On Sat, Jan 06, 2001 at 11:22:41PM -0700, Ben Greear wrote:
> At the time I was doing this, I downloaded the latest nettools version.
> The hashing made a very noticable difference on 4000 interfaces, but
> I haven't run any real solid benchmarkings at other levels. Can
> you tell me some distinguishing mark (version?) on ifconfig that I
> can look for?
Just get the latest release.
>
> I'm willing to run such benchmarks, but what would make a good benchmark,
> other than ifconfig -a?
ifconfig -a is fine IMHO. Everything else I know is just a single pass through
the lists (which even at 4000 is not very significant)
> Suppose I bind a raw socket to device vlan4001 (ie I have 4k in the list
> before that one!!). Currently, that means a linear search on all devices,
> right? In that extreme example, I would expect the hash to be very
> useful.
Nope, it doesn't. Raw binding works via IP addresses, and the IP address resolution
works via the routing table, which is extensively hashed.
Packet socket binding or SO_BINDTODEVICE will search the list, but it is unlikely
that these paths are worth optimizing for.
> Binding to IP addresses have the same issue??
No, uses the fib.
> Also, though hashing by name is not horribly exact, hashing on the device
> index should be nearly perfect, so finding device 666 might take a search
> through only 5 or so devices (find the hash-bucket, walk down the list in
> that bucket).
Just why? It is not in any critical path I can see at all.
-Andi
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This archive was generated by hypermail 2b29 : Sun Jan 07 2001 - 21:00:27 EST