From: Arnaldo Carvalho de Melo Date: Sun, 3 Feb 2008 12:06:59 +0000 (-0800) Subject: [INET6]: Reorganize struct inet6_dev to save 8 bytes X-Git-Tag: v2.6.25-rc1~1065^2~4 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4e7e5cfe3825b4d854fc005d784a6f551b3c039f;p=linux-2.6 [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 { 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 */ __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 */ /* 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 Signed-off-by: David S. Miller --- diff --git a/include/net/if_inet6.h b/include/net/if_inet6.h index b24508abb8..66c43e29ea 100644 --- a/include/net/if_inet6.h +++ b/include/net/if_inet6.h @@ -166,11 +166,11 @@ struct inet6_dev 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 */