xen-devel.lists.xenproject.org archive mirror
 help / color / mirror / Atom feed
* [PATCH 00/13] Intel Hardware P-States (HWP) support
@ 2021-05-03 19:27 Jason Andryuk
  2021-05-03 19:27 ` [PATCH 01/13] cpufreq: Allow restricting to internal governors only Jason Andryuk
                   ` (13 more replies)
  0 siblings, 14 replies; 44+ messages in thread
From: Jason Andryuk @ 2021-05-03 19:27 UTC (permalink / raw)
  To: xen-devel
  Cc: Jason Andryuk, Jan Beulich, Andrew Cooper, Roger Pau Monné,
	Wei Liu, George Dunlap, Ian Jackson, Julien Grall,
	Stefano Stabellini, Community Manager

Hi,

This patch series adds Hardware-Controlled Performance States (HWP) for
Intel processors to Xen.

With HWP, the processor makes its own determinations for frequency
selection depending, though users can set some parameters and
preferences.  There is also Turbo Boost which dynamically pushes the max
frequency if possible.

The existing governors don't work with HWP since they select frequencies
and HWP doesn't expose those.  Therefore a dummy hwp-interal governor is
used that doesn't do anything.

xenpm get-cpufreq-para is extended to show HWP parameters, and
set-cpufreq-hwp is added to set them.

A lightly loaded OpenXT laptop showed ~1W power savings according to
powertop.  A mostly idle Fedora system (dom0 only) showed a more modest
power savings.

This for for a 10th gen 6-core 1600 MHz base 4900 MHZ max cpu.  In the
default balance mode, Turbo Boost doesn't exceed 4GHz.  Tweaking the
energy_perf preference with `xenpm set-cpufreq-hwp balance ene:64`,
I've seen the CPU hit 4.7GHz before throttling down and bouncing around
between 4.3 and 4.5 GHz.  Curiously the other cores read ~4GHz when
turbo boost takes affect.  This was done after pinning all dom0 cores,
and using taskset to pin to vCPU/pCPU 11 and running a bash tightloop.

There are only minor changes since the RFC posting.  Typo fixes and a
few hunks have been folded into earlier patches.  I reordered "xenpm:
Factor out a non-fatal cpuid_parse variant" immediately before "xenpm:
Add set-cpufreq-hwp subcommand" where it is used.

Open questions:

HWP defaults to enabled and running in balanced mode.  This is useful
for testing, but should the old ACPI cpufreq driver remain the default?

This series unilaterally enables Hardware Duty Cycling (HDC) which is
another feature to autonomously powerdown things.  That is enabled if
HWP is enabled.  Maybe that want to be configurable?

I've only tested on an 8th gen and a 10th gen systems.  The don't have
fast MSR support, and they do have activity window and energy_perf
support.  So the respective other modes are untested.

This changes the systcl_pm_op hypercall, so that wants review.

I wanted to get this out since I know Qubes is also interested.

Regards,
Jason

Jason Andryuk (13):
  cpufreq: Allow restricting to internal governors only
  cpufreq: Add perf_freq to cpuinfo
  cpufreq: Export intel_feature_detect
  cpufreq: Add Hardware P-State (HWP) driver
  xenpm: Change get-cpufreq-para output for internal
  cpufreq: Export HWP parameters to userspace
  libxc: Include hwp_para in definitions
  xenpm: Print HWP parameters
  xen: Add SET_CPUFREQ_HWP xen_sysctl_pm_op
  libxc: Add xc_set_cpufreq_hwp
  xenpm: Factor out a non-fatal cpuid_parse variant
  xenpm: Add set-cpufreq-hwp subcommand
  CHANGELOG: Add Intel HWP entry

 CHANGELOG.md                              |   2 +
 docs/misc/xen-command-line.pandoc         |   9 +
 tools/include/xenctrl.h                   |   6 +
 tools/libs/ctrl/xc_pm.c                   |  18 +
 tools/misc/xenpm.c                        | 375 +++++++++++-
 xen/arch/x86/acpi/cpufreq/Makefile        |   1 +
 xen/arch/x86/acpi/cpufreq/cpufreq.c       |  15 +-
 xen/arch/x86/acpi/cpufreq/hwp.c           | 671 ++++++++++++++++++++++
 xen/drivers/acpi/pmstat.c                 |  30 +
 xen/drivers/cpufreq/cpufreq.c             |   4 +
 xen/drivers/cpufreq/utility.c             |   1 +
 xen/include/acpi/cpufreq/cpufreq.h        |   9 +
 xen/include/acpi/cpufreq/processor_perf.h |   5 +
 xen/include/asm-x86/cpufeature.h          |  11 +-
 xen/include/asm-x86/msr-index.h           |  17 +
 xen/include/public/sysctl.h               |  52 +-
 16 files changed, 1197 insertions(+), 29 deletions(-)
 create mode 100644 xen/arch/x86/acpi/cpufreq/hwp.c

-- 
2.30.2



^ permalink raw reply	[flat|nested] 44+ messages in thread

end of thread, other threads:[~2021-06-04  6:39 UTC | newest]

Thread overview: 44+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-05-03 19:27 [PATCH 00/13] Intel Hardware P-States (HWP) support Jason Andryuk
2021-05-03 19:27 ` [PATCH 01/13] cpufreq: Allow restricting to internal governors only Jason Andryuk
2021-05-26 13:18   ` Jan Beulich
2021-05-26 14:12     ` Jason Andryuk
2021-05-26 15:09       ` Jan Beulich
2021-05-26 16:44         ` Jason Andryuk
2021-05-03 19:27 ` [PATCH 02/13] cpufreq: Add perf_freq to cpuinfo Jason Andryuk
2021-05-26 13:24   ` Jan Beulich
2021-05-26 14:19     ` Jason Andryuk
2021-05-03 19:28 ` [PATCH 03/13] cpufreq: Export intel_feature_detect Jason Andryuk
2021-05-26 13:27   ` Jan Beulich
2021-05-26 14:44     ` Jason Andryuk
2021-05-26 15:11       ` Jan Beulich
2021-05-03 19:28 ` [PATCH 04/13] cpufreq: Add Hardware P-State (HWP) driver Jason Andryuk
2021-05-26 14:59   ` Jan Beulich
2021-05-27  7:23     ` Jan Beulich
2021-05-27 18:50     ` Jason Andryuk
2021-05-28  6:35       ` Jan Beulich
2021-06-03 11:55         ` Jason Andryuk
2021-06-04  6:39           ` Jan Beulich
2021-05-27  7:45   ` Jan Beulich
2021-05-03 19:28 ` [PATCH 05/13] xenpm: Change get-cpufreq-para output for internal Jason Andryuk
2021-05-26 15:21   ` Jan Beulich
2021-05-27  5:54     ` Jan Beulich
2021-05-03 19:28 ` [PATCH 06/13] cpufreq: Export HWP parameters to userspace Jason Andryuk
2021-05-27  7:55   ` Jan Beulich
2021-05-28 13:19     ` Jason Andryuk
2021-05-28 13:39       ` Jan Beulich
2021-05-03 19:28 ` [PATCH 07/13] libxc: Include hwp_para in definitions Jason Andryuk
2021-05-03 19:28 ` [PATCH 08/13] xenpm: Print HWP parameters Jason Andryuk
2021-05-27  8:02   ` Jan Beulich
2021-05-03 19:28 ` [PATCH 09/13] xen: Add SET_CPUFREQ_HWP xen_sysctl_pm_op Jason Andryuk
2021-05-27  8:33   ` Jan Beulich
2021-05-03 19:28 ` [PATCH 10/13] libxc: Add xc_set_cpufreq_hwp Jason Andryuk
2021-05-04  8:03   ` Jan Beulich
2021-05-04 11:31     ` Jason Andryuk
2021-05-27  9:45   ` Jan Beulich
2021-05-03 19:28 ` [PATCH 11/13] xenpm: Factor out a non-fatal cpuid_parse variant Jason Andryuk
2021-05-27  8:41   ` Jan Beulich
2021-05-03 19:28 ` [PATCH 12/13] xenpm: Add set-cpufreq-hwp subcommand Jason Andryuk
2021-05-27  9:46   ` Jan Beulich
2021-05-03 19:28 ` [PATCH 13/13] CHANGELOG: Add Intel HWP entry Jason Andryuk
2021-05-27  9:48   ` Jan Beulich
2021-05-20 14:57 ` [PATCH 00/13] Intel Hardware P-States (HWP) support Jan Beulich

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).