Re: packet re-ordering on SMP machines.

[jamal <hadi@xxxxxxxxxx>]

On Mon, 26 Aug 2002, Xiaoliang (David) Wei wrote:

> Hi Ben and Jamal,
>        Are you guys sure that getdayoftime per packet is a big overhead on
> Gbps connection?

We may be talking about different things;
I am talking about do_gettimeofday -- which is very expensive.
Anyone who has time could look at improving that. It is run per incoming
packet.

>        Do you compare the performance with getdayoftime per packet and
> without?

I think it would be pretty noticeable if you got rid of the
per-incoming-packet calls to do_gettimeofday

> I guess RFC 1323 specifies that each packet should have a timestamp
> (although not from getdayoftime).

In Linux, this is cleverly based on the system clock (jiffies).

cheers,
jamal