Date: Sun, 24 May 2015 00:15:18 +1000 (EST) From: Ian Smith <smithi@nimnet.asn.au> To: Kimmo Paasiala <kpaasial@gmail.com> Cc: "freebsd-stable@freebsd.org" <freebsd-stable@freebsd.org> Subject: Re: CPU frequency doesn't drop below 1200MHz (like it used to) Message-ID: <20150523234646.R7173@sola.nimnet.asn.au> In-Reply-To: <CA%2B7WWSf8q-Amwy60NSfC=_ZcguiTQN9qCmx9ArP4x9_zgTqq7A@mail.gmail.com> 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> <CA%2B7WWSfdC=P689XJeGjKCH49k4EVR7X5XR23_UeqGKy7mabVkw@mail.gmail.com> <20150523163014.U7173@sola.nimnet.asn.au> <CA%2B7WWSf8q-Amwy60NSfC=_ZcguiTQN9qCmx9ArP4x9_zgTqq7A@mail.gmail.com>
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On Sat, 23 May 2015 14:01:16 +0300, Kimmo Paasiala wrote: > On Sat, May 23, 2015 at 10:00 AM, Ian Smith <smithi@nimnet.asn.au> wrote: > > On Fri, 22 May 2015 20:26:40 +0300, Kimmo Paasiala wrote: > > > 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: > > [..] > > > >> Try changing the options in /boot/device.hints > > > >> hint.acpi_throttle.0.disabled="0" > > > >> hint.p4tcc.0.disabled="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? > > [..] > > > > 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. > > > > Ok, if anabling acpi_throttle and/or p4tcc made cpufreq - and thus > > powerd - work for you, then it seems likely that you do not have EST > > enabled in your BIOS. Or at least, we've seen another instance where > > that was the case, which was fixed by enabling EST (or however your > > particular BIOS refers to it .. AMD for example use different terms). > > > > What CPU is this? In what machine? > > > > If EST (ono) IS enabled in your BIOS, this needs further investigation. > > > > As is, powerd may be running, but it's doing so highly inefficiently; > > refer to Stefan, Adrian and Kevin's responses for details. > It's an Intel Atom running amd64 version of FreeBSD stable/10: > > FreeBSD firewall.rdnzl.info 10.1-STABLE FreeBSD 10.1-STABLE #1 > r283292: Sat May 23 01:08:03 EEST 2015 > root@firewall.rdnzl.info:/usr/obj/usr/src/sys/GENERIC amd64 > > CPU: Intel(R) Atom(TM) CPU D510 @ 1.66GHz (1666.68-MHz K8-class CPU) > Origin="GenuineIntel" Id=0x106ca Family=0x6 Model=0x1c Stepping=10 > Features=0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE> > Features2=0x40e31d<SSE3,DTES64,MON,DS_CPL,TM2,SSSE3,CX16,xTPR,PDCM,MOVBE> > AMD Features=0x20100800<SYSCALL,NX,LM> > AMD Features2=0x1<LAHF> > TSC: P-state invariant, performance statistics > > Powerd was working on 10.1-RELEASE but stopped working after upgrade > to 10-STABLE and nothing was changed in BIOS settings. Which would be consistent with EST not being enabled in your BIOS; with no EST, cpufreq(4) still checks for 'relative' drivers such as p4tcc or acpi_throttle and uses that, as a last resort really; with those also disabled, no cpufreq, so no powerd. Have you checked BIOS settings to confirm that you do have SpeedStep (however termed) properly enabled? Please show `sysctl dev.cpu dev.est` and `sysctl -a | grep freq_levels` > However, reading the other replies to this thread I get the impression > that powerd(8) doesn't actually save energy on this platform and I'm > better off without it? No, I don't think that's correct; using deeper C-states is most likely a bigger win, but higher than needed CPU freq will still use extra power, so run hotter. `sysctl dev.cpu` will also reveal your C-state usage. Reason I'm pursuing this is that this change shouldn't hurt, but it will flush out those cases where people were only getting cpufreq due to use of a 'relative' cpufreq driver like p4tcc, unless EST's enabled in BIOS; I suspect yours may be one such case :) If not, there's a bug to fix. cheers, Ian
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