Date: Thu, 23 Jan 2020 12:02:17 -0800 From: Conrad Meyer <cem@freebsd.org> To: Ravi Pokala <rpokala@freebsd.org> Cc: src-committers <src-committers@freebsd.org>, svn-src-all <svn-src-all@freebsd.org>, svn-src-head <svn-src-head@freebsd.org> Subject: Re: svn commit: r357002 - in head: share/man/man4 sys/conf sys/kern sys/modules/cpufreq sys/sys sys/x86/cpufreq Message-ID: <CAG6CVpVyVWk54NAifwx9kWOH8%2BKMh58PgSmSjhonB1%2BE0XyjUw@mail.gmail.com> In-Reply-To: <FC92092D-97B4-473A-B131-2E6BA6EC3118@panasas.com> References: <202001222328.00MNSh8a058358@repo.freebsd.org> <FC92092D-97B4-473A-B131-2E6BA6EC3118@panasas.com>
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(I had to look that up.) Yeah, they're different. Speedstep is est(4), the ~15-year old predecessor to Speedshift. They serve similar purposes but purportedly (and plausibly) Speedshift does a better job; also SpeedStep is maybe going away entirely in newer CPUs. Current gens like Skylake and Kabylake have silicon for both, but if intel_hwpstate(4) is enabled, est(4) doesn't work; hence the kludge in est(4) to avoid "identifying" if intel_hwpstate(4) successfully identified (wasn't disabled && new enough CPU). Best, Conrad On Thu, Jan 23, 2020 at 12:55 AM Ravi Pokala <rpokala@freebsd.org> wrote: > > -----Original Message----- > From: <owner-src-committers@freebsd.org> on behalf of Conrad Meyer <cem@FreeBSD.org> > Date: 2020-01-22, Wednesday at 15:28 > To: <src-committers@freebsd.org>, <svn-src-all@freebsd.org>, <svn-src-head@freebsd.org> > Subject: svn commit: r357002 - in head: share/man/man4 sys/conf sys/kern sys/modules/cpufreq sys/sys sys/x86/cpufreq > > Author: cem > Date: Wed Jan 22 23:28:42 2020 > New Revision: 357002 > URL: https://svnweb.freebsd.org/changeset/base/357002 > > Log: > cpufreq(4): Add support for Intel Speed Shift > > Intel Speed Shift is Intel's technology to control frequency in hardware, > with hints from software. > > Not to be confused with Intel Speed *Step*, right? > > (/me was confused; naming things is hard) > > -Ravi (rpokala@) > > Let's get a working version of this in the tree and we can refine it from > here. > > Submitted by: bwidawsk, scottph > Reviewed by: bcr (manpages), myself > Discussed with: jhb, kib (earlier versions) > With feedback from: Greg V, gallatin, freebsdnewbie AT freenet.de > Relnotes: yes > Differential Revision: https://reviews.freebsd.org/D18028 > > >
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