diff options
| author | Eric Dumazet <edumazet@google.com> | 2014-06-02 05:26:03 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-08-14 09:38:23 +0800 |
| commit | 265459c3d15b39826d09b3380eef7572fb7649a2 (patch) | |
| tree | 575b38e48d818bc386180fe7ce2fe7645cf317bc /net/ipv4/ipmr.c | |
| parent | 910c396e1c58e0f6f6c817edf9292f245779ec65 (diff) | |
inetpeer: get rid of ip_id_count
[ Upstream commit 73f156a6e8c1074ac6327e0abd1169e95eb66463 ]
Ideally, we would need to generate IP ID using a per destination IP
generator.
linux kernels used inet_peer cache for this purpose, but this had a huge
cost on servers disabling MTU discovery.
1) each inet_peer struct consumes 192 bytes
2) inetpeer cache uses a binary tree of inet_peer structs,
with a nominal size of ~66000 elements under load.
3) lookups in this tree are hitting a lot of cache lines, as tree depth
is about 20.
4) If server deals with many tcp flows, we have a high probability of
not finding the inet_peer, allocating a fresh one, inserting it in
the tree with same initial ip_id_count, (cf secure_ip_id())
5) We garbage collect inet_peer aggressively.
IP ID generation do not have to be 'perfect'
Goal is trying to avoid duplicates in a short period of time,
so that reassembly units have a chance to complete reassembly of
fragments belonging to one message before receiving other fragments
with a recycled ID.
We simply use an array of generators, and a Jenkin hash using the dst IP
as a key.
ipv6_select_ident() is put back into net/ipv6/ip6_output.c where it
belongs (it is only used from this file)
secure_ip_id() and secure_ipv6_id() no longer are needed.
Rename ip_select_ident_more() to ip_select_ident_segs() to avoid
unnecessary decrement/increment of the number of segments.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/ipv4/ipmr.c')
| -rw-r--r-- | net/ipv4/ipmr.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c index 28863570dd60..1149fc2290e2 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -1663,7 +1663,7 @@ static void ip_encap(struct sk_buff *skb, __be32 saddr, __be32 daddr) iph->protocol = IPPROTO_IPIP; iph->ihl = 5; iph->tot_len = htons(skb->len); - ip_select_ident(skb, skb_dst(skb), NULL); + ip_select_ident(skb, NULL); ip_send_check(iph); memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); |