46ca5f5dc4
[acme@newtoy net-2.6.20]$ pahole net/ipv4/tcp.o xfrm_policy /* /pub/scm/linux/kernel/git/acme/net-2.6.20/include/linux/security.h:67 */ struct xfrm_policy { struct xfrm_policy * next; /* 0 4 */ struct hlist_node bydst; /* 4 8 */ struct hlist_node byidx; /* 12 8 */ rwlock_t lock; /* 20 36 */ atomic_t refcnt; /* 56 4 */ struct timer_list timer; /* 60 24 */ u8 type; /* 84 1 */ /* XXX 3 bytes hole, try to pack */ u32 priority; /* 88 4 */ u32 index; /* 92 4 */ struct xfrm_selector selector; /* 96 56 */ struct xfrm_lifetime_cfg lft; /* 152 64 */ struct xfrm_lifetime_cur curlft; /* 216 32 */ struct dst_entry * bundles; /* 248 4 */ __u16 family; /* 252 2 */ __u8 action; /* 254 1 */ __u8 flags; /* 255 1 */ __u8 dead; /* 256 1 */ __u8 xfrm_nr; /* 257 1 */ /* XXX 2 bytes hole, try to pack */ struct xfrm_sec_ctx * security; /* 260 4 */ struct xfrm_tmpl xfrm_vec[6]; /* 264 360 */ }; /* size: 624, sum members: 619, holes: 2, sum holes: 5 */ So lets have just one hole instead of two, by moving 'type' to just before 'action', end result: [acme@newtoy net-2.6.20]$ codiff -s /tmp/tcp.o.before net/ipv4/tcp.o /pub/scm/linux/kernel/git/acme/net-2.6.20/net/ipv4/tcp.c: struct xfrm_policy | -4 1 struct changed [acme@newtoy net-2.6.20]$ [acme@newtoy net-2.6.20]$ pahole -c 64 net/ipv4/tcp.o xfrm_policy /* /pub/scm/linux/kernel/git/acme/net-2.6.20/include/linux/security.h:67 */ struct xfrm_policy { struct xfrm_policy * next; /* 0 4 */ struct hlist_node bydst; /* 4 8 */ struct hlist_node byidx; /* 12 8 */ rwlock_t lock; /* 20 36 */ atomic_t refcnt; /* 56 4 */ struct timer_list timer; /* 60 24 */ u32 priority; /* 84 4 */ u32 index; /* 88 4 */ struct xfrm_selector selector; /* 92 56 */ struct xfrm_lifetime_cfg lft; /* 148 64 */ struct xfrm_lifetime_cur curlft; /* 212 32 */ struct dst_entry * bundles; /* 244 4 */ u16 family; /* 248 2 */ u8 type; /* 250 1 */ u8 action; /* 251 1 */ u8 flags; /* 252 1 */ u8 dead; /* 253 1 */ u8 xfrm_nr; /* 254 1 */ /* XXX 1 byte hole, try to pack */ struct xfrm_sec_ctx * security; /* 256 4 */ struct xfrm_tmpl xfrm_vec[6]; /* 260 360 */ }; /* size: 620, sum members: 619, holes: 1, sum holes: 1 */ Are there any fugly data dependencies here? None that I know. In the process changed the removed the __ prefixed types, that are just for userspace visible headers. Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> |
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.. | ||
acpi | ||
asm-alpha | ||
asm-arm | ||
asm-arm26 | ||
asm-avr32 | ||
asm-cris | ||
asm-frv | ||
asm-generic | ||
asm-h8300 | ||
asm-i386 | ||
asm-ia64 | ||
asm-m32r | ||
asm-m68k | ||
asm-m68knommu | ||
asm-mips | ||
asm-parisc | ||
asm-powerpc | ||
asm-ppc | ||
asm-s390 | ||
asm-sh | ||
asm-sh64 | ||
asm-sparc | ||
asm-sparc64 | ||
asm-um | ||
asm-v850 | ||
asm-x86_64 | ||
asm-xtensa | ||
crypto | ||
keys | ||
linux | ||
math-emu | ||
media | ||
mtd | ||
net | ||
pcmcia | ||
rdma | ||
rxrpc | ||
scsi | ||
sound | ||
video | ||
Kbuild |