sched_ext: Relocate cpu_acquire/cpu_release to end of struct sched_ext_ops

cpu_acquire and cpu_release are deprecated and slated for removal. Move their declarations to the end of struct sched_ext_ops so an upcoming cid-form struct (sched_ext_ops_cid) can omit them entirely without disturbing the offsets of the shared fields. Switch the two SCX_HAS_OP() callers for these ops to direct field checks since the relocated ops sit outside the SCX_OPI_END range covered by the has_op bitmap. scx_kf_allow_flags[] auto-sizes to the highest used SCX_OP_IDX, so SCX_OP_IDX(cpu_release) moving to a higher index just enlarges the sparse array; the lookup logic is unchanged.

Tejun Heo committed 6 months ago

Commit 1e315c41 parent 017ec7d2 files · +34 −24Browse files

Showing the changes to kernel (2 of 2 files). Show all

Unified · Split

2 files

kernel/sched/ext.c +2 −2
kernel/sched/ext_internal.h +32 −22

kernel/sched/ext.c+2−2

@@ -2823,7 +2823,7 @@ static int balance_one(struct rq rq, struct task_struct prev) · 2822 unmodified lines
2823	2823	* core. This callback complements ->cpu_release(), which is
2824	2824	* emitted in switch_class().
2825	2825	*/
2826		− if (SCX_HAS_OP(sch, cpu_acquire))
	2826	+ if (sch->ops.cpu_acquire)
2827	2827	SCX_CALL_OP(sch, cpu_acquire, rq, cpu, NULL);
2828	2828	rq->scx.cpu_released = false;
2829	2829	}
@@ -2969,7 +2969,7 @@ static void switch_class(struct rq rq, struct task_struct next) · 139 unmodified lines
2969	2969	* next time that balance_one() is invoked.
2970	2970	*/
2971	2971	if (!rq->scx.cpu_released) {
2972		− if (SCX_HAS_OP(sch, cpu_release)) {
	2972	+ if (sch->ops.cpu_release) {
2973	2973	struct scx_cpu_release_args args = {
2974	2974	.reason = preempt_reason_from_class(next_class),
2975	2975	.task = next,

kernel/sched/ext_internal.h+32−22

@@ -529,28 +529,6 @@ struct sched_ext_ops { · 528 unmodified lines
529	529	*/
530	530	void (*update_idle)(s32 cpu, bool idle);
531	531
532		− /**
533		− * @cpu_acquire: A CPU is becoming available to the BPF scheduler
534		− * @cpu: The CPU being acquired by the BPF scheduler.
535		− * @args: Acquire arguments, see the struct definition.
536		− *
537		− * A CPU that was previously released from the BPF scheduler is now once
538		− * again under its control.
539		− */
540		− void (cpu_acquire)(s32 cpu, struct scx_cpu_acquire_args args);
541		−
542		− /**
543		− * @cpu_release: A CPU is taken away from the BPF scheduler
544		− * @cpu: The CPU being released by the BPF scheduler.
545		− * @args: Release arguments, see the struct definition.
546		− *
547		− * The specified CPU is no longer under the control of the BPF
548		− * scheduler. This could be because it was preempted by a higher
549		− * priority sched_class, though there may be other reasons as well. The
550		− * caller should consult @args->reason to determine the cause.
551		− */
552		− void (cpu_release)(s32 cpu, struct scx_cpu_release_args args);
553		−
554	532	/**
555	533	* @init_task: Initialize a task to run in a BPF scheduler
556	534	* @p: task to initialize for BPF scheduling
@@ -841,6 +819,38 @@ struct sched_ext_ops { · 284 unmodified lines
841	819
842	820	/* internal use only, must be NULL */
843	821	void __rcu *priv;
	822	+
	823	+ /*
	824	+ * Deprecated callbacks. Kept at the end of the struct so the cid-form
	825	+ * struct (sched_ext_ops_cid) can omit them without affecting the
	826	+ * shared field offsets. Use SCX_ENQ_IMMED instead. Sitting past
	827	+ * SCX_OPI_END means has_op doesn't cover them, so SCX_HAS_OP() cannot
	828	+ * be used; callers must test sch->ops.cpu_acquire / cpu_release
	829	+ * directly.
	830	+ */
	831	+
	832	+ /**
	833	+ * @cpu_acquire: A CPU is becoming available to the BPF scheduler
	834	+ * @cpu: The CPU being acquired by the BPF scheduler.
	835	+ * @args: Acquire arguments, see the struct definition.
	836	+ *
	837	+ * A CPU that was previously released from the BPF scheduler is now once
	838	+ * again under its control. Deprecated; use SCX_ENQ_IMMED instead.
	839	+ */
	840	+ void (cpu_acquire)(s32 cpu, struct scx_cpu_acquire_args args);
	841	+
	842	+ /**
	843	+ * @cpu_release: A CPU is taken away from the BPF scheduler
	844	+ * @cpu: The CPU being released by the BPF scheduler.
	845	+ * @args: Release arguments, see the struct definition.
	846	+ *
	847	+ * The specified CPU is no longer under the control of the BPF
	848	+ * scheduler. This could be because it was preempted by a higher
	849	+ * priority sched_class, though there may be other reasons as well. The
	850	+ * caller should consult @args->reason to determine the cause.
	851	+ * Deprecated; use SCX_ENQ_IMMED instead.
	852	+ */
	853	+ void (cpu_release)(s32 cpu, struct scx_cpu_release_args args);
844	854	};
845	855
846	856	enum scx_opi {