On Sun, 23 Dec 2007 15:02:53 -0500
"Steven M. Bellovin" <smb@cs.columbia.edu> wrote:

> I'm having trouble with wm0 on two different Thinkpads, both running
> very recent kernels.  For one thing, they're slower than they used to
> be.  I could manage 550M-580M bps using from them to a Dell with bge0;
> now, I rarely hit 350M bps and I'm under 200M bps going from one to
> the other.  Second, both machines sometimes seem to forget how to
> talk on them, until I ifconfig the interface down and up.  On one, I
> could reliably trigger it by displaying Youtube videos, which I
> really don't understand...  My suspicion is that it's losing
> interrupts, or possibly that there's a timer issue.
> 
> Is anyone else seeing that?
> 
The problem appears to be from 1.150 of if_wm.c; when I revert it to
1.149, my speed doubles.  The commit message refers to 82543 and newer
chips, and claims a 4x speed improvement.  My problems are on an 82801H
and a 82540EP.


		--Steve Bellovin, http://www.cs.columbia.edu/~smb