scheduler test: extd_test_scn01.3a, extd_test_scn03.2a & extd_test_scn03.3a failed on linux-linaro
Bug #1183769 reported by
Naresh Kamboju
This bug affects 1 person
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
Linaro Stable Kernel (LSK) |
Fix Released
|
Undecided
|
Unassigned | ||
Linaro big.LITTLE |
New
|
Medium
|
Robin Randhawa |
Bug Description
- A task named tasklibrary start on A7. After some time, 3 tasks per cpu are pinned on A7 (little). so global load balancer should move tasklibrary to A15, it doesn't.
- A task start tasklibrary start on A15. After some time, 3 task per cpu are pinned on A15 (BIG) so global load balancer should move tasklibrary to A7, it doesn't.
-> extd_test_scn01.3a
-> extd_test_scn03.2a
-> extd_test_scn03.3a.
The failures are due to global load balance defect where it fails to migrate busy tasks if the cores already have other tasks pinned.
extd_test_scn01.3a :
This scenario assumes the light task is already in little domain however
its computed load is increasing due to the load pattern (due to run queue
residency). The task moves to the big domain since the little domain is
oversubscribed. The runnable task get immediatly the CPU.
extd_test_scn03.2a:
This scenario assumes the heavy task is already in big
domain however its computed load is decreasing due to
the load pattern (due to idling). The task moves to the little
domain since the big domain is oversubscribed.
extd_test_scn03.3a:
This scenario assumes the light task is already in little
domain however its computed load is increasing due to
the load pattern (due to run queue residency). The task moves to big
domain because little domain is oversubscribed.