Avancement analyse thread placement

migrations/migrations.org

@@ -546,14 +546,14 @@ domain2 : NUMA
 
 *** select_task_rq_fair(SD_BALANCE_WAKE) -> place close to previous CPU and waker
     + Criteria : Previous CPU and waker CPU are both part of a scheduling domain whose
-                 flag SD_WAKE_AFFINE is set.
+                 flag SD_WAKE_AFFINE is set, lowest domain first.
       Motivation : Consolidation of waker/wakee on shared cache ?
       Note : TODO Motivation not clear. The flag SD_WAKE_AFFINE is set on all domains
              on the mc2, even NUMA domains.
     + Criteria : Number of wakees is less than number of CPUs in llc domain of waker
       Motivation : Consolidation, keep waker/wakee with a close relationship together
 		   Spread wakee threads when waker:wakees relationship is 1:N.
-    + Criteria : Capacity of waking CPU fits the waking thread utilization
+    + Criteria : Capacity of waking CPU fits the waking(wakee?) thread utilization
       Motivation : Avoid consolidation on a CPU whose capacity is not good enough
                    Meant for asymmetric architectures
     + Criteria : if load of waker CPU is less than load of previous CPU, then wake up
@@ -574,3 +574,38 @@ domain2 : NUMA
       Motivation : ???
 
 ** Load Balancing
+
+*** Busiest CPU selection ASYM_PACKING
+    + Criteria : SD_ASYM_PACKING set on scheduling domain
+      Motivation :  
+*** Busiest CPU Selection
+
+*** Throttled
+    + Criteria : One of the CPU (src or dst) is throttled (frequency slowed down): Keep here
+
+*** Numa :
+    + Criteria : if task has NUMA faults : Consider cache
+    + Criteria : Src node is preferred NUMA node and runqueue
+                 has more task than task which would prefer staying : Migrate
+    + Criteria : Src node is preferred NUMA node and runqueue
+                 has less task than tasks which would prefer staying : Keep here
+    + Criteria : Dst node is preferred NUMA node : Migrate
+
+*** Cache :
+    + Criteria : Task if next or last buddy : Keep here
+      Motivation : Favor "cache-hotness"
+    + Criteria : Task last run delay is less than sched_migration_cost
+
+*** 
+
+        
+The 
+
+Once the idlest CPU has been elected to run load balancing on behalf of the scheduling domain,
+the algorithm will proceed to look for the busiest CPU. It will then check that the migration
+meets a certain set of criteria.
+
+NUMA
+
+If NUMA balancing is enabled, the scheduler keeps track of different statistics about the NUMA behavior of the machines.
+Among these statistics, it stores the number of NUMA faults  for each threads its preferred NUMA node