linux-kernel - [PATCH v3 5/5] Documentation: add amd-pstate kernel command line options

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20221117073541.3350600-6-Perry.Yuan@amd.com>
Date:   Thu, 17 Nov 2022 15:35:41 +0800
From:   Perry Yuan <Perry.Yuan@....com>
To:     <rafael.j.wysocki@...el.com>, <ray.huang@....com>,
        <viresh.kumar@...aro.org>, <Mario.Limonciello@....com>
CC:     <Nathan.Fontenot@....com>, <Alexander.Deucher@....com>,
        <Deepak.Sharma@....com>, <Shimmer.Huang@....com>,
        <Li.Meng@....com>, <Xiaojian.Du@....com>, <wyes.karny@....com>,
        <gautham.shenoy@....com>, <ananth.narayan@....com>,
        <linux-pm@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        Perry Yuan <Perry.Yuan@....com>
Subject: [PATCH v3 5/5] Documentation: add amd-pstate kernel command line options

Add a new amd pstate driver command line option to enable driver passive
working mode via MSR and shared memory interface to request desired
performance within abstract scale and the power management firmware
(SMU) convert the perf requests into actual hardware pstates.

Also the `disable` parameter can disable the pstate driver loading by
adding `amd_pstate=disable` to kernel command line.

Acked-by: Huang Rui <ray.huang@....com>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@....com>
Tested-by: Wyes Karny <wyes.karny@....com>
Signed-off-by: Perry Yuan <Perry.Yuan@....com>
---
 Documentation/admin-guide/kernel-parameters.txt | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index a465d5242774..42af9ca0127e 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -6959,3 +6959,14 @@
 				memory, and other data can't be written using
 				xmon commands.
 			off	xmon is disabled.
+
+	amd_pstate=	[X86]
+			disable
+			  Do not enable amd_pstate as the default
+			  scaling driver for the supported processors
+			passive
+			  Use amd_pstate as a scaling driver, driver requests a
+			  desired performance on this abstract scale and the power
+			  management firmware translates the requests into actual
+			  hardware states (core frequency, data fabric and memory
+			  clocks etc.)
-- 
2.25.1