From: Perry Yuan <perry.yuan@amd.com>
To: <rafael.j.wysocki@intel.com>, <Mario.Limonciello@amd.com>,
<Borislav.Petkov@amd.com>, <gautham.shenoy@amd.com>,
<viresh.kumar@linaro.org>, <Ray.Huang@amd.com>
Cc: <Alexander.Deucher@amd.com>, <Xinmei.Huang@amd.com>,
<Xiaojian.Du@amd.com>, <Perry.Yuan@amd.com>, <Li.Meng@amd.com>,
<linux-pm@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: [PATCH v9 7/7] Documentation: cpufreq: amd-pstate: update doc for Per CPU boost control method
Date: Mon, 6 May 2024 18:19:59 +0800 [thread overview]
Message-ID: <490ec11390350aa5814aa86a4e08cdefb7ce2832.1714989803.git.perry.yuan@amd.com> (raw)
In-Reply-To: <cover.1714989803.git.perry.yuan@amd.com>
Updates the documentation in `amd-pstate.rst` to include information about the
per CPU boost control feature. Users can now enable or disable the Core Performance
Boost (CPB) feature on individual CPUs using the `amd_pstate_boost_cpb`
sysfs attribute.
Signed-off-by: Perry Yuan <perry.yuan@amd.com>
---
Documentation/admin-guide/pm/amd-pstate.rst | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst
index bcc0d9404c18..8c48b00fc8a3 100644
--- a/Documentation/admin-guide/pm/amd-pstate.rst
+++ b/Documentation/admin-guide/pm/amd-pstate.rst
@@ -281,6 +281,27 @@ integer values defined between 0 to 255 when EPP feature is enabled by platform
firmware, if EPP feature is disabled, driver will ignore the written value
This attribute is read-write.
+``amd_pstate_boost_cpb``
+The `amd_pstate_boost_cpb` sysfs attribute provides control over the CPU core
+performance boost, allowing users to manage the maximum frequency limitation
+of the CPU. This attribute can be used to enable or disable the boost feature
+on individual CPUs.
+
+When the boost feature is enabled, the CPU can dynamically increase its frequency
+beyond the base frequency, providing enhanced performance for demanding workloads.
+On the other hand, disabling the boost feature restricts the CPU to operate at the
+base frequency, which may be desirable in certain scenarios to prioritize power
+efficiency or manage temperature.
+
+To manipulate the `amd_pstate_boost_cpb` attribute, users can write a value of `0`
+to disable the boost or `1` to enable it, for the respective CPU using the sysfs path
+`/sys/devices/system/cpu/cpuX/cpufreq/amd_pstate_boost_cpb`, where `X` represents the
+CPU number.
+
+It is important to note that modifying the global variable
+`amd_pstate_global_params.cpb_boost` will override the individual CPU settings.
+
+
Other performance and frequency values can be read back from
``/sys/devices/system/cpu/cpuX/acpi_cppc/``, see :ref:`cppc_sysfs`.
--
2.34.1
prev parent reply other threads:[~2024-05-06 10:20 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-06 10:19 [PATCH v9 0/7] AMD Pstate Driver Core Performance Boost Perry Yuan
2024-05-06 10:19 ` [PATCH v9 1/7] cpufreq: acpi: move MSR_K7_HWCR_CPB_DIS_BIT into msr-index.h Perry Yuan
2024-05-06 10:19 ` [PATCH v9 2/7] cpufreq: amd-pstate: initialize new core precision boost state Perry Yuan
2024-05-06 10:19 ` [PATCH v9 3/7] cpufreq: amd-pstate: implement cpb_boost sysfs entry for boost control Perry Yuan
2024-05-06 13:27 ` Limonciello, Mario
2024-05-06 15:01 ` Yuan, Perry
2024-05-06 10:19 ` [PATCH v9 4/7] cpufreq: amd-pstate: fix the MSR highest perf will be reset issue while cpb boost off Perry Yuan
2024-05-06 10:19 ` [PATCH v9 5/7] Documentation: cpufreq: amd-pstate: introduce the new cpu boost control method Perry Yuan
2024-05-06 10:19 ` [PATCH v9 6/7] cpufreq: amd-pstate: introduce per CPU frequency boost control Perry Yuan
2024-05-06 13:29 ` Limonciello, Mario
2024-05-06 10:19 ` Perry Yuan [this message]
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