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inet: Decrease overhead of on-stack inet_cork.
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When we fast path datagram sends to avoid locking by putting
the inet_cork on the stack we use up lots of space that isn't
necessary.

This is because inet_cork contains a "struct flowi" which isn't
used in these code paths.

Split inet_cork to two parts, "inet_cork" and "inet_cork_full".
Only the latter of which has the "struct flowi" and is what is
stored in inet_sock.

Signed-off-by: David S. Miller <[email protected]>
Acked-by: Eric Dumazet <[email protected]>
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@davem330
davem330 committed May 6, 2011
1 parent ad638bd commit bdc712b
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Showing 5 changed files with 41 additions and 33 deletions.
12 changes: 8 additions & 4 deletions include/net/inet_sock.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -96,17 +96,21 @@ static inline struct inet_request_sock *inet_rsk(const struct request_sock *sk)

struct inet_cork {
unsigned int flags;
unsigned int fragsize;
__be32 addr;
struct ip_options *opt;
unsigned int fragsize;
struct dst_entry *dst;
int length; /* Total length of all frames */
__be32 addr;
struct flowi fl;
struct page *page;
u32 off;
u8 tx_flags;
};

struct inet_cork_full {
struct inet_cork base;
struct flowi fl;
};

struct ip_mc_socklist;
struct ipv6_pinfo;
struct rtable;
Expand Down Expand Up @@ -164,7 +168,7 @@ struct inet_sock {
int mc_index;
__be32 mc_addr;
struct ip_mc_socklist __rcu *mc_list;
struct inet_cork cork;
struct inet_cork_full cork;
};

#define IPCORK_OPT 1 /* ip-options has been held in ipcork.opt */
Expand Down
2 changes: 1 addition & 1 deletion include/net/ip.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -132,7 +132,7 @@ extern struct sk_buff *ip_make_skb(struct sock *sk,

static inline struct sk_buff *ip_finish_skb(struct sock *sk)
{
return __ip_make_skb(sk, &sk->sk_write_queue, &inet_sk(sk)->cork);
return __ip_make_skb(sk, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
}

/* datagram.c */
Expand Down
22 changes: 12 additions & 10 deletions net/ipv4/ip_output.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1096,14 +1096,14 @@ int ip_append_data(struct sock *sk,
return 0;

if (skb_queue_empty(&sk->sk_write_queue)) {
err = ip_setup_cork(sk, &inet->cork, ipc, rtp);
err = ip_setup_cork(sk, &inet->cork.base, ipc, rtp);
if (err)
return err;
} else {
transhdrlen = 0;
}

return __ip_append_data(sk, &sk->sk_write_queue, &inet->cork, getfrag,
return __ip_append_data(sk, &sk->sk_write_queue, &inet->cork.base, getfrag,
from, length, transhdrlen, flags);
}

Expand All @@ -1114,6 +1114,7 @@ ssize_t ip_append_page(struct sock *sk, struct page *page,
struct sk_buff *skb;
struct rtable *rt;
struct ip_options *opt = NULL;
struct inet_cork *cork;
int hh_len;
int mtu;
int len;
Expand All @@ -1129,28 +1130,29 @@ ssize_t ip_append_page(struct sock *sk, struct page *page,
if (skb_queue_empty(&sk->sk_write_queue))
return -EINVAL;

rt = (struct rtable *)inet->cork.dst;
if (inet->cork.flags & IPCORK_OPT)
opt = inet->cork.opt;
cork = &inet->cork.base;
rt = (struct rtable *)cork->dst;
if (cork->flags & IPCORK_OPT)
opt = cork->opt;

if (!(rt->dst.dev->features&NETIF_F_SG))
return -EOPNOTSUPP;

hh_len = LL_RESERVED_SPACE(rt->dst.dev);
mtu = inet->cork.fragsize;
mtu = cork->fragsize;

fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0);
maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen;

if (inet->cork.length + size > 0xFFFF - fragheaderlen) {
if (cork->length + size > 0xFFFF - fragheaderlen) {
ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->inet_dport, mtu);
return -EMSGSIZE;
}

if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
return -EINVAL;

inet->cork.length += size;
cork->length += size;
if ((size + skb->len > mtu) &&
(sk->sk_protocol == IPPROTO_UDP) &&
(rt->dst.dev->features & NETIF_F_UFO)) {
Expand Down Expand Up @@ -1245,7 +1247,7 @@ ssize_t ip_append_page(struct sock *sk, struct page *page,
return 0;

error:
inet->cork.length -= size;
cork->length -= size;
IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS);
return err;
}
Expand Down Expand Up @@ -1396,7 +1398,7 @@ static void __ip_flush_pending_frames(struct sock *sk,

void ip_flush_pending_frames(struct sock *sk)
{
__ip_flush_pending_frames(sk, &sk->sk_write_queue, &inet_sk(sk)->cork);
__ip_flush_pending_frames(sk, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
}

struct sk_buff *ip_make_skb(struct sock *sk,
Expand Down
34 changes: 18 additions & 16 deletions net/ipv6/ip6_output.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1150,6 +1150,7 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
{
struct inet_sock *inet = inet_sk(sk);
struct ipv6_pinfo *np = inet6_sk(sk);
struct inet_cork *cork;
struct sk_buff *skb;
unsigned int maxfraglen, fragheaderlen;
int exthdrlen;
Expand All @@ -1163,6 +1164,7 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,

if (flags&MSG_PROBE)
return 0;
cork = &inet->cork.base;
if (skb_queue_empty(&sk->sk_write_queue)) {
/*
* setup for corking
Expand Down Expand Up @@ -1202,7 +1204,7 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
/* need source address above miyazawa*/
}
dst_hold(&rt->dst);
inet->cork.dst = &rt->dst;
cork->dst = &rt->dst;
inet->cork.fl.u.ip6 = *fl6;
np->cork.hop_limit = hlimit;
np->cork.tclass = tclass;
Expand All @@ -1212,23 +1214,23 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
if (np->frag_size)
mtu = np->frag_size;
}
inet->cork.fragsize = mtu;
cork->fragsize = mtu;
if (dst_allfrag(rt->dst.path))
inet->cork.flags |= IPCORK_ALLFRAG;
inet->cork.length = 0;
cork->flags |= IPCORK_ALLFRAG;
cork->length = 0;
sk->sk_sndmsg_page = NULL;
sk->sk_sndmsg_off = 0;
exthdrlen = rt->dst.header_len + (opt ? opt->opt_flen : 0) -
rt->rt6i_nfheader_len;
length += exthdrlen;
transhdrlen += exthdrlen;
} else {
rt = (struct rt6_info *)inet->cork.dst;
rt = (struct rt6_info *)cork->dst;
fl6 = &inet->cork.fl.u.ip6;
opt = np->cork.opt;
transhdrlen = 0;
exthdrlen = 0;
mtu = inet->cork.fragsize;
mtu = cork->fragsize;
}

hh_len = LL_RESERVED_SPACE(rt->dst.dev);
Expand All @@ -1238,7 +1240,7 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr);

if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) {
if (inet->cork.length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) {
if (cork->length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) {
ipv6_local_error(sk, EMSGSIZE, fl6, mtu-exthdrlen);
return -EMSGSIZE;
}
Expand Down Expand Up @@ -1267,7 +1269,7 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
* --yoshfuji
*/

inet->cork.length += length;
cork->length += length;
if (length > mtu) {
int proto = sk->sk_protocol;
if (dontfrag && (proto == IPPROTO_UDP || proto == IPPROTO_RAW)){
Expand All @@ -1292,7 +1294,7 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,

while (length > 0) {
/* Check if the remaining data fits into current packet. */
copy = (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
if (copy < length)
copy = maxfraglen - skb->len;

Expand All @@ -1317,7 +1319,7 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
* we know we need more fragment(s).
*/
datalen = length + fraggap;
if (datalen > (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
datalen = maxfraglen - fragheaderlen;

fraglen = datalen + fragheaderlen;
Expand Down Expand Up @@ -1481,7 +1483,7 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
}
return 0;
error:
inet->cork.length -= length;
cork->length -= length;
IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
return err;
}
Expand All @@ -1497,10 +1499,10 @@ static void ip6_cork_release(struct inet_sock *inet, struct ipv6_pinfo *np)
np->cork.opt = NULL;
}

if (inet->cork.dst) {
dst_release(inet->cork.dst);
inet->cork.dst = NULL;
inet->cork.flags &= ~IPCORK_ALLFRAG;
if (inet->cork.base.dst) {
dst_release(inet->cork.base.dst);
inet->cork.base.dst = NULL;
inet->cork.base.flags &= ~IPCORK_ALLFRAG;
}
memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
}
Expand All @@ -1515,7 +1517,7 @@ int ip6_push_pending_frames(struct sock *sk)
struct net *net = sock_net(sk);
struct ipv6hdr *hdr;
struct ipv6_txoptions *opt = np->cork.opt;
struct rt6_info *rt = (struct rt6_info *)inet->cork.dst;
struct rt6_info *rt = (struct rt6_info *)inet->cork.base.dst;
struct flowi6 *fl6 = &inet->cork.fl.u.ip6;
unsigned char proto = fl6->flowi6_proto;
int err = 0;
Expand Down
4 changes: 2 additions & 2 deletions net/ipv6/raw.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -542,8 +542,8 @@ static int rawv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
goto out;

offset = rp->offset;
total_len = inet_sk(sk)->cork.length - (skb_network_header(skb) -
skb->data);
total_len = inet_sk(sk)->cork.base.length - (skb_network_header(skb) -
skb->data);
if (offset >= total_len - 1) {
err = -EINVAL;
ip6_flush_pending_frames(sk);
Expand Down

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