KFunc scx_bpf_pick_idle_cpu
This function picks and claims an idle CPU.
Definition
Pick and claim an idle CPU in cpus_allowed.
Idle CPU tracking may race against CPU scheduling state transitions. For example, this function may return -EBUSY as CPUs are transitioning into the idle state. If the caller then assumes that there will be dispatch events on the CPUs as they were all busy, the scheduler may end up stalling with CPUs idling while there are pending tasks. Use scx_bpf_pick_any_cpu and scx_bpf_kick_cpu to guarantee that there will be at least one dispatch event in the near future.
Unavailable if ops.update_idle() is implemented and SCX_OPS_KEEP_BUILTIN_IDLE is not set.
Parameters
cpus_allowed: Allowed cpumask
flags: SCX_PICK_IDLE_* flags
Flags
SCX_PICK_IDLE_CORE- pick a CPU whose SMT siblings are also idle
Returns
The picked idle CPU number on success. -EBUSY if no matching cpu was found.
Signature
s32 scx_bpf_pick_idle_cpu(const struct cpumask *cpus_allowed, u64 flags)
Usage
Docs could be improved
This part of the docs is incomplete, contributions are very welcome
Program types
The following program types can make use of this kfunc:
Example
Docs could be improved
This part of the docs is incomplete, contributions are very welcome