Messages in this thread | | | Subject | Re: hardware time stamping with optional structs in data area | From | Patrick Ohly <> | Date | Wed, 28 Jan 2009 10:52:13 +0100 |
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On Wed, 2009-01-28 at 11:08 +0200, Herbert Xu wrote: > Patrick Ohly <patrick.ohly@intel.com> wrote: > > > > True - at this time. But what if this extension mechanism turns out to > > be useful and we end up with more optional structures? I was hoping that > > this might be the case and thus tried to make it easy to add more > > structures. > > You're putting the extension in the skb->end area, right?
Right.
> How big are the time stamps? If they're not that big, why don't > we put it into the shinfo structure itself? For the common case, > we have plenty of space due to kmalloc padding anyway.
Two 64 bit fields have to be added for time stamps plus 3 bits for flags (for time stamping instructions, currently in skb_shared_tx).
Putting that into shinfo should work fine. I thought extending that structure with information that isn't needed for all packets was as bad as extending sk_buff itself. If that isn't the case, then extending shinfo definitely is the simplest solution.
Bye, Patrick
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