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

Jeff V. Merkey
2006-03-31T17:49:13Z

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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