Re: issue with new TCP TSO stuff

["David S. Miller" <davem@xxxxxxxxxxxxx>]

From: Andi Kleen <ak@xxxxxx>
Subject: Re: issue with new TCP TSO stuff
Date: 12 May 2005 22:02:51 +0200,Thu, 12 May 2005 22:02:51 +0200

> Sure, but did you verify it was the actual problem? (e.g. with a profiler) 
> If the cache line the atomic operation is done on is EXCLUSIVE to the
> CPU then it should not take *that* long to do the atomic operations.

Such issues cannot be measured like that, they tend to make
other operations slower by inducing cache misses elsewhere.

I used my brain to analyze this slowdown, instead of the
computer, I'm sorry if that disturbs you :-)