diff options
| author | Arnaldo Carvalho de Melo <acme@mandriva.com> | 2006-11-27 17:58:02 -0200 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2006-12-02 21:30:47 -0800 |
| commit | d5c42c0ec4f7fd5a4e19e33a2d561758b67c55c8 (patch) | |
| tree | e5967dea50bc2b4c06a4d936d9b4b776d31ff24e | |
| parent | 850db6b8c53ff12eadee9ef2aa69360c06bce057 (diff) | |
[NET]: Pack struct hh_cache
[acme@newtoy net-2.6.20]$ pahole net/ipv4/tcp.o hh_cache
/* /pub/scm/linux/kernel/git/acme/net-2.6.20/include/linux/netdevice.h:190 */
struct hh_cache {
struct hh_cache * hh_next; /* 0 4 */
atomic_t hh_refcnt; /* 4 4 */
__be16 hh_type; /* 8 2 */
/* XXX 2 bytes hole, try to pack */
int hh_len; /* 12 4 */
int (*hh_output)(); /* 16 4 */
rwlock_t hh_lock; /* 20 36 */
long unsigned int hh_data[24]; /* 56 96 */
}; /* size: 152, sum members: 150, holes: 1, sum holes: 2 */
[acme@newtoy net-2.6.20]$ find net -name "*.[ch]" | xargs grep 'hh_len.\+=' | sort -u
net/atm/br2684.c: hh->hh_len = PADLEN + ETH_HLEN;
net/ethernet/eth.c: hh->hh_len = ETH_HLEN;
net/ipv4/ipconfig.c: int hh_len = LL_RESERVED_SPACE(dev);
net/ipv4/ip_output.c: hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
net/ipv4/ip_output.c: int hh_len = LL_RESERVED_SPACE(dev);
net/ipv4/netfilter.c: hh_len = (*pskb)->dst->dev->hard_header_len;
net/ipv4/raw.c: hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
net/ipv6/ip6_output.c: hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
net/ipv6/netfilter/ip6t_REJECT.c: hh_len = (dst->dev->hard_header_len + 15)&~15;
net/ipv6/raw.c: hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
[acme@newtoy net-2.6.20]$
[acme@newtoy net-2.6.20]$ find include -name "*.h" | xargs grep 'define ETH_HLEN'
include/linux/if_ether.h:#define ETH_HLEN 14 /* Total octets in header. */
(((dev)->hard_header_len&~(HH_DATA_MOD - 1)) + HH_DATA_MOD)
[acme@newtoy net-2.6.20]$ pahole net/ipv4/tcp.o net_device | grep hard_header_len
short unsigned int hard_header_len; /* 106 2 */
[acme@newtoy net-2.6.20]$
So I think we're safe in turning hh_len an u16, end result:
[acme@newtoy net-2.6.20]$ codiff -sV /tmp/tcp.o.before net/ipv4/tcp.o
/pub/scm/linux/kernel/git/acme/net-2.6.20/net/ipv4/tcp.c:
struct hh_cache | -4
hh_len;
from: int /* 12(0) 4(0) */
to: u16 /* 10(0) 2(0) */
1 struct changed
[acme@newtoy net-2.6.20]$
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
| -rw-r--r-- | include/linux/netdevice.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index caa3c259371..949eada46ce 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -196,7 +196,7 @@ struct hh_cache * NOTE: For VLANs, this will be the * encapuslated type. --BLG */ - int hh_len; /* length of header */ + u16 hh_len; /* length of header */ int (*hh_output)(struct sk_buff *skb); rwlock_t hh_lock; |