From mboxrd@z Thu Jan  1 00:00:00 1970
From: "David S. Miller" <davem@davemloft.net>
Subject: Re: RFC: NAPI packet weighting patch
Date: Fri, 03 Jun 2005 11:49:50 -0700 (PDT)
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From: Ben Greear <greearb@candelatech.com>
Date: Fri, 03 Jun 2005 11:33:00 -0700

> Is this implying that having the NAPI poll do less work per poll
> of the driver actually increases performance?  I would have guessed that
> the opposite would be true.

Exactly my thoughts as well :)

> Maybe the poll is disabling the IRQs on the NIC for too long, or something
> like that?

In a reply I just sent out to this thread, I postulate that the
jiffies check is hitting earlier with a lower weight value, a quick
look at /proc/net/softnet_stat during their testing will confirm or
deny this theory.

It could also just be a simple bug in the dev->quota accounting
somewhere.

Note that, in all of this, I do not have any objections to providing
a way to configure the dev->weight values.  I will be applying Stephen
Hemminger's patches.

But I think we MUST find out the reason for the observed behavior,
especially in the single-adapter case since the result is so illogical.
We could find an important bug in the NAPI implementation, or learn
something new about how NAPI behaves.