diff --git a/kernel/sched/build_policy.c b/kernel/sched/build_policy.c
index c4a488e..755883fa 100644
--- a/kernel/sched/build_policy.c
+++ b/kernel/sched/build_policy.c
@@ -58,6 +58,7 @@
 #include "deadline.c"
 
 #ifdef CONFIG_SCHED_CLASS_EXT
+# include "ext_internal.h"
 # include "ext.c"
 # include "ext_idle.c"
 #endif
diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index fda2b4e..7e15e85 100644
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -9,1040 +9,6 @@
 #include <linux/btf_ids.h>
 #include "ext_idle.h"
 
-#define SCX_OP_IDX(op)		(offsetof(struct sched_ext_ops, op) / sizeof(void (*)(void)))
-
-enum scx_consts {
-	SCX_DSP_DFL_MAX_BATCH		= 32,
-	SCX_DSP_MAX_LOOPS		= 32,
-	SCX_WATCHDOG_MAX_TIMEOUT	= 30 * HZ,
-
-	SCX_EXIT_BT_LEN			= 64,
-	SCX_EXIT_MSG_LEN		= 1024,
-	SCX_EXIT_DUMP_DFL_LEN		= 32768,
-
-	SCX_CPUPERF_ONE			= SCHED_CAPACITY_SCALE,
-
-	/*
-	 * Iterating all tasks may take a while. Periodically drop
-	 * scx_tasks_lock to avoid causing e.g. CSD and RCU stalls.
-	 */
-	SCX_TASK_ITER_BATCH		= 32,
-};
-
-enum scx_exit_kind {
-	SCX_EXIT_NONE,
-	SCX_EXIT_DONE,
-
-	SCX_EXIT_UNREG = 64,	/* user-space initiated unregistration */
-	SCX_EXIT_UNREG_BPF,	/* BPF-initiated unregistration */
-	SCX_EXIT_UNREG_KERN,	/* kernel-initiated unregistration */
-	SCX_EXIT_SYSRQ,		/* requested by 'S' sysrq */
-
-	SCX_EXIT_ERROR = 1024,	/* runtime error, error msg contains details */
-	SCX_EXIT_ERROR_BPF,	/* ERROR but triggered through scx_bpf_error() */
-	SCX_EXIT_ERROR_STALL,	/* watchdog detected stalled runnable tasks */
-};
-
-/*
- * An exit code can be specified when exiting with scx_bpf_exit() or scx_exit(),
- * corresponding to exit_kind UNREG_BPF and UNREG_KERN respectively. The codes
- * are 64bit of the format:
- *
- *   Bits: [63  ..  48 47   ..  32 31 .. 0]
- *         [ SYS ACT ] [ SYS RSN ] [ USR  ]
- *
- *   SYS ACT: System-defined exit actions
- *   SYS RSN: System-defined exit reasons
- *   USR    : User-defined exit codes and reasons
- *
- * Using the above, users may communicate intention and context by ORing system
- * actions and/or system reasons with a user-defined exit code.
- */
-enum scx_exit_code {
-	/* Reasons */
-	SCX_ECODE_RSN_HOTPLUG	= 1LLU << 32,
-
-	/* Actions */
-	SCX_ECODE_ACT_RESTART	= 1LLU << 48,
-};
-
-/*
- * scx_exit_info is passed to ops.exit() to describe why the BPF scheduler is
- * being disabled.
- */
-struct scx_exit_info {
-	/* %SCX_EXIT_* - broad category of the exit reason */
-	enum scx_exit_kind	kind;
-
-	/* exit code if gracefully exiting */
-	s64			exit_code;
-
-	/* textual representation of the above */
-	const char		*reason;
-
-	/* backtrace if exiting due to an error */
-	unsigned long		*bt;
-	u32			bt_len;
-
-	/* informational message */
-	char			*msg;
-
-	/* debug dump */
-	char			*dump;
-};
-
-/* sched_ext_ops.flags */
-enum scx_ops_flags {
-	/*
-	 * Keep built-in idle tracking even if ops.update_idle() is implemented.
-	 */
-	SCX_OPS_KEEP_BUILTIN_IDLE	= 1LLU << 0,
-
-	/*
-	 * By default, if there are no other task to run on the CPU, ext core
-	 * keeps running the current task even after its slice expires. If this
-	 * flag is specified, such tasks are passed to ops.enqueue() with
-	 * %SCX_ENQ_LAST. See the comment above %SCX_ENQ_LAST for more info.
-	 */
-	SCX_OPS_ENQ_LAST		= 1LLU << 1,
-
-	/*
-	 * An exiting task may schedule after PF_EXITING is set. In such cases,
-	 * bpf_task_from_pid() may not be able to find the task and if the BPF
-	 * scheduler depends on pid lookup for dispatching, the task will be
-	 * lost leading to various issues including RCU grace period stalls.
-	 *
-	 * To mask this problem, by default, unhashed tasks are automatically
-	 * dispatched to the local DSQ on enqueue. If the BPF scheduler doesn't
-	 * depend on pid lookups and wants to handle these tasks directly, the
-	 * following flag can be used.
-	 */
-	SCX_OPS_ENQ_EXITING		= 1LLU << 2,
-
-	/*
-	 * If set, only tasks with policy set to SCHED_EXT are attached to
-	 * sched_ext. If clear, SCHED_NORMAL tasks are also included.
-	 */
-	SCX_OPS_SWITCH_PARTIAL		= 1LLU << 3,
-
-	/*
-	 * A migration disabled task can only execute on its current CPU. By
-	 * default, such tasks are automatically put on the CPU's local DSQ with
-	 * the default slice on enqueue. If this ops flag is set, they also go
-	 * through ops.enqueue().
-	 *
-	 * A migration disabled task never invokes ops.select_cpu() as it can
-	 * only select the current CPU. Also, p->cpus_ptr will only contain its
-	 * current CPU while p->nr_cpus_allowed keeps tracking p->user_cpus_ptr
-	 * and thus may disagree with cpumask_weight(p->cpus_ptr).
-	 */
-	SCX_OPS_ENQ_MIGRATION_DISABLED	= 1LLU << 4,
-
-	/*
-	 * Queued wakeup (ttwu_queue) is a wakeup optimization that invokes
-	 * ops.enqueue() on the ops.select_cpu() selected or the wakee's
-	 * previous CPU via IPI (inter-processor interrupt) to reduce cacheline
-	 * transfers. When this optimization is enabled, ops.select_cpu() is
-	 * skipped in some cases (when racing against the wakee switching out).
-	 * As the BPF scheduler may depend on ops.select_cpu() being invoked
-	 * during wakeups, queued wakeup is disabled by default.
-	 *
-	 * If this ops flag is set, queued wakeup optimization is enabled and
-	 * the BPF scheduler must be able to handle ops.enqueue() invoked on the
-	 * wakee's CPU without preceding ops.select_cpu() even for tasks which
-	 * may be executed on multiple CPUs.
-	 */
-	SCX_OPS_ALLOW_QUEUED_WAKEUP	= 1LLU << 5,
-
-	/*
-	 * If set, enable per-node idle cpumasks. If clear, use a single global
-	 * flat idle cpumask.
-	 */
-	SCX_OPS_BUILTIN_IDLE_PER_NODE	= 1LLU << 6,
-
-	/*
-	 * CPU cgroup support flags
-	 */
-	SCX_OPS_HAS_CGROUP_WEIGHT	= 1LLU << 16,	/* DEPRECATED, will be removed on 6.18 */
-
-	SCX_OPS_ALL_FLAGS		= SCX_OPS_KEEP_BUILTIN_IDLE |
-					  SCX_OPS_ENQ_LAST |
-					  SCX_OPS_ENQ_EXITING |
-					  SCX_OPS_ENQ_MIGRATION_DISABLED |
-					  SCX_OPS_ALLOW_QUEUED_WAKEUP |
-					  SCX_OPS_SWITCH_PARTIAL |
-					  SCX_OPS_BUILTIN_IDLE_PER_NODE |
-					  SCX_OPS_HAS_CGROUP_WEIGHT,
-
-	/* high 8 bits are internal, don't include in SCX_OPS_ALL_FLAGS */
-	__SCX_OPS_INTERNAL_MASK		= 0xffLLU << 56,
-
-	SCX_OPS_HAS_CPU_PREEMPT		= 1LLU << 56,
-};
-
-/* argument container for ops.init_task() */
-struct scx_init_task_args {
-	/*
-	 * Set if ops.init_task() is being invoked on the fork path, as opposed
-	 * to the scheduler transition path.
-	 */
-	bool			fork;
-#ifdef CONFIG_EXT_GROUP_SCHED
-	/* the cgroup the task is joining */
-	struct cgroup		*cgroup;
-#endif
-};
-
-/* argument container for ops.exit_task() */
-struct scx_exit_task_args {
-	/* Whether the task exited before running on sched_ext. */
-	bool cancelled;
-};
-
-/* argument container for ops->cgroup_init() */
-struct scx_cgroup_init_args {
-	/* the weight of the cgroup [1..10000] */
-	u32			weight;
-
-	/* bandwidth control parameters from cpu.max and cpu.max.burst */
-	u64			bw_period_us;
-	u64			bw_quota_us;
-	u64			bw_burst_us;
-};
-
-enum scx_cpu_preempt_reason {
-	/* next task is being scheduled by &sched_class_rt */
-	SCX_CPU_PREEMPT_RT,
-	/* next task is being scheduled by &sched_class_dl */
-	SCX_CPU_PREEMPT_DL,
-	/* next task is being scheduled by &sched_class_stop */
-	SCX_CPU_PREEMPT_STOP,
-	/* unknown reason for SCX being preempted */
-	SCX_CPU_PREEMPT_UNKNOWN,
-};
-
-/*
- * Argument container for ops->cpu_acquire(). Currently empty, but may be
- * expanded in the future.
- */
-struct scx_cpu_acquire_args {};
-
-/* argument container for ops->cpu_release() */
-struct scx_cpu_release_args {
-	/* the reason the CPU was preempted */
-	enum scx_cpu_preempt_reason reason;
-
-	/* the task that's going to be scheduled on the CPU */
-	struct task_struct	*task;
-};
-
-/*
- * Informational context provided to dump operations.
- */
-struct scx_dump_ctx {
-	enum scx_exit_kind	kind;
-	s64			exit_code;
-	const char		*reason;
-	u64			at_ns;
-	u64			at_jiffies;
-};
-
-/**
- * struct sched_ext_ops - Operation table for BPF scheduler implementation
- *
- * A BPF scheduler can implement an arbitrary scheduling policy by
- * implementing and loading operations in this table. Note that a userland
- * scheduling policy can also be implemented using the BPF scheduler
- * as a shim layer.
- */
-struct sched_ext_ops {
-	/**
-	 * @select_cpu: Pick the target CPU for a task which is being woken up
-	 * @p: task being woken up
-	 * @prev_cpu: the cpu @p was on before sleeping
-	 * @wake_flags: SCX_WAKE_*
-	 *
-	 * Decision made here isn't final. @p may be moved to any CPU while it
-	 * is getting dispatched for execution later. However, as @p is not on
-	 * the rq at this point, getting the eventual execution CPU right here
-	 * saves a small bit of overhead down the line.
-	 *
-	 * If an idle CPU is returned, the CPU is kicked and will try to
-	 * dispatch. While an explicit custom mechanism can be added,
-	 * select_cpu() serves as the default way to wake up idle CPUs.
-	 *
-	 * @p may be inserted into a DSQ directly by calling
-	 * scx_bpf_dsq_insert(). If so, the ops.enqueue() will be skipped.
-	 * Directly inserting into %SCX_DSQ_LOCAL will put @p in the local DSQ
-	 * of the CPU returned by this operation.
-	 *
-	 * Note that select_cpu() is never called for tasks that can only run
-	 * on a single CPU or tasks with migration disabled, as they don't have
-	 * the option to select a different CPU. See select_task_rq() for
-	 * details.
-	 */
-	s32 (*select_cpu)(struct task_struct *p, s32 prev_cpu, u64 wake_flags);
-
-	/**
-	 * @enqueue: Enqueue a task on the BPF scheduler
-	 * @p: task being enqueued
-	 * @enq_flags: %SCX_ENQ_*
-	 *
-	 * @p is ready to run. Insert directly into a DSQ by calling
-	 * scx_bpf_dsq_insert() or enqueue on the BPF scheduler. If not directly
-	 * inserted, the bpf scheduler owns @p and if it fails to dispatch @p,
-	 * the task will stall.
-	 *
-	 * If @p was inserted into a DSQ from ops.select_cpu(), this callback is
-	 * skipped.
-	 */
-	void (*enqueue)(struct task_struct *p, u64 enq_flags);
-
-	/**
-	 * @dequeue: Remove a task from the BPF scheduler
-	 * @p: task being dequeued
-	 * @deq_flags: %SCX_DEQ_*
-	 *
-	 * Remove @p from the BPF scheduler. This is usually called to isolate
-	 * the task while updating its scheduling properties (e.g. priority).
-	 *
-	 * The ext core keeps track of whether the BPF side owns a given task or
-	 * not and can gracefully ignore spurious dispatches from BPF side,
-	 * which makes it safe to not implement this method. However, depending
-	 * on the scheduling logic, this can lead to confusing behaviors - e.g.
-	 * scheduling position not being updated across a priority change.
-	 */
-	void (*dequeue)(struct task_struct *p, u64 deq_flags);
-
-	/**
-	 * @dispatch: Dispatch tasks from the BPF scheduler and/or user DSQs
-	 * @cpu: CPU to dispatch tasks for
-	 * @prev: previous task being switched out
-	 *
-	 * Called when a CPU's local dsq is empty. The operation should dispatch
-	 * one or more tasks from the BPF scheduler into the DSQs using
-	 * scx_bpf_dsq_insert() and/or move from user DSQs into the local DSQ
-	 * using scx_bpf_dsq_move_to_local().
-	 *
-	 * The maximum number of times scx_bpf_dsq_insert() can be called
-	 * without an intervening scx_bpf_dsq_move_to_local() is specified by
-	 * ops.dispatch_max_batch. See the comments on top of the two functions
-	 * for more details.
-	 *
-	 * When not %NULL, @prev is an SCX task with its slice depleted. If
-	 * @prev is still runnable as indicated by set %SCX_TASK_QUEUED in
-	 * @prev->scx.flags, it is not enqueued yet and will be enqueued after
-	 * ops.dispatch() returns. To keep executing @prev, return without
-	 * dispatching or moving any tasks. Also see %SCX_OPS_ENQ_LAST.
-	 */
-	void (*dispatch)(s32 cpu, struct task_struct *prev);
-
-	/**
-	 * @tick: Periodic tick
-	 * @p: task running currently
-	 *
-	 * This operation is called every 1/HZ seconds on CPUs which are
-	 * executing an SCX task. Setting @p->scx.slice to 0 will trigger an
-	 * immediate dispatch cycle on the CPU.
-	 */
-	void (*tick)(struct task_struct *p);
-
-	/**
-	 * @runnable: A task is becoming runnable on its associated CPU
-	 * @p: task becoming runnable
-	 * @enq_flags: %SCX_ENQ_*
-	 *
-	 * This and the following three functions can be used to track a task's
-	 * execution state transitions. A task becomes ->runnable() on a CPU,
-	 * and then goes through one or more ->running() and ->stopping() pairs
-	 * as it runs on the CPU, and eventually becomes ->quiescent() when it's
-	 * done running on the CPU.
-	 *
-	 * @p is becoming runnable on the CPU because it's
-	 *
-	 * - waking up (%SCX_ENQ_WAKEUP)
-	 * - being moved from another CPU
-	 * - being restored after temporarily taken off the queue for an
-	 *   attribute change.
-	 *
-	 * This and ->enqueue() are related but not coupled. This operation
-	 * notifies @p's state transition and may not be followed by ->enqueue()
-	 * e.g. when @p is being dispatched to a remote CPU, or when @p is
-	 * being enqueued on a CPU experiencing a hotplug event. Likewise, a
-	 * task may be ->enqueue()'d without being preceded by this operation
-	 * e.g. after exhausting its slice.
-	 */
-	void (*runnable)(struct task_struct *p, u64 enq_flags);
-
-	/**
-	 * @running: A task is starting to run on its associated CPU
-	 * @p: task starting to run
-	 *
-	 * Note that this callback may be called from a CPU other than the
-	 * one the task is going to run on. This can happen when a task
-	 * property is changed (i.e., affinity), since scx_next_task_scx(),
-	 * which triggers this callback, may run on a CPU different from
-	 * the task's assigned CPU.
-	 *
-	 * Therefore, always use scx_bpf_task_cpu(@p) to determine the
-	 * target CPU the task is going to use.
-	 *
-	 * See ->runnable() for explanation on the task state notifiers.
-	 */
-	void (*running)(struct task_struct *p);
-
-	/**
-	 * @stopping: A task is stopping execution
-	 * @p: task stopping to run
-	 * @runnable: is task @p still runnable?
-	 *
-	 * Note that this callback may be called from a CPU other than the
-	 * one the task was running on. This can happen when a task
-	 * property is changed (i.e., affinity), since dequeue_task_scx(),
-	 * which triggers this callback, may run on a CPU different from
-	 * the task's assigned CPU.
-	 *
-	 * Therefore, always use scx_bpf_task_cpu(@p) to retrieve the CPU
-	 * the task was running on.
-	 *
-	 * See ->runnable() for explanation on the task state notifiers. If
-	 * !@runnable, ->quiescent() will be invoked after this operation
-	 * returns.
-	 */
-	void (*stopping)(struct task_struct *p, bool runnable);
-
-	/**
-	 * @quiescent: A task is becoming not runnable on its associated CPU
-	 * @p: task becoming not runnable
-	 * @deq_flags: %SCX_DEQ_*
-	 *
-	 * See ->runnable() for explanation on the task state notifiers.
-	 *
-	 * @p is becoming quiescent on the CPU because it's
-	 *
-	 * - sleeping (%SCX_DEQ_SLEEP)
-	 * - being moved to another CPU
-	 * - being temporarily taken off the queue for an attribute change
-	 *   (%SCX_DEQ_SAVE)
-	 *
-	 * This and ->dequeue() are related but not coupled. This operation
-	 * notifies @p's state transition and may not be preceded by ->dequeue()
-	 * e.g. when @p is being dispatched to a remote CPU.
-	 */
-	void (*quiescent)(struct task_struct *p, u64 deq_flags);
-
-	/**
-	 * @yield: Yield CPU
-	 * @from: yielding task
-	 * @to: optional yield target task
-	 *
-	 * If @to is NULL, @from is yielding the CPU to other runnable tasks.
-	 * The BPF scheduler should ensure that other available tasks are
-	 * dispatched before the yielding task. Return value is ignored in this
-	 * case.
-	 *
-	 * If @to is not-NULL, @from wants to yield the CPU to @to. If the bpf
-	 * scheduler can implement the request, return %true; otherwise, %false.
-	 */
-	bool (*yield)(struct task_struct *from, struct task_struct *to);
-
-	/**
-	 * @core_sched_before: Task ordering for core-sched
-	 * @a: task A
-	 * @b: task B
-	 *
-	 * Used by core-sched to determine the ordering between two tasks. See
-	 * Documentation/admin-guide/hw-vuln/core-scheduling.rst for details on
-	 * core-sched.
-	 *
-	 * Both @a and @b are runnable and may or may not currently be queued on
-	 * the BPF scheduler. Should return %true if @a should run before @b.
-	 * %false if there's no required ordering or @b should run before @a.
-	 *
-	 * If not specified, the default is ordering them according to when they
-	 * became runnable.
-	 */
-	bool (*core_sched_before)(struct task_struct *a, struct task_struct *b);
-
-	/**
-	 * @set_weight: Set task weight
-	 * @p: task to set weight for
-	 * @weight: new weight [1..10000]
-	 *
-	 * Update @p's weight to @weight.
-	 */
-	void (*set_weight)(struct task_struct *p, u32 weight);
-
-	/**
-	 * @set_cpumask: Set CPU affinity
-	 * @p: task to set CPU affinity for
-	 * @cpumask: cpumask of cpus that @p can run on
-	 *
-	 * Update @p's CPU affinity to @cpumask.
-	 */
-	void (*set_cpumask)(struct task_struct *p,
-			    const struct cpumask *cpumask);
-
-	/**
-	 * @update_idle: Update the idle state of a CPU
-	 * @cpu: CPU to update the idle state for
-	 * @idle: whether entering or exiting the idle state
-	 *
-	 * This operation is called when @rq's CPU goes or leaves the idle
-	 * state. By default, implementing this operation disables the built-in
-	 * idle CPU tracking and the following helpers become unavailable:
-	 *
-	 * - scx_bpf_select_cpu_dfl()
-	 * - scx_bpf_select_cpu_and()
-	 * - scx_bpf_test_and_clear_cpu_idle()
-	 * - scx_bpf_pick_idle_cpu()
-	 *
-	 * The user also must implement ops.select_cpu() as the default
-	 * implementation relies on scx_bpf_select_cpu_dfl().
-	 *
-	 * Specify the %SCX_OPS_KEEP_BUILTIN_IDLE flag to keep the built-in idle
-	 * tracking.
-	 */
-	void (*update_idle)(s32 cpu, bool idle);
-
-	/**
-	 * @cpu_acquire: A CPU is becoming available to the BPF scheduler
-	 * @cpu: The CPU being acquired by the BPF scheduler.
-	 * @args: Acquire arguments, see the struct definition.
-	 *
-	 * A CPU that was previously released from the BPF scheduler is now once
-	 * again under its control.
-	 */
-	void (*cpu_acquire)(s32 cpu, struct scx_cpu_acquire_args *args);
-
-	/**
-	 * @cpu_release: A CPU is taken away from the BPF scheduler
-	 * @cpu: The CPU being released by the BPF scheduler.
-	 * @args: Release arguments, see the struct definition.
-	 *
-	 * The specified CPU is no longer under the control of the BPF
-	 * scheduler. This could be because it was preempted by a higher
-	 * priority sched_class, though there may be other reasons as well. The
-	 * caller should consult @args->reason to determine the cause.
-	 */
-	void (*cpu_release)(s32 cpu, struct scx_cpu_release_args *args);
-
-	/**
-	 * @init_task: Initialize a task to run in a BPF scheduler
-	 * @p: task to initialize for BPF scheduling
-	 * @args: init arguments, see the struct definition
-	 *
-	 * Either we're loading a BPF scheduler or a new task is being forked.
-	 * Initialize @p for BPF scheduling. This operation may block and can
-	 * be used for allocations, and is called exactly once for a task.
-	 *
-	 * Return 0 for success, -errno for failure. An error return while
-	 * loading will abort loading of the BPF scheduler. During a fork, it
-	 * will abort that specific fork.
-	 */
-	s32 (*init_task)(struct task_struct *p, struct scx_init_task_args *args);
-
-	/**
-	 * @exit_task: Exit a previously-running task from the system
-	 * @p: task to exit
-	 * @args: exit arguments, see the struct definition
-	 *
-	 * @p is exiting or the BPF scheduler is being unloaded. Perform any
-	 * necessary cleanup for @p.
-	 */
-	void (*exit_task)(struct task_struct *p, struct scx_exit_task_args *args);
-
-	/**
-	 * @enable: Enable BPF scheduling for a task
-	 * @p: task to enable BPF scheduling for
-	 *
-	 * Enable @p for BPF scheduling. enable() is called on @p any time it
-	 * enters SCX, and is always paired with a matching disable().
-	 */
-	void (*enable)(struct task_struct *p);
-
-	/**
-	 * @disable: Disable BPF scheduling for a task
-	 * @p: task to disable BPF scheduling for
-	 *
-	 * @p is exiting, leaving SCX or the BPF scheduler is being unloaded.
-	 * Disable BPF scheduling for @p. A disable() call is always matched
-	 * with a prior enable() call.
-	 */
-	void (*disable)(struct task_struct *p);
-
-	/**
-	 * @dump: Dump BPF scheduler state on error
-	 * @ctx: debug dump context
-	 *
-	 * Use scx_bpf_dump() to generate BPF scheduler specific debug dump.
-	 */
-	void (*dump)(struct scx_dump_ctx *ctx);
-
-	/**
-	 * @dump_cpu: Dump BPF scheduler state for a CPU on error
-	 * @ctx: debug dump context
-	 * @cpu: CPU to generate debug dump for
-	 * @idle: @cpu is currently idle without any runnable tasks
-	 *
-	 * Use scx_bpf_dump() to generate BPF scheduler specific debug dump for
-	 * @cpu. If @idle is %true and this operation doesn't produce any
-	 * output, @cpu is skipped for dump.
-	 */
-	void (*dump_cpu)(struct scx_dump_ctx *ctx, s32 cpu, bool idle);
-
-	/**
-	 * @dump_task: Dump BPF scheduler state for a runnable task on error
-	 * @ctx: debug dump context
-	 * @p: runnable task to generate debug dump for
-	 *
-	 * Use scx_bpf_dump() to generate BPF scheduler specific debug dump for
-	 * @p.
-	 */
-	void (*dump_task)(struct scx_dump_ctx *ctx, struct task_struct *p);
-
-#ifdef CONFIG_EXT_GROUP_SCHED
-	/**
-	 * @cgroup_init: Initialize a cgroup
-	 * @cgrp: cgroup being initialized
-	 * @args: init arguments, see the struct definition
-	 *
-	 * Either the BPF scheduler is being loaded or @cgrp created, initialize
-	 * @cgrp for sched_ext. This operation may block.
-	 *
-	 * Return 0 for success, -errno for failure. An error return while
-	 * loading will abort loading of the BPF scheduler. During cgroup
-	 * creation, it will abort the specific cgroup creation.
-	 */
-	s32 (*cgroup_init)(struct cgroup *cgrp,
-			   struct scx_cgroup_init_args *args);
-
-	/**
-	 * @cgroup_exit: Exit a cgroup
-	 * @cgrp: cgroup being exited
-	 *
-	 * Either the BPF scheduler is being unloaded or @cgrp destroyed, exit
-	 * @cgrp for sched_ext. This operation my block.
-	 */
-	void (*cgroup_exit)(struct cgroup *cgrp);
-
-	/**
-	 * @cgroup_prep_move: Prepare a task to be moved to a different cgroup
-	 * @p: task being moved
-	 * @from: cgroup @p is being moved from
-	 * @to: cgroup @p is being moved to
-	 *
-	 * Prepare @p for move from cgroup @from to @to. This operation may
-	 * block and can be used for allocations.
-	 *
-	 * Return 0 for success, -errno for failure. An error return aborts the
-	 * migration.
-	 */
-	s32 (*cgroup_prep_move)(struct task_struct *p,
-				struct cgroup *from, struct cgroup *to);
-
-	/**
-	 * @cgroup_move: Commit cgroup move
-	 * @p: task being moved
-	 * @from: cgroup @p is being moved from
-	 * @to: cgroup @p is being moved to
-	 *
-	 * Commit the move. @p is dequeued during this operation.
-	 */
-	void (*cgroup_move)(struct task_struct *p,
-			    struct cgroup *from, struct cgroup *to);
-
-	/**
-	 * @cgroup_cancel_move: Cancel cgroup move
-	 * @p: task whose cgroup move is being canceled
-	 * @from: cgroup @p was being moved from
-	 * @to: cgroup @p was being moved to
-	 *
-	 * @p was cgroup_prep_move()'d but failed before reaching cgroup_move().
-	 * Undo the preparation.
-	 */
-	void (*cgroup_cancel_move)(struct task_struct *p,
-				   struct cgroup *from, struct cgroup *to);
-
-	/**
-	 * @cgroup_set_weight: A cgroup's weight is being changed
-	 * @cgrp: cgroup whose weight is being updated
-	 * @weight: new weight [1..10000]
-	 *
-	 * Update @cgrp's weight to @weight.
-	 */
-	void (*cgroup_set_weight)(struct cgroup *cgrp, u32 weight);
-
-	/**
-	 * @cgroup_set_bandwidth: A cgroup's bandwidth is being changed
-	 * @cgrp: cgroup whose bandwidth is being updated
-	 * @period_us: bandwidth control period
-	 * @quota_us: bandwidth control quota
-	 * @burst_us: bandwidth control burst
-	 *
-	 * Update @cgrp's bandwidth control parameters. This is from the cpu.max
-	 * cgroup interface.
-	 *
-	 * @quota_us / @period_us determines the CPU bandwidth @cgrp is entitled
-	 * to. For example, if @period_us is 1_000_000 and @quota_us is
-	 * 2_500_000. @cgrp is entitled to 2.5 CPUs. @burst_us can be
-	 * interpreted in the same fashion and specifies how much @cgrp can
-	 * burst temporarily. The specific control mechanism and thus the
-	 * interpretation of @period_us and burstiness is upto to the BPF
-	 * scheduler.
-	 */
-	void (*cgroup_set_bandwidth)(struct cgroup *cgrp,
-				     u64 period_us, u64 quota_us, u64 burst_us);
-
-#endif	/* CONFIG_EXT_GROUP_SCHED */
-
-	/*
-	 * All online ops must come before ops.cpu_online().
-	 */
-
-	/**
-	 * @cpu_online: A CPU became online
-	 * @cpu: CPU which just came up
-	 *
-	 * @cpu just came online. @cpu will not call ops.enqueue() or
-	 * ops.dispatch(), nor run tasks associated with other CPUs beforehand.
-	 */
-	void (*cpu_online)(s32 cpu);
-
-	/**
-	 * @cpu_offline: A CPU is going offline
-	 * @cpu: CPU which is going offline
-	 *
-	 * @cpu is going offline. @cpu will not call ops.enqueue() or
-	 * ops.dispatch(), nor run tasks associated with other CPUs afterwards.
-	 */
-	void (*cpu_offline)(s32 cpu);
-
-	/*
-	 * All CPU hotplug ops must come before ops.init().
-	 */
-
-	/**
-	 * @init: Initialize the BPF scheduler
-	 */
-	s32 (*init)(void);
-
-	/**
-	 * @exit: Clean up after the BPF scheduler
-	 * @info: Exit info
-	 *
-	 * ops.exit() is also called on ops.init() failure, which is a bit
-	 * unusual. This is to allow rich reporting through @info on how
-	 * ops.init() failed.
-	 */
-	void (*exit)(struct scx_exit_info *info);
-
-	/**
-	 * @dispatch_max_batch: Max nr of tasks that dispatch() can dispatch
-	 */
-	u32 dispatch_max_batch;
-
-	/**
-	 * @flags: %SCX_OPS_* flags
-	 */
-	u64 flags;
-
-	/**
-	 * @timeout_ms: The maximum amount of time, in milliseconds, that a
-	 * runnable task should be able to wait before being scheduled. The
-	 * maximum timeout may not exceed the default timeout of 30 seconds.
-	 *
-	 * Defaults to the maximum allowed timeout value of 30 seconds.
-	 */
-	u32 timeout_ms;
-
-	/**
-	 * @exit_dump_len: scx_exit_info.dump buffer length. If 0, the default
-	 * value of 32768 is used.
-	 */
-	u32 exit_dump_len;
-
-	/**
-	 * @hotplug_seq: A sequence number that may be set by the scheduler to
-	 * detect when a hotplug event has occurred during the loading process.
-	 * If 0, no detection occurs. Otherwise, the scheduler will fail to
-	 * load if the sequence number does not match @scx_hotplug_seq on the
-	 * enable path.
-	 */
-	u64 hotplug_seq;
-
-	/**
-	 * @name: BPF scheduler's name
-	 *
-	 * Must be a non-zero valid BPF object name including only isalnum(),
-	 * '_' and '.' chars. Shows up in kernel.sched_ext_ops sysctl while the
-	 * BPF scheduler is enabled.
-	 */
-	char name[SCX_OPS_NAME_LEN];
-
-	/* internal use only, must be NULL */
-	void *priv;
-};
-
-enum scx_opi {
-	SCX_OPI_BEGIN			= 0,
-	SCX_OPI_NORMAL_BEGIN		= 0,
-	SCX_OPI_NORMAL_END		= SCX_OP_IDX(cpu_online),
-	SCX_OPI_CPU_HOTPLUG_BEGIN	= SCX_OP_IDX(cpu_online),
-	SCX_OPI_CPU_HOTPLUG_END		= SCX_OP_IDX(init),
-	SCX_OPI_END			= SCX_OP_IDX(init),
-};
-
-/*
- * Collection of event counters. Event types are placed in descending order.
- */
-struct scx_event_stats {
-	/*
-	 * If ops.select_cpu() returns a CPU which can't be used by the task,
-	 * the core scheduler code silently picks a fallback CPU.
-	 */
-	s64		SCX_EV_SELECT_CPU_FALLBACK;
-
-	/*
-	 * When dispatching to a local DSQ, the CPU may have gone offline in
-	 * the meantime. In this case, the task is bounced to the global DSQ.
-	 */
-	s64		SCX_EV_DISPATCH_LOCAL_DSQ_OFFLINE;
-
-	/*
-	 * If SCX_OPS_ENQ_LAST is not set, the number of times that a task
-	 * continued to run because there were no other tasks on the CPU.
-	 */
-	s64		SCX_EV_DISPATCH_KEEP_LAST;
-
-	/*
-	 * If SCX_OPS_ENQ_EXITING is not set, the number of times that a task
-	 * is dispatched to a local DSQ when exiting.
-	 */
-	s64		SCX_EV_ENQ_SKIP_EXITING;
-
-	/*
-	 * If SCX_OPS_ENQ_MIGRATION_DISABLED is not set, the number of times a
-	 * migration disabled task skips ops.enqueue() and is dispatched to its
-	 * local DSQ.
-	 */
-	s64		SCX_EV_ENQ_SKIP_MIGRATION_DISABLED;
-
-	/*
-	 * Total number of times a task's time slice was refilled with the
-	 * default value (SCX_SLICE_DFL).
-	 */
-	s64		SCX_EV_REFILL_SLICE_DFL;
-
-	/*
-	 * The total duration of bypass modes in nanoseconds.
-	 */
-	s64		SCX_EV_BYPASS_DURATION;
-
-	/*
-	 * The number of tasks dispatched in the bypassing mode.
-	 */
-	s64		SCX_EV_BYPASS_DISPATCH;
-
-	/*
-	 * The number of times the bypassing mode has been activated.
-	 */
-	s64		SCX_EV_BYPASS_ACTIVATE;
-};
-
-struct scx_sched {
-	struct sched_ext_ops	ops;
-	DECLARE_BITMAP(has_op, SCX_OPI_END);
-
-	/*
-	 * Dispatch queues.
-	 *
-	 * The global DSQ (%SCX_DSQ_GLOBAL) is split per-node for scalability.
-	 * This is to avoid live-locking in bypass mode where all tasks are
-	 * dispatched to %SCX_DSQ_GLOBAL and all CPUs consume from it. If
-	 * per-node split isn't sufficient, it can be further split.
-	 */
-	struct rhashtable	dsq_hash;
-	struct scx_dispatch_q	**global_dsqs;
-
-	/*
-	 * The event counters are in a per-CPU variable to minimize the
-	 * accounting overhead. A system-wide view on the event counter is
-	 * constructed when requested by scx_bpf_events().
-	 */
-	struct scx_event_stats __percpu *event_stats_cpu;
-
-	bool			warned_zero_slice;
-
-	atomic_t		exit_kind;
-	struct scx_exit_info	*exit_info;
-
-	struct kobject		kobj;
-
-	struct kthread_worker	*helper;
-	struct irq_work		error_irq_work;
-	struct kthread_work	disable_work;
-	struct rcu_work		rcu_work;
-};
-
-enum scx_wake_flags {
-	/* expose select WF_* flags as enums */
-	SCX_WAKE_FORK		= WF_FORK,
-	SCX_WAKE_TTWU		= WF_TTWU,
-	SCX_WAKE_SYNC		= WF_SYNC,
-};
-
-enum scx_enq_flags {
-	/* expose select ENQUEUE_* flags as enums */
-	SCX_ENQ_WAKEUP		= ENQUEUE_WAKEUP,
-	SCX_ENQ_HEAD		= ENQUEUE_HEAD,
-	SCX_ENQ_CPU_SELECTED	= ENQUEUE_RQ_SELECTED,
-
-	/* high 32bits are SCX specific */
-
-	/*
-	 * Set the following to trigger preemption when calling
-	 * scx_bpf_dsq_insert() with a local dsq as the target. The slice of the
-	 * current task is cleared to zero and the CPU is kicked into the
-	 * scheduling path. Implies %SCX_ENQ_HEAD.
-	 */
-	SCX_ENQ_PREEMPT		= 1LLU << 32,
-
-	/*
-	 * The task being enqueued was previously enqueued on the current CPU's
-	 * %SCX_DSQ_LOCAL, but was removed from it in a call to the
-	 * scx_bpf_reenqueue_local() kfunc. If scx_bpf_reenqueue_local() was
-	 * invoked in a ->cpu_release() callback, and the task is again
-	 * dispatched back to %SCX_LOCAL_DSQ by this current ->enqueue(), the
-	 * task will not be scheduled on the CPU until at least the next invocation
-	 * of the ->cpu_acquire() callback.
-	 */
-	SCX_ENQ_REENQ		= 1LLU << 40,
-
-	/*
-	 * The task being enqueued is the only task available for the cpu. By
-	 * default, ext core keeps executing such tasks but when
-	 * %SCX_OPS_ENQ_LAST is specified, they're ops.enqueue()'d with the
-	 * %SCX_ENQ_LAST flag set.
-	 *
-	 * The BPF scheduler is responsible for triggering a follow-up
-	 * scheduling event. Otherwise, Execution may stall.
-	 */
-	SCX_ENQ_LAST		= 1LLU << 41,
-
-	/* high 8 bits are internal */
-	__SCX_ENQ_INTERNAL_MASK	= 0xffLLU << 56,
-
-	SCX_ENQ_CLEAR_OPSS	= 1LLU << 56,
-	SCX_ENQ_DSQ_PRIQ	= 1LLU << 57,
-};
-
-enum scx_deq_flags {
-	/* expose select DEQUEUE_* flags as enums */
-	SCX_DEQ_SLEEP		= DEQUEUE_SLEEP,
-
-	/* high 32bits are SCX specific */
-
-	/*
-	 * The generic core-sched layer decided to execute the task even though
-	 * it hasn't been dispatched yet. Dequeue from the BPF side.
-	 */
-	SCX_DEQ_CORE_SCHED_EXEC	= 1LLU << 32,
-};
-
-enum scx_pick_idle_cpu_flags {
-	SCX_PICK_IDLE_CORE	= 1LLU << 0,	/* pick a CPU whose SMT siblings are also idle */
-	SCX_PICK_IDLE_IN_NODE	= 1LLU << 1,	/* pick a CPU in the same target NUMA node */
-};
-
-enum scx_kick_flags {
-	/*
-	 * Kick the target CPU if idle. Guarantees that the target CPU goes
-	 * through at least one full scheduling cycle before going idle. If the
-	 * target CPU can be determined to be currently not idle and going to go
-	 * through a scheduling cycle before going idle, noop.
-	 */
-	SCX_KICK_IDLE		= 1LLU << 0,
-
-	/*
-	 * Preempt the current task and execute the dispatch path. If the
-	 * current task of the target CPU is an SCX task, its ->scx.slice is
-	 * cleared to zero before the scheduling path is invoked so that the
-	 * task expires and the dispatch path is invoked.
-	 */
-	SCX_KICK_PREEMPT	= 1LLU << 1,
-
-	/*
-	 * Wait for the CPU to be rescheduled. The scx_bpf_kick_cpu() call will
-	 * return after the target CPU finishes picking the next task.
-	 */
-	SCX_KICK_WAIT		= 1LLU << 2,
-};
-
-enum scx_tg_flags {
-	SCX_TG_ONLINE		= 1U << 0,
-	SCX_TG_INITED		= 1U << 1,
-};
-
-enum scx_enable_state {
-	SCX_ENABLING,
-	SCX_ENABLED,
-	SCX_DISABLING,
-	SCX_DISABLED,
-};
-
-static const char *scx_enable_state_str[] = {
-	[SCX_ENABLING]		= "enabling",
-	[SCX_ENABLED]		= "enabled",
-	[SCX_DISABLING]		= "disabling",
-	[SCX_DISABLED]		= "disabled",
-};
-
-/*
- * sched_ext_entity->ops_state
- *
- * Used to track the task ownership between the SCX core and the BPF scheduler.
- * State transitions look as follows:
- *
- * NONE -> QUEUEING -> QUEUED -> DISPATCHING
- *   ^              |                 |
- *   |              v                 v
- *   \-------------------------------/
- *
- * QUEUEING and DISPATCHING states can be waited upon. See wait_ops_state() call
- * sites for explanations on the conditions being waited upon and why they are
- * safe. Transitions out of them into NONE or QUEUED must store_release and the
- * waiters should load_acquire.
- *
- * Tracking scx_ops_state enables sched_ext core to reliably determine whether
- * any given task can be dispatched by the BPF scheduler at all times and thus
- * relaxes the requirements on the BPF scheduler. This allows the BPF scheduler
- * to try to dispatch any task anytime regardless of its state as the SCX core
- * can safely reject invalid dispatches.
- */
-enum scx_ops_state {
-	SCX_OPSS_NONE,		/* owned by the SCX core */
-	SCX_OPSS_QUEUEING,	/* in transit to the BPF scheduler */
-	SCX_OPSS_QUEUED,	/* owned by the BPF scheduler */
-	SCX_OPSS_DISPATCHING,	/* in transit back to the SCX core */
-
-	/*
-	 * QSEQ brands each QUEUED instance so that, when dispatch races
-	 * dequeue/requeue, the dispatcher can tell whether it still has a claim
-	 * on the task being dispatched.
-	 *
-	 * As some 32bit archs can't do 64bit store_release/load_acquire,
-	 * p->scx.ops_state is atomic_long_t which leaves 30 bits for QSEQ on
-	 * 32bit machines. The dispatch race window QSEQ protects is very narrow
-	 * and runs with IRQ disabled. 30 bits should be sufficient.
-	 */
-	SCX_OPSS_QSEQ_SHIFT	= 2,
-};
-
-/* Use macros to ensure that the type is unsigned long for the masks */
-#define SCX_OPSS_STATE_MASK	((1LU << SCX_OPSS_QSEQ_SHIFT) - 1)
-#define SCX_OPSS_QSEQ_MASK	(~SCX_OPSS_STATE_MASK)
-
 /*
  * NOTE: sched_ext is in the process of growing multiple scheduler support and
  * scx_root usage is in a transitional state. Naked dereferences are safe if the
diff --git a/kernel/sched/ext.h b/kernel/sched/ext.h
index 292bb41..3385860 100644
--- a/kernel/sched/ext.h
+++ b/kernel/sched/ext.h
@@ -8,29 +8,6 @@
  */
 #ifdef CONFIG_SCHED_CLASS_EXT
 
-static inline bool scx_kf_allowed_if_unlocked(void)
-{
-	return !current->scx.kf_mask;
-}
-
-static inline bool scx_rq_bypassing(struct rq *rq)
-{
-	return unlikely(rq->scx.flags & SCX_RQ_BYPASSING);
-}
-
-DECLARE_STATIC_KEY_FALSE(scx_ops_allow_queued_wakeup);
-
-DECLARE_PER_CPU(struct rq *, scx_locked_rq_state);
-
-/*
- * Return the rq currently locked from an scx callback, or NULL if no rq is
- * locked.
- */
-static inline struct rq *scx_locked_rq(void)
-{
-	return __this_cpu_read(scx_locked_rq_state);
-}
-
 void scx_tick(struct rq *rq);
 void init_scx_entity(struct sched_ext_entity *scx);
 void scx_pre_fork(struct task_struct *p);
diff --git a/kernel/sched/ext_internal.h b/kernel/sched/ext_internal.h
new file mode 100644
index 0000000..76690ed
--- /dev/null
+++ b/kernel/sched/ext_internal.h
@@ -0,0 +1,1061 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * BPF extensible scheduler class: Documentation/scheduler/sched-ext.rst
+ *
+ * Copyright (c) 2025 Meta Platforms, Inc. and affiliates.
+ * Copyright (c) 2025 Tejun Heo <tj@kernel.org>
+ */
+#define SCX_OP_IDX(op)		(offsetof(struct sched_ext_ops, op) / sizeof(void (*)(void)))
+
+enum scx_consts {
+	SCX_DSP_DFL_MAX_BATCH		= 32,
+	SCX_DSP_MAX_LOOPS		= 32,
+	SCX_WATCHDOG_MAX_TIMEOUT	= 30 * HZ,
+
+	SCX_EXIT_BT_LEN			= 64,
+	SCX_EXIT_MSG_LEN		= 1024,
+	SCX_EXIT_DUMP_DFL_LEN		= 32768,
+
+	SCX_CPUPERF_ONE			= SCHED_CAPACITY_SCALE,
+
+	/*
+	 * Iterating all tasks may take a while. Periodically drop
+	 * scx_tasks_lock to avoid causing e.g. CSD and RCU stalls.
+	 */
+	SCX_TASK_ITER_BATCH		= 32,
+};
+
+enum scx_exit_kind {
+	SCX_EXIT_NONE,
+	SCX_EXIT_DONE,
+
+	SCX_EXIT_UNREG = 64,	/* user-space initiated unregistration */
+	SCX_EXIT_UNREG_BPF,	/* BPF-initiated unregistration */
+	SCX_EXIT_UNREG_KERN,	/* kernel-initiated unregistration */
+	SCX_EXIT_SYSRQ,		/* requested by 'S' sysrq */
+
+	SCX_EXIT_ERROR = 1024,	/* runtime error, error msg contains details */
+	SCX_EXIT_ERROR_BPF,	/* ERROR but triggered through scx_bpf_error() */
+	SCX_EXIT_ERROR_STALL,	/* watchdog detected stalled runnable tasks */
+};
+
+/*
+ * An exit code can be specified when exiting with scx_bpf_exit() or scx_exit(),
+ * corresponding to exit_kind UNREG_BPF and UNREG_KERN respectively. The codes
+ * are 64bit of the format:
+ *
+ *   Bits: [63  ..  48 47   ..  32 31 .. 0]
+ *         [ SYS ACT ] [ SYS RSN ] [ USR  ]
+ *
+ *   SYS ACT: System-defined exit actions
+ *   SYS RSN: System-defined exit reasons
+ *   USR    : User-defined exit codes and reasons
+ *
+ * Using the above, users may communicate intention and context by ORing system
+ * actions and/or system reasons with a user-defined exit code.
+ */
+enum scx_exit_code {
+	/* Reasons */
+	SCX_ECODE_RSN_HOTPLUG	= 1LLU << 32,
+
+	/* Actions */
+	SCX_ECODE_ACT_RESTART	= 1LLU << 48,
+};
+
+/*
+ * scx_exit_info is passed to ops.exit() to describe why the BPF scheduler is
+ * being disabled.
+ */
+struct scx_exit_info {
+	/* %SCX_EXIT_* - broad category of the exit reason */
+	enum scx_exit_kind	kind;
+
+	/* exit code if gracefully exiting */
+	s64			exit_code;
+
+	/* textual representation of the above */
+	const char		*reason;
+
+	/* backtrace if exiting due to an error */
+	unsigned long		*bt;
+	u32			bt_len;
+
+	/* informational message */
+	char			*msg;
+
+	/* debug dump */
+	char			*dump;
+};
+
+/* sched_ext_ops.flags */
+enum scx_ops_flags {
+	/*
+	 * Keep built-in idle tracking even if ops.update_idle() is implemented.
+	 */
+	SCX_OPS_KEEP_BUILTIN_IDLE	= 1LLU << 0,
+
+	/*
+	 * By default, if there are no other task to run on the CPU, ext core
+	 * keeps running the current task even after its slice expires. If this
+	 * flag is specified, such tasks are passed to ops.enqueue() with
+	 * %SCX_ENQ_LAST. See the comment above %SCX_ENQ_LAST for more info.
+	 */
+	SCX_OPS_ENQ_LAST		= 1LLU << 1,
+
+	/*
+	 * An exiting task may schedule after PF_EXITING is set. In such cases,
+	 * bpf_task_from_pid() may not be able to find the task and if the BPF
+	 * scheduler depends on pid lookup for dispatching, the task will be
+	 * lost leading to various issues including RCU grace period stalls.
+	 *
+	 * To mask this problem, by default, unhashed tasks are automatically
+	 * dispatched to the local DSQ on enqueue. If the BPF scheduler doesn't
+	 * depend on pid lookups and wants to handle these tasks directly, the
+	 * following flag can be used.
+	 */
+	SCX_OPS_ENQ_EXITING		= 1LLU << 2,
+
+	/*
+	 * If set, only tasks with policy set to SCHED_EXT are attached to
+	 * sched_ext. If clear, SCHED_NORMAL tasks are also included.
+	 */
+	SCX_OPS_SWITCH_PARTIAL		= 1LLU << 3,
+
+	/*
+	 * A migration disabled task can only execute on its current CPU. By
+	 * default, such tasks are automatically put on the CPU's local DSQ with
+	 * the default slice on enqueue. If this ops flag is set, they also go
+	 * through ops.enqueue().
+	 *
+	 * A migration disabled task never invokes ops.select_cpu() as it can
+	 * only select the current CPU. Also, p->cpus_ptr will only contain its
+	 * current CPU while p->nr_cpus_allowed keeps tracking p->user_cpus_ptr
+	 * and thus may disagree with cpumask_weight(p->cpus_ptr).
+	 */
+	SCX_OPS_ENQ_MIGRATION_DISABLED	= 1LLU << 4,
+
+	/*
+	 * Queued wakeup (ttwu_queue) is a wakeup optimization that invokes
+	 * ops.enqueue() on the ops.select_cpu() selected or the wakee's
+	 * previous CPU via IPI (inter-processor interrupt) to reduce cacheline
+	 * transfers. When this optimization is enabled, ops.select_cpu() is
+	 * skipped in some cases (when racing against the wakee switching out).
+	 * As the BPF scheduler may depend on ops.select_cpu() being invoked
+	 * during wakeups, queued wakeup is disabled by default.
+	 *
+	 * If this ops flag is set, queued wakeup optimization is enabled and
+	 * the BPF scheduler must be able to handle ops.enqueue() invoked on the
+	 * wakee's CPU without preceding ops.select_cpu() even for tasks which
+	 * may be executed on multiple CPUs.
+	 */
+	SCX_OPS_ALLOW_QUEUED_WAKEUP	= 1LLU << 5,
+
+	/*
+	 * If set, enable per-node idle cpumasks. If clear, use a single global
+	 * flat idle cpumask.
+	 */
+	SCX_OPS_BUILTIN_IDLE_PER_NODE	= 1LLU << 6,
+
+	/*
+	 * CPU cgroup support flags
+	 */
+	SCX_OPS_HAS_CGROUP_WEIGHT	= 1LLU << 16,	/* DEPRECATED, will be removed on 6.18 */
+
+	SCX_OPS_ALL_FLAGS		= SCX_OPS_KEEP_BUILTIN_IDLE |
+					  SCX_OPS_ENQ_LAST |
+					  SCX_OPS_ENQ_EXITING |
+					  SCX_OPS_ENQ_MIGRATION_DISABLED |
+					  SCX_OPS_ALLOW_QUEUED_WAKEUP |
+					  SCX_OPS_SWITCH_PARTIAL |
+					  SCX_OPS_BUILTIN_IDLE_PER_NODE |
+					  SCX_OPS_HAS_CGROUP_WEIGHT,
+
+	/* high 8 bits are internal, don't include in SCX_OPS_ALL_FLAGS */
+	__SCX_OPS_INTERNAL_MASK		= 0xffLLU << 56,
+
+	SCX_OPS_HAS_CPU_PREEMPT		= 1LLU << 56,
+};
+
+/* argument container for ops.init_task() */
+struct scx_init_task_args {
+	/*
+	 * Set if ops.init_task() is being invoked on the fork path, as opposed
+	 * to the scheduler transition path.
+	 */
+	bool			fork;
+#ifdef CONFIG_EXT_GROUP_SCHED
+	/* the cgroup the task is joining */
+	struct cgroup		*cgroup;
+#endif
+};
+
+/* argument container for ops.exit_task() */
+struct scx_exit_task_args {
+	/* Whether the task exited before running on sched_ext. */
+	bool cancelled;
+};
+
+/* argument container for ops->cgroup_init() */
+struct scx_cgroup_init_args {
+	/* the weight of the cgroup [1..10000] */
+	u32			weight;
+
+	/* bandwidth control parameters from cpu.max and cpu.max.burst */
+	u64			bw_period_us;
+	u64			bw_quota_us;
+	u64			bw_burst_us;
+};
+
+enum scx_cpu_preempt_reason {
+	/* next task is being scheduled by &sched_class_rt */
+	SCX_CPU_PREEMPT_RT,
+	/* next task is being scheduled by &sched_class_dl */
+	SCX_CPU_PREEMPT_DL,
+	/* next task is being scheduled by &sched_class_stop */
+	SCX_CPU_PREEMPT_STOP,
+	/* unknown reason for SCX being preempted */
+	SCX_CPU_PREEMPT_UNKNOWN,
+};
+
+/*
+ * Argument container for ops->cpu_acquire(). Currently empty, but may be
+ * expanded in the future.
+ */
+struct scx_cpu_acquire_args {};
+
+/* argument container for ops->cpu_release() */
+struct scx_cpu_release_args {
+	/* the reason the CPU was preempted */
+	enum scx_cpu_preempt_reason reason;
+
+	/* the task that's going to be scheduled on the CPU */
+	struct task_struct	*task;
+};
+
+/*
+ * Informational context provided to dump operations.
+ */
+struct scx_dump_ctx {
+	enum scx_exit_kind	kind;
+	s64			exit_code;
+	const char		*reason;
+	u64			at_ns;
+	u64			at_jiffies;
+};
+
+/**
+ * struct sched_ext_ops - Operation table for BPF scheduler implementation
+ *
+ * A BPF scheduler can implement an arbitrary scheduling policy by
+ * implementing and loading operations in this table. Note that a userland
+ * scheduling policy can also be implemented using the BPF scheduler
+ * as a shim layer.
+ */
+struct sched_ext_ops {
+	/**
+	 * @select_cpu: Pick the target CPU for a task which is being woken up
+	 * @p: task being woken up
+	 * @prev_cpu: the cpu @p was on before sleeping
+	 * @wake_flags: SCX_WAKE_*
+	 *
+	 * Decision made here isn't final. @p may be moved to any CPU while it
+	 * is getting dispatched for execution later. However, as @p is not on
+	 * the rq at this point, getting the eventual execution CPU right here
+	 * saves a small bit of overhead down the line.
+	 *
+	 * If an idle CPU is returned, the CPU is kicked and will try to
+	 * dispatch. While an explicit custom mechanism can be added,
+	 * select_cpu() serves as the default way to wake up idle CPUs.
+	 *
+	 * @p may be inserted into a DSQ directly by calling
+	 * scx_bpf_dsq_insert(). If so, the ops.enqueue() will be skipped.
+	 * Directly inserting into %SCX_DSQ_LOCAL will put @p in the local DSQ
+	 * of the CPU returned by this operation.
+	 *
+	 * Note that select_cpu() is never called for tasks that can only run
+	 * on a single CPU or tasks with migration disabled, as they don't have
+	 * the option to select a different CPU. See select_task_rq() for
+	 * details.
+	 */
+	s32 (*select_cpu)(struct task_struct *p, s32 prev_cpu, u64 wake_flags);
+
+	/**
+	 * @enqueue: Enqueue a task on the BPF scheduler
+	 * @p: task being enqueued
+	 * @enq_flags: %SCX_ENQ_*
+	 *
+	 * @p is ready to run. Insert directly into a DSQ by calling
+	 * scx_bpf_dsq_insert() or enqueue on the BPF scheduler. If not directly
+	 * inserted, the bpf scheduler owns @p and if it fails to dispatch @p,
+	 * the task will stall.
+	 *
+	 * If @p was inserted into a DSQ from ops.select_cpu(), this callback is
+	 * skipped.
+	 */
+	void (*enqueue)(struct task_struct *p, u64 enq_flags);
+
+	/**
+	 * @dequeue: Remove a task from the BPF scheduler
+	 * @p: task being dequeued
+	 * @deq_flags: %SCX_DEQ_*
+	 *
+	 * Remove @p from the BPF scheduler. This is usually called to isolate
+	 * the task while updating its scheduling properties (e.g. priority).
+	 *
+	 * The ext core keeps track of whether the BPF side owns a given task or
+	 * not and can gracefully ignore spurious dispatches from BPF side,
+	 * which makes it safe to not implement this method. However, depending
+	 * on the scheduling logic, this can lead to confusing behaviors - e.g.
+	 * scheduling position not being updated across a priority change.
+	 */
+	void (*dequeue)(struct task_struct *p, u64 deq_flags);
+
+	/**
+	 * @dispatch: Dispatch tasks from the BPF scheduler and/or user DSQs
+	 * @cpu: CPU to dispatch tasks for
+	 * @prev: previous task being switched out
+	 *
+	 * Called when a CPU's local dsq is empty. The operation should dispatch
+	 * one or more tasks from the BPF scheduler into the DSQs using
+	 * scx_bpf_dsq_insert() and/or move from user DSQs into the local DSQ
+	 * using scx_bpf_dsq_move_to_local().
+	 *
+	 * The maximum number of times scx_bpf_dsq_insert() can be called
+	 * without an intervening scx_bpf_dsq_move_to_local() is specified by
+	 * ops.dispatch_max_batch. See the comments on top of the two functions
+	 * for more details.
+	 *
+	 * When not %NULL, @prev is an SCX task with its slice depleted. If
+	 * @prev is still runnable as indicated by set %SCX_TASK_QUEUED in
+	 * @prev->scx.flags, it is not enqueued yet and will be enqueued after
+	 * ops.dispatch() returns. To keep executing @prev, return without
+	 * dispatching or moving any tasks. Also see %SCX_OPS_ENQ_LAST.
+	 */
+	void (*dispatch)(s32 cpu, struct task_struct *prev);
+
+	/**
+	 * @tick: Periodic tick
+	 * @p: task running currently
+	 *
+	 * This operation is called every 1/HZ seconds on CPUs which are
+	 * executing an SCX task. Setting @p->scx.slice to 0 will trigger an
+	 * immediate dispatch cycle on the CPU.
+	 */
+	void (*tick)(struct task_struct *p);
+
+	/**
+	 * @runnable: A task is becoming runnable on its associated CPU
+	 * @p: task becoming runnable
+	 * @enq_flags: %SCX_ENQ_*
+	 *
+	 * This and the following three functions can be used to track a task's
+	 * execution state transitions. A task becomes ->runnable() on a CPU,
+	 * and then goes through one or more ->running() and ->stopping() pairs
+	 * as it runs on the CPU, and eventually becomes ->quiescent() when it's
+	 * done running on the CPU.
+	 *
+	 * @p is becoming runnable on the CPU because it's
+	 *
+	 * - waking up (%SCX_ENQ_WAKEUP)
+	 * - being moved from another CPU
+	 * - being restored after temporarily taken off the queue for an
+	 *   attribute change.
+	 *
+	 * This and ->enqueue() are related but not coupled. This operation
+	 * notifies @p's state transition and may not be followed by ->enqueue()
+	 * e.g. when @p is being dispatched to a remote CPU, or when @p is
+	 * being enqueued on a CPU experiencing a hotplug event. Likewise, a
+	 * task may be ->enqueue()'d without being preceded by this operation
+	 * e.g. after exhausting its slice.
+	 */
+	void (*runnable)(struct task_struct *p, u64 enq_flags);
+
+	/**
+	 * @running: A task is starting to run on its associated CPU
+	 * @p: task starting to run
+	 *
+	 * Note that this callback may be called from a CPU other than the
+	 * one the task is going to run on. This can happen when a task
+	 * property is changed (i.e., affinity), since scx_next_task_scx(),
+	 * which triggers this callback, may run on a CPU different from
+	 * the task's assigned CPU.
+	 *
+	 * Therefore, always use scx_bpf_task_cpu(@p) to determine the
+	 * target CPU the task is going to use.
+	 *
+	 * See ->runnable() for explanation on the task state notifiers.
+	 */
+	void (*running)(struct task_struct *p);
+
+	/**
+	 * @stopping: A task is stopping execution
+	 * @p: task stopping to run
+	 * @runnable: is task @p still runnable?
+	 *
+	 * Note that this callback may be called from a CPU other than the
+	 * one the task was running on. This can happen when a task
+	 * property is changed (i.e., affinity), since dequeue_task_scx(),
+	 * which triggers this callback, may run on a CPU different from
+	 * the task's assigned CPU.
+	 *
+	 * Therefore, always use scx_bpf_task_cpu(@p) to retrieve the CPU
+	 * the task was running on.
+	 *
+	 * See ->runnable() for explanation on the task state notifiers. If
+	 * !@runnable, ->quiescent() will be invoked after this operation
+	 * returns.
+	 */
+	void (*stopping)(struct task_struct *p, bool runnable);
+
+	/**
+	 * @quiescent: A task is becoming not runnable on its associated CPU
+	 * @p: task becoming not runnable
+	 * @deq_flags: %SCX_DEQ_*
+	 *
+	 * See ->runnable() for explanation on the task state notifiers.
+	 *
+	 * @p is becoming quiescent on the CPU because it's
+	 *
+	 * - sleeping (%SCX_DEQ_SLEEP)
+	 * - being moved to another CPU
+	 * - being temporarily taken off the queue for an attribute change
+	 *   (%SCX_DEQ_SAVE)
+	 *
+	 * This and ->dequeue() are related but not coupled. This operation
+	 * notifies @p's state transition and may not be preceded by ->dequeue()
+	 * e.g. when @p is being dispatched to a remote CPU.
+	 */
+	void (*quiescent)(struct task_struct *p, u64 deq_flags);
+
+	/**
+	 * @yield: Yield CPU
+	 * @from: yielding task
+	 * @to: optional yield target task
+	 *
+	 * If @to is NULL, @from is yielding the CPU to other runnable tasks.
+	 * The BPF scheduler should ensure that other available tasks are
+	 * dispatched before the yielding task. Return value is ignored in this
+	 * case.
+	 *
+	 * If @to is not-NULL, @from wants to yield the CPU to @to. If the bpf
+	 * scheduler can implement the request, return %true; otherwise, %false.
+	 */
+	bool (*yield)(struct task_struct *from, struct task_struct *to);
+
+	/**
+	 * @core_sched_before: Task ordering for core-sched
+	 * @a: task A
+	 * @b: task B
+	 *
+	 * Used by core-sched to determine the ordering between two tasks. See
+	 * Documentation/admin-guide/hw-vuln/core-scheduling.rst for details on
+	 * core-sched.
+	 *
+	 * Both @a and @b are runnable and may or may not currently be queued on
+	 * the BPF scheduler. Should return %true if @a should run before @b.
+	 * %false if there's no required ordering or @b should run before @a.
+	 *
+	 * If not specified, the default is ordering them according to when they
+	 * became runnable.
+	 */
+	bool (*core_sched_before)(struct task_struct *a, struct task_struct *b);
+
+	/**
+	 * @set_weight: Set task weight
+	 * @p: task to set weight for
+	 * @weight: new weight [1..10000]
+	 *
+	 * Update @p's weight to @weight.
+	 */
+	void (*set_weight)(struct task_struct *p, u32 weight);
+
+	/**
+	 * @set_cpumask: Set CPU affinity
+	 * @p: task to set CPU affinity for
+	 * @cpumask: cpumask of cpus that @p can run on
+	 *
+	 * Update @p's CPU affinity to @cpumask.
+	 */
+	void (*set_cpumask)(struct task_struct *p,
+			    const struct cpumask *cpumask);
+
+	/**
+	 * @update_idle: Update the idle state of a CPU
+	 * @cpu: CPU to update the idle state for
+	 * @idle: whether entering or exiting the idle state
+	 *
+	 * This operation is called when @rq's CPU goes or leaves the idle
+	 * state. By default, implementing this operation disables the built-in
+	 * idle CPU tracking and the following helpers become unavailable:
+	 *
+	 * - scx_bpf_select_cpu_dfl()
+	 * - scx_bpf_select_cpu_and()
+	 * - scx_bpf_test_and_clear_cpu_idle()
+	 * - scx_bpf_pick_idle_cpu()
+	 *
+	 * The user also must implement ops.select_cpu() as the default
+	 * implementation relies on scx_bpf_select_cpu_dfl().
+	 *
+	 * Specify the %SCX_OPS_KEEP_BUILTIN_IDLE flag to keep the built-in idle
+	 * tracking.
+	 */
+	void (*update_idle)(s32 cpu, bool idle);
+
+	/**
+	 * @cpu_acquire: A CPU is becoming available to the BPF scheduler
+	 * @cpu: The CPU being acquired by the BPF scheduler.
+	 * @args: Acquire arguments, see the struct definition.
+	 *
+	 * A CPU that was previously released from the BPF scheduler is now once
+	 * again under its control.
+	 */
+	void (*cpu_acquire)(s32 cpu, struct scx_cpu_acquire_args *args);
+
+	/**
+	 * @cpu_release: A CPU is taken away from the BPF scheduler
+	 * @cpu: The CPU being released by the BPF scheduler.
+	 * @args: Release arguments, see the struct definition.
+	 *
+	 * The specified CPU is no longer under the control of the BPF
+	 * scheduler. This could be because it was preempted by a higher
+	 * priority sched_class, though there may be other reasons as well. The
+	 * caller should consult @args->reason to determine the cause.
+	 */
+	void (*cpu_release)(s32 cpu, struct scx_cpu_release_args *args);
+
+	/**
+	 * @init_task: Initialize a task to run in a BPF scheduler
+	 * @p: task to initialize for BPF scheduling
+	 * @args: init arguments, see the struct definition
+	 *
+	 * Either we're loading a BPF scheduler or a new task is being forked.
+	 * Initialize @p for BPF scheduling. This operation may block and can
+	 * be used for allocations, and is called exactly once for a task.
+	 *
+	 * Return 0 for success, -errno for failure. An error return while
+	 * loading will abort loading of the BPF scheduler. During a fork, it
+	 * will abort that specific fork.
+	 */
+	s32 (*init_task)(struct task_struct *p, struct scx_init_task_args *args);
+
+	/**
+	 * @exit_task: Exit a previously-running task from the system
+	 * @p: task to exit
+	 * @args: exit arguments, see the struct definition
+	 *
+	 * @p is exiting or the BPF scheduler is being unloaded. Perform any
+	 * necessary cleanup for @p.
+	 */
+	void (*exit_task)(struct task_struct *p, struct scx_exit_task_args *args);
+
+	/**
+	 * @enable: Enable BPF scheduling for a task
+	 * @p: task to enable BPF scheduling for
+	 *
+	 * Enable @p for BPF scheduling. enable() is called on @p any time it
+	 * enters SCX, and is always paired with a matching disable().
+	 */
+	void (*enable)(struct task_struct *p);
+
+	/**
+	 * @disable: Disable BPF scheduling for a task
+	 * @p: task to disable BPF scheduling for
+	 *
+	 * @p is exiting, leaving SCX or the BPF scheduler is being unloaded.
+	 * Disable BPF scheduling for @p. A disable() call is always matched
+	 * with a prior enable() call.
+	 */
+	void (*disable)(struct task_struct *p);
+
+	/**
+	 * @dump: Dump BPF scheduler state on error
+	 * @ctx: debug dump context
+	 *
+	 * Use scx_bpf_dump() to generate BPF scheduler specific debug dump.
+	 */
+	void (*dump)(struct scx_dump_ctx *ctx);
+
+	/**
+	 * @dump_cpu: Dump BPF scheduler state for a CPU on error
+	 * @ctx: debug dump context
+	 * @cpu: CPU to generate debug dump for
+	 * @idle: @cpu is currently idle without any runnable tasks
+	 *
+	 * Use scx_bpf_dump() to generate BPF scheduler specific debug dump for
+	 * @cpu. If @idle is %true and this operation doesn't produce any
+	 * output, @cpu is skipped for dump.
+	 */
+	void (*dump_cpu)(struct scx_dump_ctx *ctx, s32 cpu, bool idle);
+
+	/**
+	 * @dump_task: Dump BPF scheduler state for a runnable task on error
+	 * @ctx: debug dump context
+	 * @p: runnable task to generate debug dump for
+	 *
+	 * Use scx_bpf_dump() to generate BPF scheduler specific debug dump for
+	 * @p.
+	 */
+	void (*dump_task)(struct scx_dump_ctx *ctx, struct task_struct *p);
+
+#ifdef CONFIG_EXT_GROUP_SCHED
+	/**
+	 * @cgroup_init: Initialize a cgroup
+	 * @cgrp: cgroup being initialized
+	 * @args: init arguments, see the struct definition
+	 *
+	 * Either the BPF scheduler is being loaded or @cgrp created, initialize
+	 * @cgrp for sched_ext. This operation may block.
+	 *
+	 * Return 0 for success, -errno for failure. An error return while
+	 * loading will abort loading of the BPF scheduler. During cgroup
+	 * creation, it will abort the specific cgroup creation.
+	 */
+	s32 (*cgroup_init)(struct cgroup *cgrp,
+			   struct scx_cgroup_init_args *args);
+
+	/**
+	 * @cgroup_exit: Exit a cgroup
+	 * @cgrp: cgroup being exited
+	 *
+	 * Either the BPF scheduler is being unloaded or @cgrp destroyed, exit
+	 * @cgrp for sched_ext. This operation my block.
+	 */
+	void (*cgroup_exit)(struct cgroup *cgrp);
+
+	/**
+	 * @cgroup_prep_move: Prepare a task to be moved to a different cgroup
+	 * @p: task being moved
+	 * @from: cgroup @p is being moved from
+	 * @to: cgroup @p is being moved to
+	 *
+	 * Prepare @p for move from cgroup @from to @to. This operation may
+	 * block and can be used for allocations.
+	 *
+	 * Return 0 for success, -errno for failure. An error return aborts the
+	 * migration.
+	 */
+	s32 (*cgroup_prep_move)(struct task_struct *p,
+				struct cgroup *from, struct cgroup *to);
+
+	/**
+	 * @cgroup_move: Commit cgroup move
+	 * @p: task being moved
+	 * @from: cgroup @p is being moved from
+	 * @to: cgroup @p is being moved to
+	 *
+	 * Commit the move. @p is dequeued during this operation.
+	 */
+	void (*cgroup_move)(struct task_struct *p,
+			    struct cgroup *from, struct cgroup *to);
+
+	/**
+	 * @cgroup_cancel_move: Cancel cgroup move
+	 * @p: task whose cgroup move is being canceled
+	 * @from: cgroup @p was being moved from
+	 * @to: cgroup @p was being moved to
+	 *
+	 * @p was cgroup_prep_move()'d but failed before reaching cgroup_move().
+	 * Undo the preparation.
+	 */
+	void (*cgroup_cancel_move)(struct task_struct *p,
+				   struct cgroup *from, struct cgroup *to);
+
+	/**
+	 * @cgroup_set_weight: A cgroup's weight is being changed
+	 * @cgrp: cgroup whose weight is being updated
+	 * @weight: new weight [1..10000]
+	 *
+	 * Update @cgrp's weight to @weight.
+	 */
+	void (*cgroup_set_weight)(struct cgroup *cgrp, u32 weight);
+
+	/**
+	 * @cgroup_set_bandwidth: A cgroup's bandwidth is being changed
+	 * @cgrp: cgroup whose bandwidth is being updated
+	 * @period_us: bandwidth control period
+	 * @quota_us: bandwidth control quota
+	 * @burst_us: bandwidth control burst
+	 *
+	 * Update @cgrp's bandwidth control parameters. This is from the cpu.max
+	 * cgroup interface.
+	 *
+	 * @quota_us / @period_us determines the CPU bandwidth @cgrp is entitled
+	 * to. For example, if @period_us is 1_000_000 and @quota_us is
+	 * 2_500_000. @cgrp is entitled to 2.5 CPUs. @burst_us can be
+	 * interpreted in the same fashion and specifies how much @cgrp can
+	 * burst temporarily. The specific control mechanism and thus the
+	 * interpretation of @period_us and burstiness is upto to the BPF
+	 * scheduler.
+	 */
+	void (*cgroup_set_bandwidth)(struct cgroup *cgrp,
+				     u64 period_us, u64 quota_us, u64 burst_us);
+
+#endif	/* CONFIG_EXT_GROUP_SCHED */
+
+	/*
+	 * All online ops must come before ops.cpu_online().
+	 */
+
+	/**
+	 * @cpu_online: A CPU became online
+	 * @cpu: CPU which just came up
+	 *
+	 * @cpu just came online. @cpu will not call ops.enqueue() or
+	 * ops.dispatch(), nor run tasks associated with other CPUs beforehand.
+	 */
+	void (*cpu_online)(s32 cpu);
+
+	/**
+	 * @cpu_offline: A CPU is going offline
+	 * @cpu: CPU which is going offline
+	 *
+	 * @cpu is going offline. @cpu will not call ops.enqueue() or
+	 * ops.dispatch(), nor run tasks associated with other CPUs afterwards.
+	 */
+	void (*cpu_offline)(s32 cpu);
+
+	/*
+	 * All CPU hotplug ops must come before ops.init().
+	 */
+
+	/**
+	 * @init: Initialize the BPF scheduler
+	 */
+	s32 (*init)(void);
+
+	/**
+	 * @exit: Clean up after the BPF scheduler
+	 * @info: Exit info
+	 *
+	 * ops.exit() is also called on ops.init() failure, which is a bit
+	 * unusual. This is to allow rich reporting through @info on how
+	 * ops.init() failed.
+	 */
+	void (*exit)(struct scx_exit_info *info);
+
+	/**
+	 * @dispatch_max_batch: Max nr of tasks that dispatch() can dispatch
+	 */
+	u32 dispatch_max_batch;
+
+	/**
+	 * @flags: %SCX_OPS_* flags
+	 */
+	u64 flags;
+
+	/**
+	 * @timeout_ms: The maximum amount of time, in milliseconds, that a
+	 * runnable task should be able to wait before being scheduled. The
+	 * maximum timeout may not exceed the default timeout of 30 seconds.
+	 *
+	 * Defaults to the maximum allowed timeout value of 30 seconds.
+	 */
+	u32 timeout_ms;
+
+	/**
+	 * @exit_dump_len: scx_exit_info.dump buffer length. If 0, the default
+	 * value of 32768 is used.
+	 */
+	u32 exit_dump_len;
+
+	/**
+	 * @hotplug_seq: A sequence number that may be set by the scheduler to
+	 * detect when a hotplug event has occurred during the loading process.
+	 * If 0, no detection occurs. Otherwise, the scheduler will fail to
+	 * load if the sequence number does not match @scx_hotplug_seq on the
+	 * enable path.
+	 */
+	u64 hotplug_seq;
+
+	/**
+	 * @name: BPF scheduler's name
+	 *
+	 * Must be a non-zero valid BPF object name including only isalnum(),
+	 * '_' and '.' chars. Shows up in kernel.sched_ext_ops sysctl while the
+	 * BPF scheduler is enabled.
+	 */
+	char name[SCX_OPS_NAME_LEN];
+
+	/* internal use only, must be NULL */
+	void *priv;
+};
+
+enum scx_opi {
+	SCX_OPI_BEGIN			= 0,
+	SCX_OPI_NORMAL_BEGIN		= 0,
+	SCX_OPI_NORMAL_END		= SCX_OP_IDX(cpu_online),
+	SCX_OPI_CPU_HOTPLUG_BEGIN	= SCX_OP_IDX(cpu_online),
+	SCX_OPI_CPU_HOTPLUG_END		= SCX_OP_IDX(init),
+	SCX_OPI_END			= SCX_OP_IDX(init),
+};
+
+/*
+ * Collection of event counters. Event types are placed in descending order.
+ */
+struct scx_event_stats {
+	/*
+	 * If ops.select_cpu() returns a CPU which can't be used by the task,
+	 * the core scheduler code silently picks a fallback CPU.
+	 */
+	s64		SCX_EV_SELECT_CPU_FALLBACK;
+
+	/*
+	 * When dispatching to a local DSQ, the CPU may have gone offline in
+	 * the meantime. In this case, the task is bounced to the global DSQ.
+	 */
+	s64		SCX_EV_DISPATCH_LOCAL_DSQ_OFFLINE;
+
+	/*
+	 * If SCX_OPS_ENQ_LAST is not set, the number of times that a task
+	 * continued to run because there were no other tasks on the CPU.
+	 */
+	s64		SCX_EV_DISPATCH_KEEP_LAST;
+
+	/*
+	 * If SCX_OPS_ENQ_EXITING is not set, the number of times that a task
+	 * is dispatched to a local DSQ when exiting.
+	 */
+	s64		SCX_EV_ENQ_SKIP_EXITING;
+
+	/*
+	 * If SCX_OPS_ENQ_MIGRATION_DISABLED is not set, the number of times a
+	 * migration disabled task skips ops.enqueue() and is dispatched to its
+	 * local DSQ.
+	 */
+	s64		SCX_EV_ENQ_SKIP_MIGRATION_DISABLED;
+
+	/*
+	 * Total number of times a task's time slice was refilled with the
+	 * default value (SCX_SLICE_DFL).
+	 */
+	s64		SCX_EV_REFILL_SLICE_DFL;
+
+	/*
+	 * The total duration of bypass modes in nanoseconds.
+	 */
+	s64		SCX_EV_BYPASS_DURATION;
+
+	/*
+	 * The number of tasks dispatched in the bypassing mode.
+	 */
+	s64		SCX_EV_BYPASS_DISPATCH;
+
+	/*
+	 * The number of times the bypassing mode has been activated.
+	 */
+	s64		SCX_EV_BYPASS_ACTIVATE;
+};
+
+struct scx_sched {
+	struct sched_ext_ops	ops;
+	DECLARE_BITMAP(has_op, SCX_OPI_END);
+
+	/*
+	 * Dispatch queues.
+	 *
+	 * The global DSQ (%SCX_DSQ_GLOBAL) is split per-node for scalability.
+	 * This is to avoid live-locking in bypass mode where all tasks are
+	 * dispatched to %SCX_DSQ_GLOBAL and all CPUs consume from it. If
+	 * per-node split isn't sufficient, it can be further split.
+	 */
+	struct rhashtable	dsq_hash;
+	struct scx_dispatch_q	**global_dsqs;
+
+	/*
+	 * The event counters are in a per-CPU variable to minimize the
+	 * accounting overhead. A system-wide view on the event counter is
+	 * constructed when requested by scx_bpf_events().
+	 */
+	struct scx_event_stats __percpu *event_stats_cpu;
+
+	bool			warned_zero_slice;
+
+	atomic_t		exit_kind;
+	struct scx_exit_info	*exit_info;
+
+	struct kobject		kobj;
+
+	struct kthread_worker	*helper;
+	struct irq_work		error_irq_work;
+	struct kthread_work	disable_work;
+	struct rcu_work		rcu_work;
+};
+
+enum scx_wake_flags {
+	/* expose select WF_* flags as enums */
+	SCX_WAKE_FORK		= WF_FORK,
+	SCX_WAKE_TTWU		= WF_TTWU,
+	SCX_WAKE_SYNC		= WF_SYNC,
+};
+
+enum scx_enq_flags {
+	/* expose select ENQUEUE_* flags as enums */
+	SCX_ENQ_WAKEUP		= ENQUEUE_WAKEUP,
+	SCX_ENQ_HEAD		= ENQUEUE_HEAD,
+	SCX_ENQ_CPU_SELECTED	= ENQUEUE_RQ_SELECTED,
+
+	/* high 32bits are SCX specific */
+
+	/*
+	 * Set the following to trigger preemption when calling
+	 * scx_bpf_dsq_insert() with a local dsq as the target. The slice of the
+	 * current task is cleared to zero and the CPU is kicked into the
+	 * scheduling path. Implies %SCX_ENQ_HEAD.
+	 */
+	SCX_ENQ_PREEMPT		= 1LLU << 32,
+
+	/*
+	 * The task being enqueued was previously enqueued on the current CPU's
+	 * %SCX_DSQ_LOCAL, but was removed from it in a call to the
+	 * scx_bpf_reenqueue_local() kfunc. If scx_bpf_reenqueue_local() was
+	 * invoked in a ->cpu_release() callback, and the task is again
+	 * dispatched back to %SCX_LOCAL_DSQ by this current ->enqueue(), the
+	 * task will not be scheduled on the CPU until at least the next invocation
+	 * of the ->cpu_acquire() callback.
+	 */
+	SCX_ENQ_REENQ		= 1LLU << 40,
+
+	/*
+	 * The task being enqueued is the only task available for the cpu. By
+	 * default, ext core keeps executing such tasks but when
+	 * %SCX_OPS_ENQ_LAST is specified, they're ops.enqueue()'d with the
+	 * %SCX_ENQ_LAST flag set.
+	 *
+	 * The BPF scheduler is responsible for triggering a follow-up
+	 * scheduling event. Otherwise, Execution may stall.
+	 */
+	SCX_ENQ_LAST		= 1LLU << 41,
+
+	/* high 8 bits are internal */
+	__SCX_ENQ_INTERNAL_MASK	= 0xffLLU << 56,
+
+	SCX_ENQ_CLEAR_OPSS	= 1LLU << 56,
+	SCX_ENQ_DSQ_PRIQ	= 1LLU << 57,
+};
+
+enum scx_deq_flags {
+	/* expose select DEQUEUE_* flags as enums */
+	SCX_DEQ_SLEEP		= DEQUEUE_SLEEP,
+
+	/* high 32bits are SCX specific */
+
+	/*
+	 * The generic core-sched layer decided to execute the task even though
+	 * it hasn't been dispatched yet. Dequeue from the BPF side.
+	 */
+	SCX_DEQ_CORE_SCHED_EXEC	= 1LLU << 32,
+};
+
+enum scx_pick_idle_cpu_flags {
+	SCX_PICK_IDLE_CORE	= 1LLU << 0,	/* pick a CPU whose SMT siblings are also idle */
+	SCX_PICK_IDLE_IN_NODE	= 1LLU << 1,	/* pick a CPU in the same target NUMA node */
+};
+
+enum scx_kick_flags {
+	/*
+	 * Kick the target CPU if idle. Guarantees that the target CPU goes
+	 * through at least one full scheduling cycle before going idle. If the
+	 * target CPU can be determined to be currently not idle and going to go
+	 * through a scheduling cycle before going idle, noop.
+	 */
+	SCX_KICK_IDLE		= 1LLU << 0,
+
+	/*
+	 * Preempt the current task and execute the dispatch path. If the
+	 * current task of the target CPU is an SCX task, its ->scx.slice is
+	 * cleared to zero before the scheduling path is invoked so that the
+	 * task expires and the dispatch path is invoked.
+	 */
+	SCX_KICK_PREEMPT	= 1LLU << 1,
+
+	/*
+	 * Wait for the CPU to be rescheduled. The scx_bpf_kick_cpu() call will
+	 * return after the target CPU finishes picking the next task.
+	 */
+	SCX_KICK_WAIT		= 1LLU << 2,
+};
+
+enum scx_tg_flags {
+	SCX_TG_ONLINE		= 1U << 0,
+	SCX_TG_INITED		= 1U << 1,
+};
+
+enum scx_enable_state {
+	SCX_ENABLING,
+	SCX_ENABLED,
+	SCX_DISABLING,
+	SCX_DISABLED,
+};
+
+static const char *scx_enable_state_str[] = {
+	[SCX_ENABLING]		= "enabling",
+	[SCX_ENABLED]		= "enabled",
+	[SCX_DISABLING]		= "disabling",
+	[SCX_DISABLED]		= "disabled",
+};
+
+/*
+ * sched_ext_entity->ops_state
+ *
+ * Used to track the task ownership between the SCX core and the BPF scheduler.
+ * State transitions look as follows:
+ *
+ * NONE -> QUEUEING -> QUEUED -> DISPATCHING
+ *   ^              |                 |
+ *   |              v                 v
+ *   \-------------------------------/
+ *
+ * QUEUEING and DISPATCHING states can be waited upon. See wait_ops_state() call
+ * sites for explanations on the conditions being waited upon and why they are
+ * safe. Transitions out of them into NONE or QUEUED must store_release and the
+ * waiters should load_acquire.
+ *
+ * Tracking scx_ops_state enables sched_ext core to reliably determine whether
+ * any given task can be dispatched by the BPF scheduler at all times and thus
+ * relaxes the requirements on the BPF scheduler. This allows the BPF scheduler
+ * to try to dispatch any task anytime regardless of its state as the SCX core
+ * can safely reject invalid dispatches.
+ */
+enum scx_ops_state {
+	SCX_OPSS_NONE,		/* owned by the SCX core */
+	SCX_OPSS_QUEUEING,	/* in transit to the BPF scheduler */
+	SCX_OPSS_QUEUED,	/* owned by the BPF scheduler */
+	SCX_OPSS_DISPATCHING,	/* in transit back to the SCX core */
+
+	/*
+	 * QSEQ brands each QUEUED instance so that, when dispatch races
+	 * dequeue/requeue, the dispatcher can tell whether it still has a claim
+	 * on the task being dispatched.
+	 *
+	 * As some 32bit archs can't do 64bit store_release/load_acquire,
+	 * p->scx.ops_state is atomic_long_t which leaves 30 bits for QSEQ on
+	 * 32bit machines. The dispatch race window QSEQ protects is very narrow
+	 * and runs with IRQ disabled. 30 bits should be sufficient.
+	 */
+	SCX_OPSS_QSEQ_SHIFT	= 2,
+};
+
+/* Use macros to ensure that the type is unsigned long for the masks */
+#define SCX_OPSS_STATE_MASK	((1LU << SCX_OPSS_QSEQ_SHIFT) - 1)
+#define SCX_OPSS_QSEQ_MASK	(~SCX_OPSS_STATE_MASK)
+
+DECLARE_PER_CPU(struct rq *, scx_locked_rq_state);
+
+/*
+ * Return the rq currently locked from an scx callback, or NULL if no rq is
+ * locked.
+ */
+static inline struct rq *scx_locked_rq(void)
+{
+	return __this_cpu_read(scx_locked_rq_state);
+}
+
+static inline bool scx_kf_allowed_if_unlocked(void)
+{
+	return !current->scx.kf_mask;
+}
+
+static inline bool scx_rq_bypassing(struct rq *rq)
+{
+	return unlikely(rq->scx.flags & SCX_RQ_BYPASSING);
+}