leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Merge branch 'pm-docs'

Browse Source 
Merge PM documentation update for 5.19-rc1.

* pm-docs:
  Documentation: admin-guide: PM: Add Out of Band mode
This commit is contained in:
Rafael J. Wysocki 2022-05-30 15:40:37 +02:00
commit 1cdc5ba06d
1 changed files with 22 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
Documentation/admin-guide/pm/intel-speed-select.rst
View File

@ -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
---------------------------------------------