On Thu, 2010-03-11 at 10:05 -0800, David Miller wrote:

From: "Michael Chan" <mchan@broadcom.com>
Date: Thu, 11 Mar 2010 09:49:56 -0800

quoted

On Wed, 2010-03-10 at 18:09 -0800, Brian Haley wrote:

quoted

quoted

quoted

I'm able to cause a netdev_watchdog timeout by changing the coalesce
settings on my bnx2, I built a little test program for it:

Do you run this program in a loop?  How quickly do you see the NETDEV
WATCHDOG?

It's run once, and we see it almost immediately after ETHTOOL_SCOALESCE.

What's the difference between running the test program and doing ethtool
-C?  Do you see the issue in either case?  I don't see the issue here
with ethtool -C.

Probably because the independent program runs faster and thus
can trigger races more easily.

That's what I thought, I thought he was running it in a loop and
triggering some race condition.  But he said he only ran it once.  His
program gets the coalesce settings, sleeps for 5 seconds, and then sets
the coalesce settings.

In any case, you should be trying to reproduce his problem with
his test program since he went through the effort of providing
one.

I just tried it and cannot reproduce the problem.

Brian, please provide more information.  Thanks.