ndt-users list created

[Ralf Hildebrandt <>]

* Richard Carlson 
<>:
> Ralf;
> 
> One comment on the bottleneck link detection.  Then NDT server needs
> to process every packet as it arrives.  Most Gigabit NICs default to
> using interrupt coalescing schemes to reduce the CPU overhead.  You
> must turn this feature off on the NDT server so the ndtd process sees
> every packet when it arrives.  The ethtool utility can be used to
> turn off this feature.

ok! I will try this.

> sudo ethtool -c eth0  (show the coalescing values for eth0)

# ethtool -c eth0
Coalesce parameters for eth0:
Adaptive RX: off  TX: off
stats-block-usecs: 999936
sample-interval: 0
pkt-rate-low: 0
pkt-rate-high: 0

rx-usecs: 18
rx-frames: 6
rx-usecs-irq: 18
rx-frames-irq: 6

tx-usecs: 80
tx-frames: 20
tx-usecs-irq: 80
tx-frames-irq: 20

rx-usecs-low: 0
rx-frame-low: 0
tx-usecs-low: 0
tx-frame-low: 0

rx-usecs-high: 0
rx-frame-high: 0
tx-usecs-high: 0
tx-frame-high: 0

> sudo ethtool -C rx-frames 1 eth0 (disable coalescing on eth0)

# ethtool -C rx-frames 1 eth0
Cannot get device coalesce settings: No such device

but
# ethtool -C eth0 rx-frames 1
seems to work

-- 
Ralf Hildebrandt
  Geschäftsbereich IT | Abteilung Netzwerk
  Charité - Universitätsmedizin Berlin
  Campus Benjamin Franklin
  Hindenburgdamm 30 | D-12203 Berlin
  Tel. +49 30 450 570 155 | Fax: +49 30 450 570 962
  

 | http://www.charite.de