linux-kernel - RE: [PATCH 0/3] Improve usability for amd-pstate

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] [day] [month] [year] [list]

Message-ID: <BL1PR12MB5157E8B3EF9E0F87629198F8E21D9@BL1PR12MB5157.namprd12.prod.outlook.com>
Date:   Mon, 28 Mar 2022 22:14:59 +0000
From:   "Limonciello, Mario" <Mario.Limonciello@....com>
To:     "Huang, Ray" <Ray.Huang@....com>
CC:     "Rafael J . Wysocki" <rafael@...nel.org>,
        Viresh Kumar <viresh.kumar@...aro.org>,
        "open list:AMD PSTATE DRIVER" <linux-pm@...r.kernel.org>,
        open list <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH 0/3] Improve usability for amd-pstate

[Public]



> -----Original Message-----
> From: Huang, Ray <Ray.Huang@....com>
> Sent: Sunday, March 27, 2022 06:56
> To: Limonciello, Mario <Mario.Limonciello@....com>
> Cc: Rafael J . Wysocki <rafael@...nel.org>; Viresh Kumar
> <viresh.kumar@...aro.org>; open list:AMD PSTATE DRIVER <linux-
> pm@...r.kernel.org>; open list <linux-kernel@...r.kernel.org>
> Subject: Re: [PATCH 0/3] Improve usability for amd-pstate
> 
> On Fri, Mar 25, 2022 at 01:42:25PM +0800, Limonciello, Mario wrote:
> > There has recently been some news coverage about `amd-pstate` being in
> > 5.17, but this news also mentioned that it's a bit difficult to use.
> >
> > You need to either block init calls, or compile the module into the kernel
> > to force it to take precedence over acpi-cpufreq.
> >
> > This series aims to improve the usability of amd-pstate so that distros
> > can compile as a module, but users can still use it (relatively) easily.
> >
> > A new module parameter is included that will force amd-pstate to take
> > precedence and a module table to let it load automatically on such systems.
> >
> > With the patches in this series a user can make a file
> > /etc/modprobe.d/amd-pstate.conf:
> >
> > options amd-pstate replace=1
> 
> Actually, because the amd-pstate is fairly new for current distos, we can
> modify /etc/modules-load.d/modules.conf to add one line "amd_pstate" to
> inform the system this module should be loaded at boot time.

Actually I don't believe that would work in the case that acpi-cpufreq is built-in
or gets loaded first.

> 
> But your method also looks fine for me as well, the amd-pstate can force to
> replace the acpi-cpufreq. I am not sure whether anyone objects to this way.

Thanks for your suggestions in the series, I'll adopt them for v2.

> 
> Thanks,
> Ray
> 
> >
> > Then upon the next reboot amd-pstate should load automatically even if
> > acpi-cpufreq was included on the system.
> > Mario Limonciello (3):
> >   cpufreq: Allow passing NULL as the argument for unregistering a driver
> >   cpufreq: amd-pstate: Allow replacing existing cpufreq drivers when
> >     loaded
> >   cpufreq: amd-pstate: Add a module device table
> >
> >  drivers/cpufreq/amd-pstate.c | 19 ++++++++++++++++---
> >  drivers/cpufreq/cpufreq.c    |  4 ++--
> >  2 files changed, 18 insertions(+), 5 deletions(-)
> >
> > --
> > 2.34.1
> >