Adding upstream version 6.7.7.upstream/6.7.7

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 3 insertions, 26 deletions

diff --git a/Documentation/scheduler/sched-energy.rst b/Documentation/scheduler/sched-energy.rst
index fc853c8cc3..70e2921ef7 100644
--- a/Documentation/scheduler/sched-energy.rst
+++ b/Documentation/scheduler/sched-energy.rst
@@ -359,32 +359,9 @@ in milli-Watts or in an 'abstract scale'.
 6.3 - Energy Model complexity
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-The task wake-up path is very latency-sensitive. When the EM of a platform is
-too complex (too many CPUs, too many performance domains, too many performance
-states, ...), the cost of using it in the wake-up path can become prohibitive.
-The energy-aware wake-up algorithm has a complexity of:
-
-	C = Nd * (Nc + Ns)
-
-with: Nd the number of performance domains; Nc the number of CPUs; and Ns the
-total number of OPPs (ex: for two perf. domains with 4 OPPs each, Ns = 8).
-
-A complexity check is performed at the root domain level, when scheduling
-domains are built. EAS will not start on a root domain if its C happens to be
-higher than the completely arbitrary EM_MAX_COMPLEXITY threshold (2048 at the
-time of writing).
-
-If you really want to use EAS but the complexity of your platform's Energy
-Model is too high to be used with a single root domain, you're left with only
-two possible options:
-
-    1. split your system into separate, smaller, root domains using exclusive
-       cpusets and enable EAS locally on each of them. This option has the
-       benefit to work out of the box but the drawback of preventing load
-       balance between root domains, which can result in an unbalanced system
-       overall;
-    2. submit patches to reduce the complexity of the EAS wake-up algorithm,
-       hence enabling it to cope with larger EMs in reasonable time.
+EAS does not impose any complexity limit on the number of PDs/OPPs/CPUs but
+restricts the number of CPUs to EM_MAX_NUM_CPUS to prevent overflows during
+the energy estimation.
 
 
 6.4 - Schedutil governor