Re: [PATCH v2] Documentation: admin-guide: pm: Add Out of Band mode

From: Rafael J. Wysocki
Date: Wed May 25 2022 - 09:50:21 EST


On Mon, May 23, 2022 at 8:17 PM Srinivas Pandruvada
<srinivas.pandruvada@xxxxxxxxxxxxxxx> wrote:
>
> Update documentation for using the tool to support performance level
> change via OOB (Out of Band) interface.
>
> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
> ---
> v2:
> As suggested by Jonathan
> - Indent literal block
> - Show output of command
>
> .../admin-guide/pm/intel-speed-select.rst | 22 +++++++++++++++++++
> 1 file changed, 22 insertions(+)
>
> diff --git a/Documentation/admin-guide/pm/intel-speed-select.rst b/Documentation/admin-guide/pm/intel-speed-select.rst
> index 0a1fbdb54bfe..a2bfb971654f 100644
> --- a/Documentation/admin-guide/pm/intel-speed-select.rst
> +++ b/Documentation/admin-guide/pm/intel-speed-select.rst
> @@ -262,6 +262,28 @@ Which shows that the base frequency now increased from 2600 MHz at performance
> level 0 to 2800 MHz at performance level 4. As a result, any workload, which can
> use fewer CPUs, can see a boost of 200 MHz compared to performance level 0.
>
> +Changing performance level via BMC Interface
> +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> +
> +It is possible to change SST-PP level using out of band (OOB) agent (Via some
> +remote management console, through BMC "Baseboard Management Controller"
> +interface). This mode is supported from the Sapphire Rapids processor
> +generation. The kernel and tool change to support this mode is added to Linux
> +kernel version 5.18. To enable this feature, kernel config
> +"CONFIG_INTEL_HFI_THERMAL" is required. The minimum version of the tool
> +is "v1.12" to support this feature, which is part of Linux kernel version 5.18.
> +
> +To support such configuration, this tool can be used as a daemon. Add
> +a command line option --oob::
> +
> + # intel-speed-select --oob
> + Intel(R) Speed Select Technology
> + Executing on CPU model:143[0x8f]
> + OOB mode is enabled and will run as daemon
> +
> +In this mode the tool will online/offline CPUs based on the new performance
> +level.
> +
> Check presence of other Intel(R) SST features
> ---------------------------------------------
>
> --

Applied as 5.19-rc material, thanks!