• Eric Dumazet's avatar
    flow_dissector: use a 64bit load/store · 4d77d2b5
    Eric Dumazet authored
    
    
    Le lundi 28 novembre 2011 à 19:06 -0500, David Miller a écrit :
    > From: Dimitris Michailidis <dm@chelsio.com>
    > Date: Mon, 28 Nov 2011 08:25:39 -0800
    >
    > >> +bool skb_flow_dissect(const struct sk_buff *skb, struct flow_keys
    > >> *flow)
    > >> +{
    > >> +	int poff, nhoff = skb_network_offset(skb);
    > >> +	u8 ip_proto;
    > >> +	u16 proto = skb->protocol;
    > >
    > > __be16 instead of u16 for proto?
    >
    > I'll take care of this when I apply these patches.
    
    ( CC trimmed )
    
    Thanks David !
    
    Here is a small patch to use one 64bit load/store on x86_64 instead of
    two 32bit load/stores.
    
    [PATCH net-next] flow_dissector: use a 64bit load/store
    
    gcc compiler is smart enough to use a single load/store if we
    memcpy(dptr, sptr, 8) on x86_64, regardless of
    CONFIG_CC_OPTIMIZE_FOR_SIZE
    
    In IP header, daddr immediately follows saddr, this wont change in the
    future. We only need to make sure our flow_keys (src,dst) fields wont
    break the rule.
    Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    4d77d2b5