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From: Mario Limonciello <mario.limonciello@amd.com>
To: <perry.yuan@amd.com>, <gautham.shenoy@amd.com>
Cc: Linux PM <linux-pm@vger.kernel.org>,
	Mario Limonciello <mario.limonciello@amd.com>
Subject: [PATCH v14 4/5] Documentation: cpufreq: amd-pstate: update doc for Per CPU boost control method
Date: Mon, 24 Jun 2024 16:33:59 -0500	[thread overview]
Message-ID: <20240624213400.67773-5-mario.limonciello@amd.com> (raw)
In-Reply-To: <20240624213400.67773-1-mario.limonciello@amd.com>

From: Perry Yuan <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 `boost`
sysfs attribute.

Signed-off-by: Perry Yuan <perry.yuan@amd.com>
Co-developed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 Documentation/admin-guide/pm/amd-pstate.rst | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst
index f5ee81419a93..d0324d44f548 100644
--- a/Documentation/admin-guide/pm/amd-pstate.rst
+++ b/Documentation/admin-guide/pm/amd-pstate.rst
@@ -281,6 +281,22 @@ 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.
 
+``boost``
+The `boost` 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 `boost` 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/boost`, where `X` represents the CPU number.
+
 Other performance and frequency values can be read back from
 ``/sys/devices/system/cpu/cpuX/acpi_cppc/``, see :ref:`cppc_sysfs`.
 
-- 
2.43.0


  parent reply	other threads:[~2024-06-24 21:34 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-06-24 21:33 [PATCH v14 0/5] AMD Pstate Driver Core Performance Boost Mario Limonciello
2024-06-24 21:33 ` [PATCH v14 1/5] cpufreq: acpi: move MSR_K7_HWCR_CPB_DIS_BIT into msr-index.h Mario Limonciello
2024-06-24 21:33 ` [PATCH v14 2/5] cpufreq: amd-pstate: initialize core precision boost state Mario Limonciello
2024-06-24 21:33 ` [PATCH v14 3/5] cpufreq: amd-pstate: Cap the CPPC.max_perf to nominal_perf if CPB is off Mario Limonciello
2024-06-24 21:33 ` Mario Limonciello [this message]
2024-06-25 12:03   ` [PATCH v14 4/5] Documentation: cpufreq: amd-pstate: update doc for Per CPU boost control method Gautham R.Shenoy
2024-06-24 21:34 ` [PATCH v14 5/5] cpufreq: Only disable boost during cpu online when using frequency tables Mario Limonciello
2024-06-25  6:30   ` Viresh Kumar
2024-06-25 12:31     ` Mario Limonciello
2024-06-26  3:11       ` Viresh Kumar
2024-06-26  3:14         ` Mario Limonciello
2024-06-26  3:17           ` Viresh Kumar
2024-06-26  3:20             ` Mario Limonciello
2024-06-26  3:25               ` Viresh Kumar
2024-06-26  3:27                 ` Viresh Kumar
2024-06-26  3:33                   ` Mario Limonciello
2024-06-26  3:44                     ` Viresh Kumar
2024-06-26  3:46                       ` Mario Limonciello
2024-06-25 11:55   ` Gautham R.Shenoy
2024-06-25 12:32     ` Mario Limonciello

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