Re: Route cache performance under stress

[Ralph Doncaster <ralph@xxxxxxxxx>]

On Tue, 10 Jun 2003, David S. Miller wrote:

>    From: Ralph Doncaster <ralph@xxxxxxxxx>
>    Date: Tue, 10 Jun 2003 19:58:47 -0400 (EDT)
>
>    On Tue, 10 Jun 2003, David S. Miller wrote:
>
>    > Every packet records a timestamp.
>
>    I'm not aware of anything in IP routing that requires a timestamp for
>    every packet.  To me it sounds like we could rip that out too.
>
> Guess you never run tcpdump nor use packet schedulers.

So because some (in the case of a core router almost none) of the packets
will need a timestamp, you do it for every single one of them?

This sounded so unbelievable to me that I took a quick look at the code to
see what I'd have to do to get rid of it.  It appears that gettimeofday is
not called for every packet; just for ICMP timestamp requests and for IP
options (ip_options_build and ip_options_compile).

-Ralph