NAPI increased performance?

NAPI increased performance?

Post by skris_ » Wed, 15 Oct 2003 01:55:46


I have shifted the source code of my SOHO router to kernel version
2.4.20 from 2.4.7. I wanted to see if this results in an improved
performance for IP forwarding. I have noticed that in fact there is
more than 30% increase in the IP forwarding performance.

What can I attribute for this increased performance of the device? I
know that starting from 2.4.20 NAPI is introduced which can improve
the performance. But I have not adapted my ethernet driver to a
NAPI-like driver. So, it still remains as a non-NAPI driver and hence
the packets get processed using the backlog queue itself (of course in
"process_backlog" function called from the SOFT IRQ).

Am I missing something here? Could someone explain me the reason for
this increased performance though the driver is a non-NAPI
conventional ethernet driver?