Re: [PATCH]: e1000: prevent statistics from getting garbled duringreset.

[Jeff V. Merkey]

Linas Vepstas wrote:

> On Thu, Mar 30, 2006 at 09:14:56PM -0700, Jeffrey V. Merkey wrote:
>  
>
> > Yes, we need one. The adapter needs to maintain these stats from the
> > registers in the kernel structure and not
> > its own local variables. 
> >    
>
> Did you read the code to see what the adapter does with these stats? 
> Among other things, it uses them to adaptively modulate transmit rates 
> to avoid collisions. Just clearing the hardware-private stats will mess
> up that function.
>
>  
I noticed that.

> > That way, when someone calls to clear the stats
> > for testing and analysis purposes,
> > they zero out and are reset.
> >    
>
> 1) ifdown/ifup is guarenteed to to clear things. Try that.
>  
No, not dynamic. I'll patch the driver locally, thanks.

Jeff

> 2) What's wrong with taking deltas? Typical through-put performance
> measurement is done by pre-loading the pipes (i.e. running for
> a few minutes wihtout measuring, then starting the measurement).
> I'd think that snapshotting the numbers would be easier, and is 
> trivially doable in user-space. I guess I don't understand why 
> you need a new kernel featre to imlement this.
>
> --linas
>
>  

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