Subject: Re: [PATCH 0/3] netfilter : 3 patches to boost ip_tables performance

From: Andi Kleen <[email-masked]>
Date: Wed, 28 Sep 2005 10:37:02 +0200

On Wednesday 28 September 2005 10:32, Harald Welte wrote:

> I totally agree, that from a current perspective, I think the concept of
> just loading a module (that has usage count 0) having severe impact on
> system performance is just wrong.  But then, users are used to the
> current behaviour for almost five years now. 

That doesn't mean it cannot be improved - and I think it should.

In a sense it's even getting worse: For example us losing the CONFIG
option to disable local conntrack (Patrick has disabled it some time ago 
without even a comment why he did it) has a really bad impact in some cases.

> Therefore: Let's do this right next time, but live with that fact for
> now.

Even with a "quite straight-forward" (quoting you) fix?

> Just imagine all those poor sysadmins who know nothing about current
> kernel development, and who upgrade their kernel because their
> distributor provides a new one - suddenly their accounting (which might
> be relevant for their business) doesn't work anymore :(

Accounting with per CPU counters can be done fully lockless.

-Andi