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| author | JP Abgrall <jpa@google.com> | 2014-02-19 15:07:00 -0800 |
|---|---|---|
| committer | Ziyan <jaraidaniel@gmail.com> | 2016-03-11 15:57:16 +0100 |
| commit | 8b7eb8c06c6b27151d3b150e72bc426cc941a9af (patch) | |
| tree | 77412560edbc8c4e4192b271d592678b87915f03 /net/ipv4/sysctl_net_ipv4.c | |
| parent | cdf109d29ca5f3ae92f0d2e5075c466e5ef2c32b (diff) | |
| download | kernel_samsung_espresso10-8b7eb8c06c6b27151d3b150e72bc426cc941a9af.tar.gz kernel_samsung_espresso10-8b7eb8c06c6b27151d3b150e72bc426cc941a9af.tar.bz2 kernel_samsung_espresso10-8b7eb8c06c6b27151d3b150e72bc426cc941a9af.zip | |
tcp: add a sysctl to config the tcp_default_init_rwnd
The default initial rwnd was 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: I7eac8a0a5133371aea9ecb9aec0b608bd7f2cc57
Signed-off-by: JP Abgrall <jpa@google.com>
Diffstat (limited to 'net/ipv4/sysctl_net_ipv4.c')
| -rw-r--r-- | net/ipv4/sysctl_net_ipv4.c | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c index 3a22b1c4c08..3c749129135 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -121,6 +121,21 @@ static int ipv4_ping_group_range(ctl_table *table, int write, return ret; } +/* Validate changes from /proc interface. */ +static int proc_tcp_default_init_rwnd(ctl_table *ctl, int write, + void __user *buffer, + size_t *lenp, loff_t *ppos) +{ + int old_value = *(int *)ctl->data; + int ret = proc_dointvec(ctl, write, buffer, lenp, ppos); + int new_value = *(int *)ctl->data; + + if (write && ret == 0 && (new_value < 3 || new_value > 100)) + *(int *)ctl->data = old_value; + + return ret; +} + static int proc_tcp_congestion_control(ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { @@ -656,7 +671,7 @@ static struct ctl_table ipv4_table[] = { .mode = 0644, .proc_handler = proc_dointvec }, - { + { .procname = "tcp_thin_dupack", .data = &sysctl_tcp_thin_dupack, .maxlen = sizeof(int), @@ -664,6 +679,13 @@ static struct ctl_table ipv4_table[] = { .proc_handler = proc_dointvec }, { + .procname = "tcp_default_init_rwnd", + .data = &sysctl_tcp_default_init_rwnd, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_tcp_default_init_rwnd + }, + { .procname = "udp_mem", .data = &sysctl_udp_mem, .maxlen = sizeof(sysctl_udp_mem), |