svn commit: r357002 - in head: share/man/man4 sys/conf sys/kern sys/modules/cpufreq sys/sys sys/x86/cpufreq

[Conrad Meyer]

(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 at freebsd.org> wrote:
>
> -----Original Message-----
> From: <owner-src-committers at freebsd.org> on behalf of Conrad Meyer <cem at FreeBSD.org>
> Date: 2020-01-22, Wednesday at 15:28
> To: <src-committers at freebsd.org>, <svn-src-all at freebsd.org>, <svn-src-head at 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
>
>
>