Files
linux/kernel
Andrea Righi 06efc9fe0b sched_ext: idle: Handle migration-disabled tasks in idle selection
When SCX_OPS_ENQ_MIGRATION_DISABLED is enabled, migration-disabled tasks
are also routed to ops.enqueue(). A scheduler may attempt to dispatch
such tasks directly to an idle CPU using the default idle selection
policy via scx_bpf_select_cpu_and() or scx_bpf_select_cpu_dfl().

This scenario must be properly handled by the built-in idle policy to
avoid returning an idle CPU where the target task isn't allowed to run.
Otherwise, it can lead to errors such as:

 EXIT: runtime error (SCX_DSQ_LOCAL[_ON] cannot move migration disabled Chrome_ChildIOT[291646] from CPU 3 to 14)

Prevent this by explicitly handling migration-disabled tasks in the
built-in idle selection logic, maintaining their CPU affinity.

Fixes: a730e3f7a4 ("sched_ext: idle: Consolidate default idle CPU selection kfuncs")
Signed-off-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-07-17 08:19:38 -10:00
..
2025-02-10 16:56:58 -08:00
2025-05-06 13:59:00 +02:00
2024-11-03 01:28:06 -05:00
2025-02-12 12:12:27 +01:00