Date: Fri, 22 May 2015 20:26:40 +0300 From: Kimmo Paasiala <kpaasial@gmail.com> To: Ian Smith <smithi@nimnet.asn.au> Cc: Ivan Klymenko <fidaj@ukr.net>, Nikos Vassiliadis <nvass@gmx.com>, "freebsd-stable@freebsd.org" <freebsd-stable@freebsd.org> Subject: Re: CPU frequency doesn't drop below 1200MHz (like it used to) Message-ID: <CA%2B7WWSfdC=P689XJeGjKCH49k4EVR7X5XR23_UeqGKy7mabVkw@mail.gmail.com> In-Reply-To: <20150523014640.K7173@sola.nimnet.asn.au> References: <555C71C8.4080007@gmx.com> <555EDBBB.4090107@gmx.com> <20150522104213.4e083225@nonamehost.local> <CA%2B7WWSfnsKn1Z3n1KS39iFZ%2B22ZzLsCke7mtnP%2BSAZh6M_cxCg@mail.gmail.com> <20150523014640.K7173@sola.nimnet.asn.au>
next in thread | previous in thread | raw e-mail | index | archive | help
On Fri, May 22, 2015 at 8:19 PM, Ian Smith <smithi@nimnet.asn.au> wrote: > On Fri, 22 May 2015 16:28:49 +0300, Kimmo Paasiala wrote: > > On Fri, May 22, 2015 at 10:42 AM, Ivan Klymenko <fidaj@ukr.net> wrote: >> Fri, 22 May 2015 09:33:15 +0200 >> Nikos Vassiliadis <nvass@gmx.com> =D1=8F=D1=8F=D1=8F=D1=8F=D1=8F=D1=8F= =D1=8F=D1=8F=D1=8F=D1=8F=D1=8F=D1=8F=D1=8F=D1=8F: >> >>> Hi, >>> >>> I just noticed that my CPU's frequency doesn't support dropping >>> below 1200MHz. It used to be able to go down to 150MHz, if I am >>> not mistaken. I'd like it to go down to 600MHz via powerd, like >>> it used to go. This is a month's old 10-STABLE. >>> >>> > [nik@moby ~]$ sysctl dev.cpu.0.freq_levels >>> > dev.cpu.0.freq_levels: 2400/35000 2300/32872 2200/31127 2100/29417 >>> > 2000/27740 1900/26096 1800/24490 1700/22588 1600/21045 1500/19534 >>> > 1400/18055 1300/16611 1200/15194 >>> >>> This is the CPU: >>> > hw.model: Intel(R) Core(TM) i3-3110M CPU @ 2.40GHz >>> >>> Thanks in advance for any ideas, >>> Nikos >> >> Try changing the options in /boot/device.hints >> hint.acpi_throttle.0.disabled=3D"0" >> hint.p4tcc.0.disabled=3D"0" > > > Thanks, those also fixed powerd(8) for me that stopped working after > > upgrading to stable/10 from releng/10.1. Why are those setting > > suddenly needed now? > > > > -Kimmo > > Looks like the changes to these two hints, now defaulting to 1, > committed to -head some months ago has been merged to stable/10. > > Can you say exactly in what way powerd stopped working then? Powerd(8) complained (excerpt from dmesg -a): Starting powerd. powerd: no cpufreq(4) support -- aborting: No such file or directory /etc/rc: WARNING: failed to start powerd Putting those two settings in loader.conf and rebooting fixed the problem and powerd started working again apparently because cpufreq(4) device was available again. -Kimmo > > Except that the minimum frequency that may be set with powerd's -m > switch will be higher without p4tcc (or acpi_throttle) running, this > change shouldn't hurt powerd; if anything it should be more efficient, > as the lower p4tcc-generated frequencies don't save much if any power. > > If you compare dev.cpu.0.freq_levels, as above, both before and after > booting with the changed hints, you can see the ones due to p4tcc's use > of subfrequencies with factors of 1/8 to 7/8 of some base freq, but the > power use in milliWatts provided for these seems largely ficticious. > > On my Lenovo X200, Core2Duo 2.4GHz, idling on battery at 800MHz (minimum > EST freq) or at 100MHz using p4tcc draws almost exactly the same power, > about 7.6W measured from the battery - but responsiveness as performance > is required is a great deal better using just the base EST freqs; YMMV. > > This generally gets discussed on the freebsd-mobile and freebsd-acpi > lists; not sure if a deeper discussion of issues is warranted here. > > cheers, Ian
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CA%2B7WWSfdC=P689XJeGjKCH49k4EVR7X5XR23_UeqGKy7mabVkw>