Subject: Re: [PATCH - RFC] [1/5] 64-bit network statistics - generic net

From: Jeff Sipek <[email-masked]>
Date: Sat, 05 Jul 2003 16:37:43 -0400

On Saturday 05 July 2003 15:58, Bernd Eckenfels wrote:
> a reader like ifconfig can easyly work around this with multiple tries, but
> incremeting those variables wont work that easy, and therefore needs a
> lock, which will be a major pita.
>
> 64bit counters should be a result of lockless per-cpu network counters
> (32bit) with some kind of async merging.

This is going to make the structure huge - not only you have the 32-bit 
variables for every CPU, but you have one global set of 64-bit variables 
(possibly you will need a lock for the 64-bit vars.)

Also another thing to consider is portability across architectures - we don't 
need all this code on 64-bit arches.

On the other hand, per-cpu stats may possibly make up for the extra code - no 
cache bouncing, etc.

> Or we wait till 64bit hardware is more common :)

Hehe, the thing is, that when 64bits beecome more common you will have this 
huge number of unused x86 computers that people will:

- - throw out
- - donate
- - convert to all sorts of "embedded" systems which need stable OS (read: 
Linux) (these include routers)

So, x86 is here to stay for some time.

Jeff.

- -- 
The Moon is Waxing Crescent (36% of Full)