Date: Mon, 5 Jan 2015 20:44:09 -0800 From: Kevin Oberman <rkoberman@gmail.com> To: Dan Lukes <dan@obluda.cz> Cc: "freebsd-acpi@freebsd.org" <freebsd-acpi@freebsd.org> Subject: Re: Haswell, i3, fail to acpi_throttle fail Message-ID: <CAN6yY1u0gGS0M0uHHZiOyN4Sq=qM8TO-%2BRDzcFyO0VNWDtH-Ng@mail.gmail.com> In-Reply-To: <54AB5FFB.3090700@obluda.cz> References: <54AB32AD.1070409@ignoranthack.me> <CAN6yY1vnSLi7%2B0beSSC5awJtZ%2Bt4iWBOcery8Z%2Bt=Wki9LyJBg@mail.gmail.com> <54AB5FFB.3090700@obluda.cz>
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On Mon, Jan 5, 2015 at 8:09 PM, Dan Lukes <dan@obluda.cz> wrote: > On 6.1.2015 4:57, Kevin Oberman wrote: > >> acpi_throttle0: <ACPI CPU Throttling> on cpu0 >>> acpi_throttle0: P_CNT from P_BLK 0x1810 >>> est0: <Enhanced SpeedStep Frequency Control> on cpu0 >>> acpi_throttle1: <ACPI CPU Throttling> on cpu1 >>> acpi_throttle1: failed to attach P_CNT >>> device_attach: acpi_throttle1 attach returned 6 >>> >> > Attach to cpu0 successful, but failing on non-zero cpu's ? > > I never tried to analyze it, but I can deny it new issue. > > I never seen other result as far as I remember. > > Dan > I missed that it attached on cpu0. I think this is reality if throttling is done as it was in older CPUs. It required 3 physical pins on the CPU and predates (by some time) multi-core processors. Throttling in FreeBSD refers only to the old external form and is not related in any way to TCC, ST, or EST, all of which also do dynamic CPU Throttling, but in much more effective ways. Since throttling used physical pins, I have doubts that multi-core processors actually allocate three pins per CPU for a technique that is totally obsolete. It might be implemented as a compatibility thing and is really just TCC in disguise or they allocate three pins per chip and throttle all CPUs at once. If it is the latter, the behavior of only one CPU attaching is really more realistic than throttling per CPU. In either case, it is still best to disable it. -- R. Kevin Oberman, Network Engineer, Retired E-mail: rkoberman@gmail.com
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