On Mon, 2011-09-19 at 15:27 -0700, Duyck, Alexander H wrote:

On 09/19/2011 02:00 PM, David Miller wrote:

quoted

From: Alexander Duyck<redacted>
Date: Mon, 19 Sep 2011 09:32:18 -0700

quoted

The fact is ixgbe has been using this parameter this way for over 2
years now and the main goal of this patch was just to synchronize how
things work on igb and ixgbe.

Our hardware doesn't have a mechanism for firing an interrupt after X
number of frames so instead we simply have modified things so that we
will only process X number of frames and then fire another
interrupt/poll if needed.  As such we aren't that far out of
compliance with the meaning of how this parameter is supposed to be
used.

All I can say is this was a huge mistake you therefore need to revert
the IXGBE change, these ethtool settings are not for changing NAPI or
software interrupt behavior.

And if you guys plan to be difficult on this and refuse to remove the
IXGBE bits, I'm letting you guys know ahead of time that I'll do it
for you.

If the hardware can't support this facility, neither should these
ethtool hooks, because the whole point is to avoid hardware interrupts
from firing using these parameters.

Propose new mechanisms to control NAPI behavior if you want.

I'll remove the ixgbe code if that is what you want.  It may be a month 
or so before I can get to it though since I am slammed with work so if 
you are in a hurry for it you might want to work with Jeff Kirsher to 
have the code removed.

Alex- I will work on this to resolve the issues the Ben and Dave have
pointed out.

As far as this current patch goes I honestly don't have the time to add 
or rewrite yet another ethtool interface so I will probably just see 
about dropping the ethtool portion of this patch and update the 
description in order to make it acceptable.

Thanks,

Alex