[PATCH] net: compute a more reasonable default ip6_rt_max_size
From: Arun Sharma <hidden>
Date: 2012-05-25 20:16:49
Also in:
lkml
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
The algorithm is based on ipv4 and alloc_large_system_hash().
The following data is from a x86_64 box I tested:
128MB
$ cat /proc/sys/net/ipv{4,6}/route/max_size
16384
22444
512MB
$ cat /proc/sys/net/ipv{4,6}/route/max_size
65536
99856
1GB
$ cat /proc/sys/net/ipv{4,6}/route/max_size
524288
203068
2GB
$ cat /proc/sys/net/ipv{4,6}/route/max_size
1048576
524288
4GB
$ cat /proc/sys/net/ipv{4,6}/route/max_size
2097152
524288
Signed-off-by: Arun Sharma <redacted>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: David Miller <davem@davemloft.net>
---
net/ipv6/route.c | 21 ++++++++++++++++++++-
1 files changed, 20 insertions(+), 1 deletions(-)
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 49d6ce1..c89ebbb 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c@@ -2827,6 +2827,16 @@ struct ctl_table * __net_init ipv6_route_sysctl_init(struct net *net) } #endif +static __initdata unsigned long ip6_rt_entries; +static int __init set_rt_entries(char *str) +{ + if (!str) + return 0; + ip6_rt_entries = simple_strtoul(str, &str, 0); + return 1; +} +__setup("ip6_rt_entries=", set_rt_entries); + static int __net_init ip6_route_net_init(struct net *net) { int ret = -ENOMEM;
@@ -2872,8 +2882,17 @@ static int __net_init ip6_route_net_init(struct net *net) ip6_template_metrics, true); #endif + /* Compute a reasonable default based on what we do for ipv4 + * total size = 1/16th of total RAM + * No more than 512k entries unless overridden on kernel cmdline */ + if (ip6_rt_entries == 0) { + ip6_rt_entries = (totalram_pages << PAGE_SHIFT) >> 4; + ip6_rt_entries /= sizeof(struct rt6_info); + ip6_rt_entries = min(512 * 1024UL, ip6_rt_entries); + } + net->ipv6.sysctl.flush_delay = 0; - net->ipv6.sysctl.ip6_rt_max_size = 4096; + net->ipv6.sysctl.ip6_rt_max_size = ip6_rt_entries; net->ipv6.sysctl.ip6_rt_gc_min_interval = HZ / 2; net->ipv6.sysctl.ip6_rt_gc_timeout = 60*HZ; net->ipv6.sysctl.ip6_rt_gc_interval = 30*HZ;
--
1.7.8.4