On 11/30/2015 02:58 PM, David Miller wrote:

If you guys, really anyone, can find a way to remove some other 32-bit 
item from sk_buff, you can expand skb->mark to 64-bits. But otherwise, 
I'm going to be strongly against it. sk_buff is already enormous and 
larger than it should be. So I'm going to resist any change that makes 
it even larger. Thanks. 

Would the level of objection be the same if this was done as an 
"extended mark" field under a configurable off-by-default option? This 
would allow users who need this functionality to enable it while making 
it clear that this is at the expense of increasing sk_buff size.