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Re: [Xen-devel] performance counters

To: Jan Beulich <jbeulich@xxxxxxxxxx>, Keir Fraser <keir@xxxxxxxxxxxxx>
Subject: Re: [Xen-devel] performance counters
From: Keir Fraser <keir@xxxxxxxxxxxxx>
Date: Thu, 15 Mar 2007 15:03:15 +0000
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On 15/3/07 14:37, "Jan Beulich" <jbeulich@xxxxxxxxxx> wrote:

>> at least on architectures where we know the resulting incorrectness is not
>> 'too bad' (that includes x86). Some of the shared counters are on hot paths.
>> Alternatively we could make *all* counters per-cpu, even histogram counter
>> arrays.
> To me that would seem like the better alternative than dropping atomicity.

It has the added benefit of avoiding cacheline bouncing.

It just needs someone to implement this improvement. ;-)

 -- Keir

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