Messages in this thread | | | Date | Fri, 17 Aug 2007 13:39:56 -0700 (PDT) | From | Christoph Lameter <> | Subject | Re: [PATCH 7/7] Simple Performance Counters: SLUB instrumentation |
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On Fri, 17 Aug 2007, Mathieu Desnoyers wrote:
> Why do you printk inside the timing period ? Filling the printk buffers > or outputting on things such as serial console could really hurt your > results.
It was easier to code?
> I hope you run your system with idle=poll and without frequency scaling > at all, because otherwise your cycle count would be completely off on > many AMD and Intel CPUs. You can have a look at this (very rough) > document on the topic:
The cpu will definitely not be idle during these measurements and no frequency scaling is active. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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