On Mon, 2008-12-01 at 10:37 +0000, Patrick Ohly wrote:

Oliver suggested:

quoted

What about just creating a new pointer in the struct skbuff that points 
to a struct hwstamp when it is available OR the pointer is NULL when no 
hwstamps are available.

[...]

So it seems to me that we need the additional 32 bit offset (or pointer,
on 32 bit architectures) in skb which points towards the struct
hwtstamp. But that's actually less than the additional 64 bit which hold
the time stamp value, as in the current patch.

It doesn't even need a 32 bit offset. If it is always at the same
location in the buffer (e.g., directly after skb_shared_info), then a
single bit is sufficient. The same mechanism could be used to also store
other optional structs/fields.

-- 
Best Regards, Patrick Ohly

The content of this message is my personal opinion only and although
I am an employee of Intel, the statements I make here in no way
represent Intel's position on the issue, nor am I authorized to speak
on behalf of Intel on this matter.