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Be explicit about amd-pstate support

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Resolves: RHEL-16469

Since intel_pstate and amd-pstate use the same per-CPU interface
for setting EPP hints, the current cpu plugin supports amd-pstate
out of the box.

This commit modifies current P-state related logs and variable
names to be explicit about the support for amd-pstate.

Note that while intel_pstate supports global attributes such as
`max_perf_pct`, amd-pstate does not.
This commit is contained in:
Pavol Žáčik 2023-11-16 12:26:40 +01:00
parent 1460175f08
commit f03e1d0d24
No known key found for this signature in database
GPG key ID: B99527D5E6487A92
1 changed files with 22 additions and 11 deletions
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33
tuned/plugins/plugin_cpu.py
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@ -81,7 +81,8 @@ class CPULatencyPlugin(hotplug.Plugin):
`energy_performance_preference`:::
[option]`energy_performance_preference` supports managing energy
vs. performance hints on some newer Intel processors. Multiple alternative
vs. performance hints on newer Intel and AMD processors with active P-State
CPU scaling drivers (intel_pstate or amd-pstate). Multiple alternative
Energy Performance Preferences (EPP) values are supported. The alternative
values are separated using the '|' character. Available values can be found
in `energy_performance_available_preferences` file in `CPUFreq` policy
@ -196,6 +197,7 @@ class CPULatencyPlugin(hotplug.Plugin):
self._is_amd = False
self._has_energy_perf_bias = False
self._has_intel_pstate = False
self._has_amd_pstate = False
self._has_pm_qos_resume_latency_us = None
self._min_perf_pct_save = None
@ -256,12 +258,16 @@ class CPULatencyPlugin(hotplug.Plugin):
else:
log.info("We are running on %s (non x86)" % self._arch)
if self._is_intel is True:
if self._is_intel:
# Check for x86_energy_perf_policy, ignore if not available / supported
self._check_energy_perf_bias()
# Check for intel_pstate
self._check_intel_pstate()
if self._is_amd:
# Check for amd-pstate
self._check_amd_pstate()
def _check_energy_perf_bias(self):
self._has_energy_perf_bias = False
retcode_unsupported = 1
@ -281,6 +287,11 @@ class CPULatencyPlugin(hotplug.Plugin):
if self._has_intel_pstate:
log.info("intel_pstate detected")
def _check_amd_pstate(self):
self._has_amd_pstate = os.path.exists("/sys/devices/system/cpu/amd_pstate")
if self._has_amd_pstate:
log.info("amd-pstate detected")
def _get_cpuinfo_flags(self):
if self._flags is None:
self._flags = procfs.cpuinfo().tags.get("flags", [])
@ -580,7 +591,7 @@ class CPULatencyPlugin(hotplug.Plugin):
return_err = True)
return (retcode, err_msg)
def _intel_preference_path(self, cpu_id, available = False):
def _pstate_preference_path(self, cpu_id, available = False):
return "/sys/devices/system/cpu/cpufreq/policy%s/energy_performance_%s" % (cpu_id, "available_preferences" if available else "preference")
def _energy_perf_bias_path(self, cpu_id):
@ -736,13 +747,13 @@ class CPULatencyPlugin(hotplug.Plugin):
log.debug("%s is not online, skipping" % device)
return None
cpu_id = device.lstrip("cpu")
if os.path.exists(self._intel_preference_path(cpu_id, True)):
if os.path.exists(self._pstate_preference_path(cpu_id, True)):
vals = energy_performance_preference.split('|')
if not sim:
avail_vals = set(self._cmd.read_file(self._intel_preference_path(cpu_id, True)).split())
avail_vals = set(self._cmd.read_file(self._pstate_preference_path(cpu_id, True)).split())
for val in vals:
if val in avail_vals:
self._cmd.write_to_file(self._intel_preference_path(cpu_id), val)
self._cmd.write_to_file(self._pstate_preference_path(cpu_id), val)
log.info("Setting energy_performance_preference value '%s' for cpu '%s'" % (val, device))
break
else:
@ -752,7 +763,7 @@ class CPULatencyPlugin(hotplug.Plugin):
% device)
return str(energy_performance_preference)
else:
log.debug("energy_performance_available_preferences file missing, which can happen if the system is booted without the intel_pstate driver.")
log.debug("energy_performance_available_preferences file missing, which can happen if the system is booted without a P-state driver.")
return None
@command_get("energy_performance_preference")
@ -761,9 +772,9 @@ class CPULatencyPlugin(hotplug.Plugin):
log.debug("%s is not online, skipping" % device)
return None
cpu_id = device.lstrip("cpu")
# intel_pstate CPU scaling driver
if os.path.exists(self._intel_preference_path(cpu_id, True)):
return self._cmd.read_file(self._intel_preference_path(cpu_id)).strip()
# read the EPP hint used by the intel_pstate and amd-pstate CPU scaling drivers
if os.path.exists(self._pstate_preference_path(cpu_id, True)):
return self._cmd.read_file(self._pstate_preference_path(cpu_id)).strip()
else:
log.debug("energy_performance_available_preferences file missing, which can happen if the system is booted without the intel_pstate driver.")
log.debug("energy_performance_available_preferences file missing, which can happen if the system is booted without a P-state driver.")
return None