[INET]: Generalise tcp_tw_bucket, aka TIME_WAIT sockets

This paves the way to generalise the rest of the sock ID lookup
routines and saves some bytes in TCPv4 TIME_WAIT sockets on distro
kernels (where IPv6 is always built as a module):

[root@qemu ~]# grep tw_sock /proc/slabinfo
tw_sock_TCPv6  0  0  128  31  1
tw_sock_TCP    0  0   96  41  1
[root@qemu ~]#

Now if a protocol wants to use the TIME_WAIT generic infrastructure it
only has to set the sk_prot->twsk_obj_size field with the size of its
inet_timewait_sock derived sock and proto_register will create
sk_prot->twsk_slab, for now its only for INET sockets, but we can
introduce timewait_sock later if some non INET transport protocolo
wants to use this stuff.

Next changesets will take advantage of this new infrastructure to
generalise even more TCP code.

[acme@toy net-2.6.14]$ grep built-in /tmp/before.size /tmp/after.size
/tmp/before.size: 188646   11764    5068  205478   322a6 net/ipv4/built-in.o
/tmp/after.size:  188144   11764    5068  204976   320b0 net/ipv4/built-in.o
[acme@toy net-2.6.14]$

Tested with both IPv4 & IPv6 (::1 (localhost) & ::ffff:172.20.0.1
(qemu host)).

Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Arnaldo Carvalho de Melo
2005-08-09 20:09:30 -07:00
committed by David S. Miller
parent 33b6223190
commit 8feaf0c0a5
13 changed files with 484 additions and 391 deletions

View File

@@ -88,6 +88,7 @@ do { spin_lock_init(&((__sk)->sk_lock.slock)); \
} while(0)
struct sock;
struct proto;
/**
* struct sock_common - minimal network layer representation of sockets
@@ -98,10 +99,11 @@ struct sock;
* @skc_node: main hash linkage for various protocol lookup tables
* @skc_bind_node: bind hash linkage for various protocol lookup tables
* @skc_refcnt: reference count
* @skc_prot: protocol handlers inside a network family
*
* This is the minimal network layer representation of sockets, the header
* for struct sock and struct tcp_tw_bucket.
*/
* for struct sock and struct inet_timewait_sock.
*/
struct sock_common {
unsigned short skc_family;
volatile unsigned char skc_state;
@@ -110,11 +112,12 @@ struct sock_common {
struct hlist_node skc_node;
struct hlist_node skc_bind_node;
atomic_t skc_refcnt;
struct proto *skc_prot;
};
/**
* struct sock - network layer representation of sockets
* @__sk_common: shared layout with tcp_tw_bucket
* @__sk_common: shared layout with inet_timewait_sock
* @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
* @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
* @sk_lock: synchronizer
@@ -140,7 +143,6 @@ struct sock_common {
* @sk_backlog: always used with the per-socket spinlock held
* @sk_callback_lock: used with the callbacks in the end of this struct
* @sk_error_queue: rarely used
* @sk_prot: protocol handlers inside a network family
* @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt, IPV6_ADDRFORM for instance)
* @sk_err: last error
* @sk_err_soft: errors that don't cause failure but are the cause of a persistent failure not just 'timed out'
@@ -173,7 +175,7 @@ struct sock_common {
*/
struct sock {
/*
* Now struct tcp_tw_bucket also uses sock_common, so please just
* Now struct inet_timewait_sock also uses sock_common, so please just
* don't add nothing before this first member (__sk_common) --acme
*/
struct sock_common __sk_common;
@@ -184,6 +186,7 @@ struct sock {
#define sk_node __sk_common.skc_node
#define sk_bind_node __sk_common.skc_bind_node
#define sk_refcnt __sk_common.skc_refcnt
#define sk_prot __sk_common.skc_prot
unsigned char sk_shutdown : 2,
sk_no_check : 2,
sk_userlocks : 4;
@@ -218,7 +221,6 @@ struct sock {
struct sk_buff *tail;
} sk_backlog;
struct sk_buff_head sk_error_queue;
struct proto *sk_prot;
struct proto *sk_prot_creator;
rwlock_t sk_callback_lock;
int sk_err,
@@ -557,6 +559,9 @@ struct proto {
kmem_cache_t *slab;
unsigned int obj_size;
kmem_cache_t *twsk_slab;
unsigned int twsk_obj_size;
struct request_sock_ops *rsk_prot;
struct module *owner;