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Date:      Mon, 12 May 2014 08:14:08 -0700
From:      Adrian Chadd <adrian@freebsd.org>
To:        Kevin Oberman <rkoberman@gmail.com>
Cc:        Poul-Henning Kamp <phk@phk.freebsd.dk>, "freebsd-arch@freebsd.org" <freebsd-arch@freebsd.org>, Ian Smith <smithi@nimnet.asn.au>, "freebsd-acpi@freebsd.org" <freebsd-acpi@freebsd.org>
Subject:   Re: proposal: set default lid state to S3, performance/economy Cx states to Cmax
Message-ID:  <CAJ-VmomYEgyY%2BSBamSHanyQnUpCTceX28AJrvzS5f99JYeoSDA@mail.gmail.com>
In-Reply-To: <CAN6yY1s%2BLDGQSr5ce%2Bvt-iHxu2Pj%2BripAD9ScnNzFP6N65OB5w@mail.gmail.com>
References:  <CAJ-Vmo=mUtpjgVwNHg8af05vCxVchZdsaekR9_Wf-pOfFjnABQ@mail.gmail.com> <20140505011654.O11699@sola.nimnet.asn.au> <2223.1399233644@critter.freebsd.dk> <CAJ-Vmo=aCtMb-Tavz86GbwENiT5Oe1N8Ju7%2Bpw55XAZCWG3HEw@mail.gmail.com> <20140505153421.W11699@sola.nimnet.asn.au> <85787.1399271121@critter.freebsd.dk> <20140505163316.R11699@sola.nimnet.asn.au> <7681.1399629328@critter.freebsd.dk> <CAJ-VmokWmYOzxhbPyFfrCns=5Ys8NcENwnF5V4unT9QULAL%2Btg@mail.gmail.com> <CAN6yY1sKDcS=_iiy6GmSvKJ3-tw43ugPLwp0Smv3k8=ug7u2PQ@mail.gmail.com> <CAJ-VmomxxYFLCJ6ULjwRhe-Fg03U9RD8tQWt=xknVgrF395UJw@mail.gmail.com> <CAN6yY1s%2BLDGQSr5ce%2Bvt-iHxu2Pj%2BripAD9ScnNzFP6N65OB5w@mail.gmail.com>

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The documentation is uhm, what's on intel's (growing) blog post and responses:

https://software.intel.com/en-us/articles/intel-performance-counter-monitor-a-better-way-to-measure-cpu-utilization

Yes, we can / should add clearer documentation. I had to also go
hunting in the source to figure some of it out.

FREQ/AFREQ is just the current clock cycle counters / clock reference
counter (TSC).

Ie, a freq or afreq of 1.0 means the clock cycle counters == TSC counter.

FREQ takes the sleep state into account (ie, only counts _running_
cycles.) AFREQ doesn't. So FREQ gives you a good indication of the
running duty cycle versus the ideal maximum, and AFREQ tells you what
frequency the core is running at versus the reference frequency. An
AFREQ of < 1.0 means that the chip is underclocking that core. An
AFREQ of > 1.0 means turboboost is on and it's overclocking that core.


-a


On 11 May 2014 17:40, Kevin Oberman <rkoberman@gmail.com> wrote:
> On Fri, May 9, 2014 at 1:36 PM, Adrian Chadd <adrian@freebsd.org> wrote:
>>
>> cool!
>>
>> next;
>>
>> # pkg install intel-pcm
>> # kldload cpuctl
>> # pcm.x 1
>>
>> See what it reports.
>
>
> OK. Any documentation on what this is supposed to tell me? Some of it makes
> perfect sense and some baffles me.
>
> I see C-states of C1 and C6 when on AC and C1, C3, and C7 when on battery
> (and, of course, C0). FREQ vs. AFREQ look interesting, but I'm not sure I
> really understand the implications. The last few lines, from " PHYSICAL CORE
> IPC", are particularly mysterious to me. I can understand the words, but I
> think that they carry more significance than is obvious, at least to me. I'm
> not a hardware guy.
>  --
> R. Kevin Oberman, Network Engineer, Retired
> E-mail: rkoberman@gmail.com



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