diff options
| author |  Mubashir Adnan Qureshi <mubashirq@google.com>
| 2022-10-26 13:51:12 +0000 |
|---|---|---|
| committer |  David S. Miller <davem@davemloft.net>
| 2022-10-28 10:47:42 +0100 |
| commit | 1a91bb7c3ebf95e908ec33220defbcda1ecc072f (patch) | |
| tree | 16dcf09023e80efd8e75368ca4a43ec417141532 /net/ipv4/tcp_ipv4.c | |
| parent | tcp: add sysctls for TCP PLB parameters (diff) | |
| download | linux-1a91bb7c3ebf95e908ec33220defbcda1ecc072f.tar.gz linux-1a91bb7c3ebf95e908ec33220defbcda1ecc072f.tar.bz2 linux-1a91bb7c3ebf95e908ec33220defbcda1ecc072f.zip | |
tcp: add PLB functionality for TCP
Congestion control algorithms track PLB state and cause the connection
to trigger a path change when either of the 2 conditions is satisfied:
- No packets are in flight and (# consecutive congested rounds >=
sysctl_tcp_plb_idle_rehash_rounds)
- (# consecutive congested rounds >= sysctl_tcp_plb_rehash_rounds)
A round (RTT) is marked as congested when congestion signal
(ECN ce_ratio) over an RTT is greater than sysctl_tcp_plb_cong_thresh.
In the event of RTO, PLB (via tcp_write_timeout()) triggers a path
change and disables congestion-triggered path changes for random time
between (sysctl_tcp_plb_suspend_rto_sec, 2*sysctl_tcp_plb_suspend_rto_sec)
to avoid hopping onto the "connectivity blackhole". RTO-triggered
path changes can still happen during this cool-off period.
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>
Diffstat (limited to 'net/ipv4/tcp_ipv4.c')
| -rw-r--r-- | net/ipv4/tcp_ipv4.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 58b838b56c7f..ebab9e8b184c 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -3224,7 +3224,7 @@ static int __net_init tcp_sk_init(struct net *net) net->ipv4.sysctl_tcp_plb_rehash_rounds = 12; net->ipv4.sysctl_tcp_plb_suspend_rto_sec = 60; /* Default congestion threshold for PLB to mark a round is 50% */ - net->ipv4.sysctl_tcp_plb_cong_thresh = 128; + net->ipv4.sysctl_tcp_plb_cong_thresh = (1 << TCP_PLB_SCALE) / 2; /* Reno is always built in */ if (!net_eq(net, &init_net) && |