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: Thu, 12 May 2005 16:13:05 +0200

> Are you sure a few atomic_inc/dec are really causing noticeable
> slowdown? That would surprise me unless you have lots of cache line
> bouncing on a MP system.

It's about 7 or 8 times as many atomic gets and puts on pages compared
to the older code (with an 8K page size).

Some of it we can't get rid of, because we keep a normal write queue
segmented set of SKBs around.

But the TSO part we can eliminate.