KFunc scx_bpf_dsq_insert
This function inserts a task into the First In First Out(FIFO) queue of a Dispatch Queue(DSQ)
Definition
Insert p into the FIFO queue of the DSQ identified by dsq_id. It is safe to call this function spuriously. Can be called from sched_ext_ops.enqueue, sched_ext_ops.select_cpu, and sched_ext_ops.dispatch.
When called from sched_ext_ops.select_cpu or sched_ext_ops.enqueue, it's for direct dispatch and p must match the task being enqueued.
When called from sched_ext_ops.select_cpu, enq_flags and dsp_id are stored, and p will be directly inserted into the corresponding dispatch queue after sched_ext_ops.select_cpu returns. If p is inserted into SCX_DSQ_LOCAL, it will be inserted into the local DSQ of the CPU returned by sched_ext_ops.select_cpu. enq_flags are OR'd with the enqueue flags on the enqueue path before the task is inserted.
When called from sched_ext_ops.dispatch, there are no restrictions on p or dsq_id and this function can be called up to sched_ext_ops.dispatch_max_batch times to insert multiple tasks. scx_bpf_dispatch_nr_slots returns the number of the remaining slots. scx_bpf_consume flushes the batch and resets the counter.
This function doesn't have any locking restrictions and may be called under BPF locks (in the future when BPF introduces more flexible locking).
p is allowed to run for slice. The scheduling path is triggered on slice exhaustion. If zero, the current residual slice is maintained. If SCX_SLICE_INF, p never expires and the BPF scheduler must kick the CPU with scx_bpf_kick_cpu to trigger scheduling.
Parameters
p: task_struct to insert
dsq_id: DSQ to insert into
slice: duration p can run for in nanoseconds, 0 to keep the current value
enq_flags: Bitfield of flags, see enum scx_enq_flags for valid values.
Signature
void scx_bpf_dsq_insert(struct task_struct *p, u64 dsq_id, u64 slice, u64 enq_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