Re: [PATCH net-next] netdevice.h: Align struct netdevices members
From: Eric Dumazet <hidden>
Date: 2011-05-10 03:53:20
Le lundi 09 mai 2011 à 20:42 -0700, Joe Perches a écrit :
Save a bit of space. Signed-off-by: Joe Perches <joe@perches.com> --- include/linux/netdevice.h | 8 ++++---- 1 files changed, 4 insertions(+), 4 deletions(-)
Hmm... correct alignements are far more important for this structure. Did you run benchmarks on 32bit and 64bit platforms ? BTW we have ____cacheline_aligned_in_smp markers, I am not even sure this patch saves space.
quoted hunk ↗ jump to hunk
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index d5de66a..0fcb86b 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h@@ -1020,9 +1020,6 @@ struct net_device { * part of the usual set specified in Space.c. */ - unsigned char if_port; /* Selectable AUI, TP,..*/ - unsigned char dma; /* DMA channel */ - unsigned long state; struct list_head dev_list;@@ -1141,13 +1138,16 @@ struct net_device { const struct header_ops *header_ops; unsigned int flags; /* interface flags (a la BSD) */ + unsigned int priv_flags; /* Like 'flags' but invisible to userspace. */ unsigned short gflags; - unsigned int priv_flags; /* Like 'flags' but invisible to userspace. */ unsigned short padded; /* How much padding added by alloc_netdev() */ unsigned char operstate; /* RFC2863 operstate */ unsigned char link_mode; /* mapping policy to operstate */ + unsigned char if_port; /* Selectable AUI, TP,..*/ + unsigned char dma; /* DMA channel */ + unsigned int mtu; /* interface MTU value */ unsigned short type; /* interface hardware type */ unsigned short hard_header_len; /* hardware hdr length */