_una_advanced); +extern s32 tcp_rack_skb_timeout(struct tcp_sock *tp, struct sk_buff *skb, + u32 reo_wnd); extern void tcp_rack_mark_lost(struct sock *sk); extern void tcp_rack_advance(struct tcp_sock *tp, u8 sacked, u32 end_seq, u64 xmit_time); |