RHEL8: no_balance_cores in tuned cpu-partitioning profile may not work
Issue
The following options are set in activated cpu-partitioning tuned profile:
isolated_cores=<isolated_CPUs_list>
no_balance_cores=<isolated_CPUs_list>
If a multi-threaded task or a task with a lot of subtasks is executed in the system like this:
taskset -c <isolated_CPUs_list> ./task
or
taskset -c <all_CPUs> ./task
then all threads or childs (including the main process) are able to migrate within allowed CPUs affinity despite manual for tuned-profiles-cpu-partitioning
says:
no_balance_cores=<CPU-LIST>
List of CPUs not be considered by the kernel when doing system wide process load-balancing. Usually, this list
should be the same as isolated_cores=. This option is optional.
Environment
- Red Hat Enterprise Linux 8
- tuned
cpu-partitioning
profile is used
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