Re: [Lse-tech] [RFC] [PATCH] Scalable Statistics Counters

Ravikiran G Thirumalai (kiran@in.ibm.com)
Thu, 6 Dec 2001 18:03:53 +0530


Hi Niels,

On Wed, Dec 05, 2001 at 10:02:33AM -0500, Niels Christiansen wrote:
>
> I'm wondering about the scope of this. My Ethernet adapter with, maybe, 20
> counter fields would have 20 counters allocated for each of my 16
> processors.
> The only way to get the total would be to use statctr_read() to merge them.
> Same for the who knows how many IP counters etc., etc.

Are you concerned with increase in memory used per counter Here? I suppose
that must not be that much of an issue for a 16 processor box....

>
> How many and which counters were converted for the test you refer to?
>

Well, I wrote a simple kernel module which just increments a shared global
counter a million times per processor in parallel, and compared it with
the statctr which would be incremented a million times per processor in
parallel..

> I do like the idea of a uniform access mechanism, though. It is well in
> line
> with my thoughts about an architected interface for topology and
> instrumentation
> so I'll definitely get back to you as I try to collect requirements.
>
> Niels

Hope we can come out with a really cool and acceptable interface..

Kiran

-- 
Ravikiran G Thirumalai <kiran@in.ibm.com>
Linux Technology Center, IBM Software Labs,
Bangalore.
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