|author||Lukasz Luba <email@example.com>||2020-11-03 09:05:58 +0000|
|committer||Rafael J. Wysocki <firstname.lastname@example.org>||2020-11-10 20:29:28 +0100|
PM: EM: Clarify abstract scale usage for power values in Energy Model
The Energy Model (EM) can store power values in milli-Watts or in abstract scale. This might cause issues in the subsystems which use the EM for estimating the device power, such as: - mixing of different scales in a subsystem which uses multiple (cooling) devices (e.g. thermal Intelligent Power Allocation (IPA)) - assuming that energy [milli-Joules] can be derived from the EM power values which might not be possible since the power scale doesn't have to be in milli-Watts To avoid misconfiguration add the requisite documentation to the EM and related subsystems: EAS and IPA. Signed-off-by: Lukasz Luba <email@example.com> Signed-off-by: Rafael J. Wysocki <firstname.lastname@example.org>
Diffstat (limited to 'Documentation/scheduler')
1 files changed, 5 insertions, 0 deletions
diff --git a/Documentation/scheduler/sched-energy.rst b/Documentation/scheduler/sched-energy.rst
index 001e09c95e1d..afe02d394402 100644
@@ -350,6 +350,11 @@ independent EM framework in Documentation/power/energy-model.rst.
Please also note that the scheduling domains need to be re-built after the
EM has been registered in order to start EAS.
+EAS uses the EM to make a forecasting decision on energy usage and thus it is
+more focused on the difference when checking possible options for task
+placement. For EAS it doesn't matter whether the EM power values are expressed
+in milli-Watts or in an 'abstract scale'.
6.3 - Energy Model complexity