kernel.git/net/ipv6/udplite.c, branch linux-2.6.36.y

net: spread __net_init, __net_exit

2010-01-18T03:16:02Z

__net_init/__net_exit are apparently not going away, so use them to full extent. In some cases __net_init was removed, because it was called from __net_exit code. Signed-off-by: Alexey Dobriyan Signed-off-by: David S. Miller

net: drop capability from protocol definitions

2009-11-06T05:40:17Z

struct can_proto had a capability field which wasn't ever used. It is dropped entirely. struct inet_protosw had a capability field which can be more clearly expressed in the code by just checking if sock->type = SOCK_RAW. Signed-off-by: Eric Paris Acked-by: Arnaldo Carvalho de Melo Signed-off-by: David S. Miller

net: constify struct inet6_protocol

2009-09-15T00:03:05Z

Signed-off-by: Alexey Dobriyan Signed-off-by: David S. Miller

ipv6: Use correct data types for ICMPv6 type and code

2009-06-23T11:31:07Z

Change all the code that deals directly with ICMPv6 type and code values to use u8 instead of a signed int as that's the actual data type. Signed-off-by: Brian Haley Signed-off-by: David S. Miller

udp: RCU handling for Unicast packets.

2008-10-29T09:11:14Z

Goals are : 1) Optimizing handling of incoming Unicast UDP frames, so that no memory writes should happen in the fast path. Note: Multicasts and broadcasts still will need to take a lock, because doing a full lockless lookup in this case is difficult. 2) No expensive operations in the socket bind/unhash phases : - No expensive synchronize_rcu() calls. - No added rcu_head in socket structure, increasing memory needs, but more important, forcing us to use call_rcu() calls, that have the bad property of making sockets structure cold. (rcu grace period between socket freeing and its potential reuse make this socket being cold in CPU cache). David did a previous patch using call_rcu() and noticed a 20% impact on TCP connection rates. Quoting Cristopher Lameter : "Right. That results in cacheline cooldown. You'd want to recycle the object as they are cache hot on a per cpu basis. That is screwed up by the delayed regular rcu processing. We have seen multiple regressions due to cacheline cooldown. The only choice in cacheline hot sensitive areas is to deal with the complexity that comes with SLAB_DESTROY_BY_RCU or give up on RCU." - Because udp sockets are allocated from dedicated kmem_cache, use of SLAB_DESTROY_BY_RCU can help here. Theory of operation : --------------------- As the lookup is lockfree (using rcu_read_lock()/rcu_read_unlock()), special attention must be taken by readers and writers. Use of SLAB_DESTROY_BY_RCU is tricky too, because a socket can be freed, reused, inserted in a different chain or in worst case in the same chain while readers could do lookups in the same time. In order to avoid loops, a reader must check each socket found in a chain really belongs to the chain the reader was traversing. If it finds a mismatch, lookup must start again at the begining. This *restart* loop is the reason we had to use rdlock for the multicast case, because we dont want to send same message several times to the same socket. We use RCU only for fast path. Thus, /proc/net/udp still takes spinlocks. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

udp: introduce struct udp_table and multiple spinlocks

2008-10-29T08:41:45Z

UDP sockets are hashed in a 128 slots hash table. This hash table is protected by *one* rwlock. This rwlock is readlocked each time an incoming UDP message is handled. This rwlock is writelocked each time a socket must be inserted in hash table (bind time), or deleted from this table (close time) This is not scalable on SMP machines : 1) Even in read mode, lock() and unlock() are atomic operations and must dirty a contended cache line, shared by all cpus. 2) A writer might be starved if many readers are 'in flight'. This can happen on a machine with some NIC receiving many UDP messages. User process can be delayed a long time at socket creation/dismantle time. This patch prepares RCU migration, by introducing 'struct udp_table and struct udp_hslot', and using one spinlock per chain, to reduce contention on central rwlock. Introducing one spinlock per chain reduces latencies, for port randomization on heavily loaded UDP servers. This also speedup bindings to specific ports. udp_lib_unhash() was uninlined, becoming to big. Some cleanups were done to ease review of following patch (RCUification of UDP Unicast lookups) Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

netns: make uplitev6 mib per/namespace

2008-10-07T21:50:06Z

Signed-off-by: Denis V. Lunev Signed-off-by: David S. Miller

net: remove CVS keywords

2008-06-12T04:00:38Z

This patch removes CVS keywords that weren't updated for a long time from comments. Signed-off-by: Adrian Bunk Signed-off-by: David S. Miller

[UDP]: Remove owner from udp_seq_afinfo.

2008-03-29T01:25:53Z

Move it to udp_seq_afinfo->seq_fops as should be. Signed-off-by: Denis V. Lunev Signed-off-by: David S. Miller

[UDP]: Place file operations directly into udp_seq_afinfo.

2008-03-29T01:25:32Z

No need to have separate never-used variable. Signed-off-by: Denis V. Lunev Signed-off-by: David S. Miller