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[NET] Generalise TCP's struct open_request minisock infrastructure

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Kept this first changeset minimal, without changing existing names to
ease peer review.

Basicaly tcp_openreq_alloc now receives the or_calltable, that in turn
has two new members:

->slab, that replaces tcp_openreq_cachep
->obj_size, to inform the size of the openreq descendant for
  a specific protocol

The protocol specific fields in struct open_request were moved to a
class hierarchy, with the things that are common to all connection
oriented PF_INET protocols in struct inet_request_sock, the TCP ones
in tcp_request_sock, that is an inet_request_sock, that is an
open_request.

I.e. this uses the same approach used for the struct sock class
hierarchy, with sk_prot indicating if the protocol wants to use the
open_request infrastructure by filling in sk_prot->rsk_prot with an
or_calltable.

Results? Performance is improved and TCP v4 now uses only 64 bytes per
open request minisock, down from 96 without this patch :-)

Next changeset will rename some of the structs, fields and functions
mentioned above, struct or_calltable is way unclear, better name it
struct request_sock_ops, s/struct open_request/struct request_sock/g,
etc.

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
2005-06-18 22:46:52 -07:00
committed by David S. Miller
parent 1944972d3b
commit 2e6599cb89
16 changed files with 341 additions and 230 deletions
Download Patch File Download Diff File Expand all files Collapse all files

87
include/net/tcp.h
View File

@ -31,6 +31,7 @@
#include <linux/cache.h>
#include <linux/percpu.h>
#include <net/checksum.h>
#include <net/request_sock.h>
#include <net/sock.h>
#include <net/snmp.h>
#include <net/ip.h>
@ -613,74 +614,6 @@ extern atomic_t tcp_memory_allocated;
extern atomic_t tcp_sockets_allocated;
extern int tcp_memory_pressure;
struct open_request;
struct or_calltable {
int family;
int (*rtx_syn_ack) (struct sock *sk, struct open_request *req, struct dst_entry*);
void (*send_ack) (struct sk_buff *skb, struct open_request *req);
void (*destructor) (struct open_request *req);
void (*send_reset) (struct sk_buff *skb);
};
struct tcp_v4_open_req {
__u32 loc_addr;
__u32 rmt_addr;
struct ip_options *opt;
};
#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
struct tcp_v6_open_req {
struct in6_addr loc_addr;
struct in6_addr rmt_addr;
struct sk_buff *pktopts;
int iif;
};
#endif
/* this structure is too big */
struct open_request {
struct open_request *dl_next; /* Must be first member! */
__u32 rcv_isn;
__u32 snt_isn;
__u16 rmt_port;
__u16 mss;
__u8 retrans;
__u8 __pad;
__u16 snd_wscale : 4,
rcv_wscale : 4,
tstamp_ok : 1,
sack_ok : 1,
wscale_ok : 1,
ecn_ok : 1,
acked : 1;
/* The following two fields can be easily recomputed I think -AK */
__u32 window_clamp; /* window clamp at creation time */
__u32 rcv_wnd; /* rcv_wnd offered first time */
__u32 ts_recent;
unsigned long expires;
struct or_calltable *class;
struct sock *sk;
union {
struct tcp_v4_open_req v4_req;
#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
struct tcp_v6_open_req v6_req;
#endif
} af;
};
/* SLAB cache for open requests. */
extern kmem_cache_t *tcp_openreq_cachep;
#define tcp_openreq_alloc() kmem_cache_alloc(tcp_openreq_cachep, SLAB_ATOMIC)
#define tcp_openreq_fastfree(req) kmem_cache_free(tcp_openreq_cachep, req)
static inline void tcp_openreq_free(struct open_request *req)
{
req->class->destructor(req);
tcp_openreq_fastfree(req);
}
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
#define TCP_INET_FAMILY(fam) ((fam) == AF_INET)
#else
@ -1832,17 +1765,19 @@ static __inline__ void tcp_openreq_init(struct open_request *req,
struct tcp_options_received *rx_opt,
struct sk_buff *skb)
{
struct inet_request_sock *ireq = inet_rsk(req);
req->rcv_wnd = 0; /* So that tcp_send_synack() knows! */
req->rcv_isn = TCP_SKB_CB(skb)->seq;
tcp_rsk(req)->rcv_isn = TCP_SKB_CB(skb)->seq;
req->mss = rx_opt->mss_clamp;
req->ts_recent = rx_opt->saw_tstamp ? rx_opt->rcv_tsval : 0;
req->tstamp_ok = rx_opt->tstamp_ok;
req->sack_ok = rx_opt->sack_ok;
req->snd_wscale = rx_opt->snd_wscale;
req->wscale_ok = rx_opt->wscale_ok;
req->acked = 0;
req->ecn_ok = 0;
req->rmt_port = skb->h.th->source;
ireq->tstamp_ok = rx_opt->tstamp_ok;
ireq->sack_ok = rx_opt->sack_ok;
ireq->snd_wscale = rx_opt->snd_wscale;
ireq->wscale_ok = rx_opt->wscale_ok;
ireq->acked = 0;
ireq->ecn_ok = 0;
ireq->rmt_port = skb->h.th->source;
}
extern void tcp_enter_memory_pressure(void);