Re: [PATCH] UDPCP Communication Protocol

Stephen Hemminger
2010-12-31T17:46:34Z

On Fri, 31 Dec 2010 10:29:45 +0100
stefani@seibold.net wrote:

> +struct __attribute__ ((packed)) udpcphdr {
> + struct udphdr udphdr;
> + __be32 chksum;
> + __be16 msginfo;
> + u8 fragamount;
> + u8 fragnum;
> + __be16 msgid;
> + __be16 length;
> +};

Adding (unnecessary) packed attribute will make access slow on
some architectures. For arch that can't do unaligned access, the
compiler ends up doing byte access for each element.