Simple click config is VERY slow on our system; also the PollDevice doesn't work on our tulip.

[Eric Freudenthal]

As I indicated earlier, we're building a router that imposes delays.  When
we just let linux forward, we see round-trip ping latencies of 200-300us.
When we insert the following minimal click config, we don't notice any
slow-down:

FromDevice(eth1) -> cc :: IPClassifier(src 1.1.1.1, dst 1.1.1.1, -);
cc[0] -> ToLinux;  // not used
cc[1] -> ToLinux;  // not used
cc[2]  // everything comes here
 -> ToLinux;

However, a that inserts 10 latency/bandwidth limiter blocks (see end of this
note) adds an amazing 10ms, with a very large variance (we often see
30-70ms).  As before, there is no network traffic other than the pings.

Also: the PollDevice(eth1) doesn't work for us (we're using a tulip nic)-
the click task fails, and the kernel becomes unstable as soon as we try.
(RH7.1, linux 2.2.19).  Perhaps we're building our kernel with a subtly
incompatible config?  Maybe we should try one of your configs; Could you tar
up a configured kernel source tree that works for us to try?

Thanks, Eric


- - - - - t e a r   h e r e - - - - -
FromDevice(eth1) -> cc :: IPClassifier(src 1.1.1.1, dst 1.1.1.1, -);
cc[0] -> ToLinux;
cc[1] -> ToLinux;
cc[2]

 -> IPClassifier(src 172.31.0.0/16) [0]
 -> Queue(256)
 -> BandwidthShaper(100000000)
 -> SetTimestamp
 -> DelayUnqueue(0.00001s)

 -> IPClassifier(src 172.31.0.0/16) [0]
 -> Queue(256)
 -> BandwidthShaper(100000000)
 -> SetTimestamp
 -> DelayUnqueue(0.00001s)

 -> IPClassifier(src 172.31.0.0/16) [0]
 -> Queue(256)
 -> BandwidthShaper(100000000)
 -> SetTimestamp
 -> DelayUnqueue(0.00001s)

 -> IPClassifier(src 172.31.0.0/16) [0]
 -> Queue(256)
 -> BandwidthShaper(100000000)
 -> SetTimestamp
 -> DelayUnqueue(0.00001s)

 -> IPClassifier(src 172.31.0.0/16) [0]
 -> Queue(256)
 -> BandwidthShaper(100000000)
 -> SetTimestamp
 -> DelayUnqueue(0.00001s)

 -> IPClassifier(src 172.31.0.0/16) [0]
 -> Queue(256)
 -> BandwidthShaper(100000000)
 -> SetTimestamp
 -> DelayUnqueue(0.00001s)

 -> IPClassifier(src 172.31.0.0/16) [0]
 -> Queue(256)
 -> BandwidthShaper(100000000)
 -> SetTimestamp
 -> DelayUnqueue(0.00001s)

 -> IPClassifier(src 172.31.0.0/16) [0]
 -> Queue(256)
 -> BandwidthShaper(100000000)
 -> SetTimestamp
 -> DelayUnqueue(0.00001s)

 -> IPClassifier(src 172.31.0.0/16) [0]
 -> Queue(256)
 -> BandwidthShaper(100000000)
 -> SetTimestamp
 -> DelayUnqueue(0.00001s)


-> ToLinux;