diff options
| author | JP Abgrall <jpa@google.com> | 2014-02-07 18:40:10 -0800 |
|---|---|---|
| committer | JP Abgrall <jpa@google.com> | 2014-02-07 18:40:10 -0800 |
| commit | 969ff3bbb38b6622800a1a4bd38404e3701193de (patch) | |
| tree | aa4dadf867bea6de598b98ceceabc6d6e40d3e29 /net/ipv4/tcp_input.c | |
| parent | 43fcab022e7eef42e0bbcc7b955e8de2ef1469a4 (diff) | |
tcp: add a sysctl to config the tcp_default_init_rwnd
The default initial rwnd is hardcoded to 10.
Now we allow it to be controlled via
/proc/sys/net/ipv4/tcp_default_init_rwnd
which limits the values from 3 to 100
This is somewhat needed because ipv6 routes are
autoconfigured by the kernel.
See "An Argument for Increasing TCP's Initial Congestion Window"
in https://developers.google.com/speed/articles/tcp_initcwnd_paper.pdf
Change-Id: I386b2a9d62de0ebe05c1ebe1b4bd91b314af5c54
Signed-off-by: JP Abgrall <jpa@google.com>
Conflicts:
net/ipv4/sysctl_net_ipv4.c
net/ipv4/tcp_input.c
Diffstat (limited to 'net/ipv4/tcp_input.c')
| -rw-r--r-- | net/ipv4/tcp_input.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 9c6225780bd5..4189682d9ade 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -98,6 +98,7 @@ int sysctl_tcp_thin_dupack __read_mostly; int sysctl_tcp_moderate_rcvbuf __read_mostly = 1; int sysctl_tcp_early_retrans __read_mostly = 3; +int sysctl_tcp_default_init_rwnd __read_mostly = TCP_DEFAULT_INIT_RCVWND; #define FLAG_DATA 0x01 /* Incoming frame contained data. */ #define FLAG_WIN_UPDATE 0x02 /* Incoming ACK was a window update. */ @@ -351,14 +352,14 @@ static void tcp_grow_window(struct sock *sk, const struct sk_buff *skb) static void tcp_fixup_rcvbuf(struct sock *sk) { u32 mss = tcp_sk(sk)->advmss; - u32 icwnd = TCP_DEFAULT_INIT_RCVWND; + u32 icwnd = sysctl_tcp_default_init_rwnd; int rcvmem; /* Limit to 10 segments if mss <= 1460, * or 14600/mss segments, with a minimum of two segments. */ if (mss > 1460) - icwnd = max_t(u32, (1460 * TCP_DEFAULT_INIT_RCVWND) / mss, 2); + icwnd = max_t(u32, (1460 * icwnd) / mss, 2); rcvmem = SKB_TRUESIZE(mss + MAX_TCP_HEADER); while (tcp_win_from_space(rcvmem) < mss) |