[INET6]: Reorganize struct inet6_dev to save 8 bytes
And make it a multiple of a 64 bytes, reducing cacheline trashing:
Before:
[acme@doppio net-2.6]$ pahole -C inet6_dev net/dccp/ipv6.o
struct inet6_dev {
<SNIP>
long unsigned int mc_maxdelay; /* 48 8 */
unsigned char mc_qrv; /* 56 1 */
unsigned char mc_gq_running; /* 57 1 */
unsigned char mc_ifc_count; /* 58 1 */
/* XXX 5 bytes hole, try to pack */
/* --- cacheline 1 boundary (64 bytes) --- */
struct timer_list mc_gq_timer; /* 64 48 */
<SNIP>
__u32 if_flags; /* 180 4 */
int dead; /* 184 4 */
u8 rndid[8]; /* 188 8 */
/* XXX 4 bytes hole, try to pack */
/* --- cacheline 3 boundary (192 bytes) was 8 bytes ago --- */
struct timer_list regen_timer; /* 200 48 */
<SNIP>
/* size: 456, cachelines: 8 */
/* sum members: 447, holes: 2, sum holes: 9 */
/* last cacheline: 8 bytes */
};
After:
net-2.6/net/ipv6/af_inet6.c:
struct inet6_dev | -8
1 struct changed
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/if_inet6.h b/include/net/if_inet6.h
index b24508a..66c43e2 100644
--- a/include/net/if_inet6.h
+++ b/include/net/if_inet6.h
@@ -166,11 +166,11 @@
struct ifmcaddr6 *mc_list;
struct ifmcaddr6 *mc_tomb;
rwlock_t mc_lock;
- unsigned long mc_v1_seen;
- unsigned long mc_maxdelay;
unsigned char mc_qrv;
unsigned char mc_gq_running;
unsigned char mc_ifc_count;
+ unsigned long mc_v1_seen;
+ unsigned long mc_maxdelay;
struct timer_list mc_gq_timer; /* general query timer */
struct timer_list mc_ifc_timer; /* interface change timer */