KFunc scx_bpf_locked_rq
Return the run queue currently locked by SCX
Definition
Returns
Returns the run queue if a run queue lock is currently held by SCX. Otherwise emits an error and returns NULL.
Signature
struct rq *scx_bpf_locked_rq()
Note
The pointer returned by the kfunc may be NULL. Hence, it forces the user to do a NULL check on the pointer returned from the kfunc before making use of it (dereferencing or passing to another helper).
Usage
Most fields in scx_bpf_cpu_rq assume that its rq_lock is held. Furthermore they become meaningless without run queue lock, too. Make a safer version of scx_bpf_cpu_rq that only returns a run queue if we hold run queue lock of that run queue.
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