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bsd/pthread/pthread_workqueue.c xnu-12377.121.6 xnu-6153.41.3
--- xnu/xnu-12377.121.6/bsd/pthread/pthread_workqueue.c
+++ xnu/xnu-6153.41.3/bsd/pthread/pthread_workqueue.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000-2020 Apple Inc. All rights reserved.
+ * Copyright (c) 2000-2017 Apple Inc. All rights reserved.
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  *
@@ -39,9 +39,7 @@
 #include <kern/sched_prim.h>    /* for thread_exception_return */
 #include <kern/task.h>
 #include <kern/thread.h>
-#include <kern/thread_group.h>
 #include <kern/zalloc.h>
-#include <kern/work_interval.h>
 #include <mach/kern_return.h>
 #include <mach/mach_param.h>
 #include <mach/mach_port.h>
@@ -56,9 +54,7 @@
 #include <mach/vm_statistics.h>
 #include <machine/atomic.h>
 #include <machine/machine_routines.h>
-#include <machine/smp.h>
 #include <vm/vm_map.h>
-#include <vm/vm_fault_xnu.h>
 #include <vm/vm_protos.h>
 
 #include <sys/eventvar.h>
@@ -84,13 +80,6 @@
 #include <os/log.h>
 
 static void workq_unpark_continue(void *uth, wait_result_t wr) __dead2;
-
-static void workq_bound_thread_unpark_continue(void *uth, wait_result_t wr) __dead2;
-
-static void workq_bound_thread_initialize_and_unpark_continue(void *uth, wait_result_t wr) __dead2;
-
-static void workq_bound_thread_setup_and_run(struct uthread *uth, int setup_flags) __dead2;
-
 static void workq_schedule_creator(proc_t p, struct workqueue *wq,
     workq_kern_threadreq_flags_t flags);
 
@@ -98,24 +87,12 @@
     workq_threadreq_t req);
 
 static uint32_t workq_constrained_allowance(struct workqueue *wq,
-    thread_qos_t at_qos, struct uthread *uth,
-    bool may_start_timer, bool record_failed_allowance);
-
-static bool _wq_cooperative_queue_refresh_best_req_qos(struct workqueue *wq);
+    thread_qos_t at_qos, struct uthread *uth, bool may_start_timer);
 
 static bool workq_thread_is_busy(uint64_t cur_ts,
     _Atomic uint64_t *lastblocked_tsp);
 
 static int workq_sysctl_handle_usecs SYSCTL_HANDLER_ARGS;
-
-static bool
-workq_schedule_delayed_thread_creation(struct workqueue *wq, int flags);
-
-static inline void
-workq_lock_spin(struct workqueue *wq);
-
-static inline void
-workq_unlock(struct workqueue *wq);
 
 #pragma mark globals
 
@@ -130,15 +107,14 @@
 	                        CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, &var, 0, \
 	                        workq_sysctl_handle_usecs, "I", "")
 
-static LCK_GRP_DECLARE(workq_lck_grp, "workq");
+static lck_grp_t      *workq_lck_grp;
+static lck_attr_t     *workq_lck_attr;
+static lck_grp_attr_t *workq_lck_grp_attr;
 os_refgrp_decl(static, workq_refgrp, "workq", NULL);
 
-static ZONE_DEFINE(workq_zone_workqueue, "workq.wq",
-    sizeof(struct workqueue), ZC_NONE);
-static ZONE_DEFINE(workq_zone_threadreq, "workq.threadreq",
-    sizeof(struct workq_threadreq_s), ZC_CACHING);
-
 static struct mpsc_daemon_queue workq_deallocate_queue;
+static zone_t workq_zone_workqueue;
+static zone_t workq_zone_threadreq;
 
 WORKQ_SYSCTL_USECS(wq_stalled_window, WQ_STALLED_WINDOW_USECS);
 WORKQ_SYSCTL_USECS(wq_reduce_pool_window, WQ_REDUCE_POOL_WINDOW_USECS);
@@ -149,20 +125,6 @@
 static uint16_t wq_death_max_load;
 static uint32_t wq_max_parallelism[WORKQ_NUM_QOS_BUCKETS];
 
-/*
- * This is not a hard limit but the max size we want to aim to hit across the
- * entire cooperative pool. We can oversubscribe the pool due to non-cooperative
- * workers and the max we will oversubscribe the pool by, is a total of
- * wq_max_cooperative_threads * WORKQ_NUM_QOS_BUCKETS.
- */
-static uint32_t wq_max_cooperative_threads;
-
-static inline uint32_t
-wq_cooperative_queue_max_size(struct workqueue *wq)
-{
-	return wq->wq_cooperative_queue_has_limited_max_size ? 1 : wq_max_cooperative_threads;
-}
-
 #pragma mark sysctls
 
 static int
@@ -185,60 +147,6 @@
 SYSCTL_INT(_kern, OID_AUTO, wq_max_constrained_threads, CTLFLAG_RW | CTLFLAG_LOCKED,
     &wq_max_constrained_threads, 0, "");
 
-static int
-wq_limit_cooperative_threads_for_proc SYSCTL_HANDLER_ARGS
-{
-#pragma unused(arg1, arg2, oidp)
-	int input_pool_size = 0;
-	int changed;
-	int error = 0;
-
-	error = sysctl_io_number(req, 0, sizeof(int), &input_pool_size, &changed);
-	if (error || !changed) {
-		return error;
-	}
-
-#define WQ_COOPERATIVE_POOL_SIZE_DEFAULT 0
-#define WQ_COOPERATIVE_POOL_SIZE_STRICT_PER_QOS -1
-/* Not available currently, but sysctl interface is designed to allow these
- * extra parameters:
- *		WQ_COOPERATIVE_POOL_SIZE_STRICT : -2 (across all bucket)
- *		WQ_COOPERATIVE_POOL_SIZE_CUSTOM : [1, 512]
- */
-
-	if (input_pool_size != WQ_COOPERATIVE_POOL_SIZE_DEFAULT
-	    && input_pool_size != WQ_COOPERATIVE_POOL_SIZE_STRICT_PER_QOS) {
-		error = EINVAL;
-		goto out;
-	}
-
-	proc_t p = req->p;
-	struct workqueue *wq = proc_get_wqptr(p);
-
-	if (wq != NULL) {
-		workq_lock_spin(wq);
-		if (wq->wq_reqcount > 0 || wq->wq_nthreads > 0) {
-			// Hackily enforce that the workqueue is still new (no requests or
-			// threads)
-			error = ENOTSUP;
-		} else {
-			wq->wq_cooperative_queue_has_limited_max_size = (input_pool_size == WQ_COOPERATIVE_POOL_SIZE_STRICT_PER_QOS);
-		}
-		workq_unlock(wq);
-	} else {
-		/* This process has no workqueue, calling this syctl makes no sense */
-		return ENOTSUP;
-	}
-
-out:
-	return error;
-}
-
-SYSCTL_PROC(_kern, OID_AUTO, wq_limit_cooperative_threads,
-    CTLFLAG_ANYBODY | CTLFLAG_MASKED | CTLFLAG_WR | CTLFLAG_LOCKED | CTLTYPE_INT, 0, 0,
-    wq_limit_cooperative_threads_for_proc,
-    "I", "Modify the max pool size of the cooperative pool");
-
 #pragma mark p_wqptr
 
 #define WQPTR_IS_INITING_VALUE ((struct workqueue *)~(uintptr_t)0)
@@ -249,7 +157,7 @@
 	return os_atomic_load(&p->p_wqptr, relaxed);
 }
 
-struct workqueue *
+static struct workqueue *
 proc_get_wqptr(struct proc *p)
 {
 	struct workqueue *wq = proc_get_wqptr_fast(p);
@@ -300,7 +208,7 @@
 static inline void
 workq_thread_wakeup(struct uthread *uth)
 {
-	thread_wakeup_thread(workq_parked_wait_event(uth), get_machthread(uth));
+	thread_wakeup_thread(workq_parked_wait_event(uth), uth->uu_thread);
 }
 
 #pragma mark wq_thactive
@@ -332,7 +240,7 @@
 	return os_atomic_load_wide(&wq->wq_thactive, relaxed);
 }
 
-static inline uint8_t
+static inline int
 _wq_bucket(thread_qos_t qos)
 {
 	// Map both BG and MT to the same bucket by over-shifting down and
@@ -346,7 +254,7 @@
 }
 
 #define WQ_THACTIVE_BEST_CONSTRAINED_REQ_QOS(tha) \
-	        ((thread_qos_t)((tha) >> WQ_THACTIVE_QOS_SHIFT))
+	        ((tha) >> WQ_THACTIVE_QOS_SHIFT)
 
 static inline thread_qos_t
 _wq_thactive_best_constrained_req_qos(struct workqueue *wq)
@@ -377,9 +285,9 @@
 		v = os_atomic_add(&wq->wq_thactive, v, relaxed);
 #ifdef __LP64__
 		WQ_TRACE_WQ(TRACE_wq_thactive_update, wq, (uint64_t)v,
-		    (uint64_t)(v >> 64), 0);
+		    (uint64_t)(v >> 64), 0, 0);
 #else
-		WQ_TRACE_WQ(TRACE_wq_thactive_update, wq, v, 0, 0);
+		WQ_TRACE_WQ(TRACE_wq_thactive_update, wq, v, 0, 0, 0);
 #endif
 	}
 }
@@ -387,9 +295,7 @@
 static inline wq_thactive_t
 _wq_thactive_offset_for_qos(thread_qos_t qos)
 {
-	uint8_t bucket = _wq_bucket(qos);
-	__builtin_assume(bucket < WORKQ_NUM_BUCKETS);
-	return (wq_thactive_t)1 << (bucket * WQ_THACTIVE_BUCKET_WIDTH);
+	return (wq_thactive_t)1 << (_wq_bucket(qos) * WQ_THACTIVE_BUCKET_WIDTH);
 }
 
 static inline wq_thactive_t
@@ -434,7 +340,7 @@
 		*max_busycount = THREAD_QOS_LAST - qos;
 	}
 
-	uint8_t i = _wq_bucket(qos);
+	int i = _wq_bucket(qos);
 	v >>= i * WQ_THACTIVE_BUCKET_WIDTH;
 	for (; i < WORKQ_NUM_QOS_BUCKETS; i++, v >>= WQ_THACTIVE_BUCKET_WIDTH) {
 		active = v & WQ_THACTIVE_BUCKET_MASK;
@@ -456,24 +362,6 @@
 	return count;
 }
 
-/* The input qos here should be the requested QoS of the thread, not accounting
- * for any overrides */
-static inline void
-_wq_cooperative_queue_scheduled_count_dec(struct workqueue *wq, thread_qos_t qos)
-{
-	__assert_only uint8_t old_scheduled_count = wq->wq_cooperative_queue_scheduled_count[_wq_bucket(qos)]--;
-	assert(old_scheduled_count > 0);
-}
-
-/* The input qos here should be the requested QoS of the thread, not accounting
- * for any overrides */
-static inline void
-_wq_cooperative_queue_scheduled_count_inc(struct workqueue *wq, thread_qos_t qos)
-{
-	__assert_only uint8_t old_scheduled_count = wq->wq_cooperative_queue_scheduled_count[_wq_bucket(qos)]++;
-	assert(old_scheduled_count < UINT8_MAX);
-}
-
 #pragma mark wq_flags
 
 static inline uint32_t
@@ -495,37 +383,36 @@
 	return !wq || _wq_exiting(wq);
 }
 
-
 #pragma mark workqueue lock
 
 static bool
-workq_lock_is_acquired_kdp(struct workqueue *wq)
-{
-	return kdp_lck_ticket_is_acquired(&wq->wq_lock);
+workq_lock_spin_is_acquired_kdp(struct workqueue *wq)
+{
+	return kdp_lck_spin_is_acquired(&wq->wq_lock);
 }
 
 static inline void
 workq_lock_spin(struct workqueue *wq)
 {
-	lck_ticket_lock(&wq->wq_lock, &workq_lck_grp);
+	lck_spin_lock_grp(&wq->wq_lock, workq_lck_grp);
 }
 
 static inline void
-workq_lock_held(struct workqueue *wq)
-{
-	LCK_TICKET_ASSERT_OWNED(&wq->wq_lock);
+workq_lock_held(__assert_only struct workqueue *wq)
+{
+	LCK_SPIN_ASSERT(&wq->wq_lock, LCK_ASSERT_OWNED);
 }
 
 static inline bool
 workq_lock_try(struct workqueue *wq)
 {
-	return lck_ticket_lock_try(&wq->wq_lock, &workq_lck_grp);
+	return lck_spin_try_lock_grp(&wq->wq_lock, workq_lck_grp);
 }
 
 static inline void
 workq_unlock(struct workqueue *wq)
 {
-	lck_ticket_unlock(&wq->wq_lock);
+	lck_spin_unlock(&wq->wq_lock);
 }
 
 #pragma mark idle thread lists
@@ -574,7 +461,7 @@
 		return true;
 	}
 
-	if ((req_flags & TRP_POLICY) && req_trp.trp_pol != cur_trp.trp_pol) {
+	if ((req_flags & TRP_POLICY) && cur_trp.trp_pol != cur_trp.trp_pol) {
 		return true;
 	}
 
@@ -588,40 +475,14 @@
 		return true;
 	}
 
-	if (req->tr_qos != workq_pri_override(uth->uu_workq_pri)) {
-		return true;
-	}
-
-#if CONFIG_PREADOPT_TG
-	thread_group_qos_t tg = kqr_preadopt_thread_group(req);
-	if (KQWL_HAS_VALID_PREADOPTED_TG(tg)) {
-		/*
-		 * Ideally, we'd add check here to see if thread's preadopt TG is same
-		 * as the thread requests's thread group and short circuit if that is
-		 * the case. But in the interest of keeping the code clean and not
-		 * taking the thread lock here, we're going to skip this. We will
-		 * eventually shortcircuit once we try to set the preadoption thread
-		 * group on the thread.
-		 */
-		return true;
-	}
-#endif
-
-	return false;
-}
-
-/* Input thread must be self. Called during self override, resetting overrides
- * or while processing kevents
- *
- * Called with workq lock held. Sometimes also the thread mutex
- */
+	return req->tr_qos != workq_pri_override(uth->uu_workq_pri);
+}
+
 static void
 workq_thread_update_bucket(proc_t p, struct workqueue *wq, struct uthread *uth,
     struct uu_workq_policy old_pri, struct uu_workq_policy new_pri,
     bool force_run)
 {
-	assert(uth == current_uthread());
-
 	thread_qos_t old_bucket = old_pri.qos_bucket;
 	thread_qos_t new_bucket = workq_pri_bucket(new_pri);
 
@@ -632,12 +493,11 @@
 	new_pri.qos_bucket = new_bucket;
 	uth->uu_workq_pri = new_pri;
 
-	if (old_pri.qos_override != new_pri.qos_override) {
-		thread_set_workq_override(get_machthread(uth), new_pri.qos_override);
-	}
-
-	if (wq->wq_reqcount &&
-	    (old_bucket > new_bucket || force_run)) {
+	if (workq_pri_override(old_pri) != new_bucket) {
+		thread_set_workq_override(uth->uu_thread, new_bucket);
+	}
+
+	if (wq->wq_reqcount && (old_bucket > new_bucket || force_run)) {
 		int flags = WORKQ_THREADREQ_CAN_CREATE_THREADS;
 		if (old_bucket > new_bucket) {
 			/*
@@ -686,16 +546,11 @@
 	}
 }
 
-/*
- * This function is always called with the workq lock, except for the
- * permanently bound workqueue thread, which instead requires the kqlock.
- * See locking model for bound thread's uu_workq_flags.
- */
 static void
 workq_thread_reset_pri(struct workqueue *wq, struct uthread *uth,
     workq_threadreq_t req, bool unpark)
 {
-	thread_t th = get_machthread(uth);
+	thread_t th = uth->uu_thread;
 	thread_qos_t qos = req ? req->tr_qos : WORKQ_THREAD_QOS_CLEANUP;
 	workq_threadreq_param_t trp = { };
 	int priority = 31;
@@ -718,7 +573,7 @@
 		uint32_t mgr_pri = wq->wq_event_manager_priority;
 		assert(trp.trp_value == 0); // manager qos and thread policy don't mix
 
-		if (_pthread_priority_has_sched_pri(mgr_pri)) {
+		if (mgr_pri & _PTHREAD_PRIORITY_SCHED_PRI_FLAG) {
 			mgr_pri &= _PTHREAD_PRIORITY_SCHED_PRI_MASK;
 			thread_set_workq_pri(th, THREAD_QOS_UNSPECIFIED, mgr_pri,
 			    POLICY_TIMESHARE);
@@ -738,85 +593,6 @@
 		}
 	}
 
-#if CONFIG_PREADOPT_TG
-	if (req && (req->tr_flags & WORKQ_TR_FLAG_WORKLOOP)) {
-		/*
-		 * For kqwl permanently configured with a thread group, we can safely borrow
-		 * +1 ref from kqwl_preadopt_tg. A thread then takes additional +1 ref
-		 * for itself via thread_set_preadopt_thread_group.
-		 *
-		 * In all other cases, we cannot safely read and borrow the reference from the kqwl
-		 * since it can disappear from under us at any time due to the max-ing logic in
-		 * kqueue_set_preadopted_thread_group.
-		 *
-		 * As such, we do the following dance:
-		 *
-		 * 1) cmpxchng and steal the kqwl's preadopt thread group and leave
-		 * behind with (NULL + QoS). At this point, we have the reference
-		 * to the thread group from the kqwl.
-		 * 2) Have the thread set the preadoption thread group on itself.
-		 * 3) cmpxchng from (NULL + QoS) which we set earlier in (1), back to
-		 * thread_group + QoS. ie we try to give the reference back to the kqwl.
-		 * If we fail, that's because a higher QoS thread group was set on the
-		 * kqwl in kqueue_set_preadopted_thread_group in which case, we need to
-		 * go back to (1).
-		 */
-
-		_Atomic(struct thread_group *) * tg_loc = kqr_preadopt_thread_group_addr(req);
-
-		thread_group_qos_t old_tg, new_tg;
-		int ret = 0;
-again:
-		ret = os_atomic_rmw_loop(tg_loc, old_tg, new_tg, relaxed, {
-			if ((!KQWL_HAS_VALID_PREADOPTED_TG(old_tg)) ||
-			KQWL_HAS_PERMANENT_PREADOPTED_TG(old_tg)) {
-			        os_atomic_rmw_loop_give_up(break);
-			}
-
-			/*
-			 * Leave the QoS behind - kqueue_set_preadopted_thread_group will
-			 * only modify it if there is a higher QoS thread group to attach
-			 */
-			new_tg = (thread_group_qos_t) ((uintptr_t) old_tg & KQWL_PREADOPT_TG_QOS_MASK);
-		});
-
-		if (ret) {
-			/*
-			 * We successfully took the ref from the kqwl so set it on the
-			 * thread now
-			 */
-			thread_set_preadopt_thread_group(th, KQWL_GET_PREADOPTED_TG(old_tg));
-
-			thread_group_qos_t thread_group_to_expect = new_tg;
-			thread_group_qos_t thread_group_to_set = old_tg;
-
-			os_atomic_rmw_loop(tg_loc, old_tg, new_tg, relaxed, {
-				if (old_tg != thread_group_to_expect) {
-				        /*
-				         * There was an intervening write to the kqwl_preadopt_tg,
-				         * and it has a higher QoS than what we are working with
-				         * here. Abandon our current adopted thread group and redo
-				         * the full dance
-				         */
-				        thread_group_deallocate_safe(KQWL_GET_PREADOPTED_TG(thread_group_to_set));
-				        os_atomic_rmw_loop_give_up(goto again);
-				}
-
-				new_tg = thread_group_to_set;
-			});
-		} else {
-			if (KQWL_HAS_PERMANENT_PREADOPTED_TG(old_tg)) {
-				thread_set_preadopt_thread_group(th, KQWL_GET_PREADOPTED_TG(old_tg));
-			} else {
-				/* Nothing valid on the kqwl, just clear what's on the thread */
-				thread_set_preadopt_thread_group(th, NULL);
-			}
-		}
-	} else {
-		/* Not even a kqwl, clear what's on the thread */
-		thread_set_preadopt_thread_group(th, NULL);
-	}
-#endif
 	thread_set_workq_pri(th, qos, priority, policy);
 }
 
@@ -899,7 +675,7 @@
 	}
 	os_atomic_or(&wq->wq_flags, WQ_DEATH_CALL_SCHEDULED, relaxed);
 
-	WQ_TRACE_WQ(TRACE_wq_death_call | DBG_FUNC_NONE, wq, 1, 0, 0);
+	WQ_TRACE_WQ(TRACE_wq_death_call | DBG_FUNC_NONE, wq, 1, 0, 0, 0);
 
 	/*
 	 * <rdar://problem/13139182> Due to how long term timers work, the leeway
@@ -940,7 +716,7 @@
 
 	if (now - uth->uu_save.uus_workq_park_data.idle_stamp > delay) {
 		WQ_TRACE_WQ(TRACE_wq_thread_terminate | DBG_FUNC_START,
-		    wq, wq->wq_thidlecount, 0, 0);
+		    wq, wq->wq_thidlecount, 0, 0, 0);
 		wq->wq_thdying_count++;
 		uth->uu_workq_flags |= UT_WORKQ_DYING;
 		if ((uth->uu_workq_flags & UT_WORKQ_IDLE_CLEANUP) == 0) {
@@ -959,13 +735,11 @@
 	struct workqueue *wq = proc_get_wqptr_fast(p);
 
 	workq_lock_spin(wq);
-	if (!workq_thread_is_permanently_bound(uth)) {
-		TAILQ_REMOVE(&wq->wq_thrunlist, uth, uu_workq_entry);
-		if (uth->uu_workq_flags & UT_WORKQ_DYING) {
-			WQ_TRACE_WQ(TRACE_wq_thread_terminate | DBG_FUNC_END,
-			    wq, wq->wq_thidlecount, 0, 0);
-			workq_death_policy_evaluate(wq, 1);
-		}
+	TAILQ_REMOVE(&wq->wq_thrunlist, uth, uu_workq_entry);
+	if (uth->uu_workq_flags & UT_WORKQ_DYING) {
+		WQ_TRACE_WQ(TRACE_wq_thread_terminate | DBG_FUNC_END,
+		    wq, wq->wq_thidlecount, 0, 0, 0);
+		workq_death_policy_evaluate(wq, 1);
 	}
 	if (wq->wq_nthreads-- == wq_max_threads) {
 		/*
@@ -978,7 +752,7 @@
 	}
 	workq_unlock(wq);
 
-	thread_deallocate(get_machthread(uth));
+	thread_deallocate(uth->uu_thread);
 }
 
 static void
@@ -987,15 +761,15 @@
 	struct workqueue *wq = param0;
 
 	workq_lock_spin(wq);
-	WQ_TRACE_WQ(TRACE_wq_death_call | DBG_FUNC_START, wq, 0, 0, 0);
+	WQ_TRACE_WQ(TRACE_wq_death_call | DBG_FUNC_START, wq, 0, 0, 0, 0);
 	os_atomic_andnot(&wq->wq_flags, WQ_DEATH_CALL_SCHEDULED, relaxed);
 	workq_death_policy_evaluate(wq, 0);
-	WQ_TRACE_WQ(TRACE_wq_death_call | DBG_FUNC_END, wq, 0, 0, 0);
+	WQ_TRACE_WQ(TRACE_wq_death_call | DBG_FUNC_END, wq, 0, 0, 0, 0);
 	workq_unlock(wq);
 }
 
 static struct uthread *
-workq_pop_idle_thread(struct workqueue *wq, uint16_t uu_flags,
+workq_pop_idle_thread(struct workqueue *wq, uint8_t uu_flags,
     bool *needs_wakeup)
 {
 	struct uthread *uth;
@@ -1010,10 +784,6 @@
 
 	assert((uth->uu_workq_flags & UT_WORKQ_RUNNING) == 0);
 	uth->uu_workq_flags |= UT_WORKQ_RUNNING | uu_flags;
-
-	/* A thread is never woken up as part of the cooperative pool */
-	assert((uu_flags & UT_WORKQ_COOPERATIVE) == 0);
-
 	if ((uu_flags & UT_WORKQ_OVERCOMMIT) == 0) {
 		wq->wq_constrained_threads_scheduled++;
 	}
@@ -1061,13 +831,8 @@
  * - dropped and retaken around thread creation
  * - return with workq lock held
  */
-static kern_return_t
-workq_add_new_idle_thread(
-	proc_t             p,
-	struct workqueue  *wq,
-	thread_continue_t continuation,
-	bool              is_permanently_bound,
-	thread_t          *new_thread)
+static bool
+workq_add_new_idle_thread(proc_t p, struct workqueue *wq)
 {
 	mach_vm_offset_t th_stackaddr;
 	kern_return_t kret;
@@ -1077,22 +842,19 @@
 
 	workq_unlock(wq);
 
-	vm_map_t vmap = get_task_map(proc_task(p));
+	vm_map_t vmap = get_task_map(p->task);
 
 	kret = pthread_functions->workq_create_threadstack(p, vmap, &th_stackaddr);
 	if (kret != KERN_SUCCESS) {
 		WQ_TRACE_WQ(TRACE_wq_thread_create_failed | DBG_FUNC_NONE, wq,
-		    kret, 1, 0);
+		    kret, 1, 0, 0);
 		goto out;
 	}
 
-	kret = thread_create_workq_waiting(proc_task(p),
-	    continuation,
-	    &th,
-	    is_permanently_bound);
+	kret = thread_create_workq_waiting(p->task, workq_unpark_continue, &th);
 	if (kret != KERN_SUCCESS) {
 		WQ_TRACE_WQ(TRACE_wq_thread_create_failed | DBG_FUNC_NONE, wq,
-		    kret, 0, 0);
+		    kret, 0, 0, 0);
 		pthread_functions->workq_destroy_threadstack(p, vmap, th_stackaddr);
 		goto out;
 	}
@@ -1101,20 +863,14 @@
 	// on success, because it calls workq_thread_init_and_wq_lock() above
 
 	struct uthread *uth = get_bsdthread_info(th);
-	uth->uu_workq_stackaddr = (user_addr_t)th_stackaddr;
 
 	wq->wq_creations++;
-	if (!is_permanently_bound) {
-		wq->wq_thidlecount++;
-		TAILQ_INSERT_TAIL(&wq->wq_thnewlist, uth, uu_workq_entry);
-	}
-
-	if (new_thread) {
-		*new_thread = th;
-	}
-
-	WQ_TRACE_WQ(TRACE_wq_thread_create | DBG_FUNC_NONE, wq, 0, 0, 0);
-	return kret;
+	wq->wq_thidlecount++;
+	uth->uu_workq_stackaddr = th_stackaddr;
+	TAILQ_INSERT_TAIL(&wq->wq_thnewlist, uth, uu_workq_entry);
+
+	WQ_TRACE_WQ(TRACE_wq_thread_create | DBG_FUNC_NONE, wq, 0, 0, 0, 0);
+	return true;
 
 out:
 	workq_lock_spin(wq);
@@ -1124,41 +880,8 @@
 	 * to do so when it fails.
 	 */
 	wq->wq_nthreads--;
-	return kret;
-}
-
-static inline bool
-workq_thread_is_overcommit(struct uthread *uth)
-{
-	return (uth->uu_workq_flags & UT_WORKQ_OVERCOMMIT) != 0;
-}
-
-static inline bool
-workq_thread_is_nonovercommit(struct uthread *uth)
-{
-	return (uth->uu_workq_flags & (UT_WORKQ_OVERCOMMIT |
-	       UT_WORKQ_COOPERATIVE)) == 0;
-}
-
-static inline bool
-workq_thread_is_cooperative(struct uthread *uth)
-{
-	return (uth->uu_workq_flags & UT_WORKQ_COOPERATIVE) != 0;
-}
-
-bool
-workq_thread_is_permanently_bound(struct uthread *uth)
-{
-	return (uth->uu_workq_flags & UT_WORKQ_PERMANENT_BIND) != 0;
-}
-
-static inline void
-workq_thread_set_type(struct uthread *uth, uint16_t flags)
-{
-	uth->uu_workq_flags &= ~(UT_WORKQ_OVERCOMMIT | UT_WORKQ_COOPERATIVE);
-	uth->uu_workq_flags |= flags;
-}
-
+	return false;
+}
 
 #define WORKQ_UNPARK_FOR_DEATH_WAS_IDLE 0x1
 
@@ -1196,8 +919,8 @@
 	}
 
 	uint32_t flags = WQ_FLAG_THREAD_NEWSPI | qos | WQ_FLAG_THREAD_PRIO_QOS;
-	thread_t th = get_machthread(uth);
-	vm_map_t vmap = get_task_map(proc_task(p));
+	thread_t th = uth->uu_thread;
+	vm_map_t vmap = get_task_map(p->task);
 
 	if (!first_use) {
 		flags |= WQ_FLAG_THREAD_REUSE;
@@ -1249,36 +972,20 @@
 	uint64_t now = mach_absolute_time();
 	bool is_creator = (uth == wq->wq_creator);
 
-	if (workq_thread_is_cooperative(uth)) {
-		assert(!is_creator);
-
-		thread_qos_t thread_qos = uth->uu_workq_pri.qos_req;
-		_wq_cooperative_queue_scheduled_count_dec(wq, thread_qos);
-
-		/* Before we get here, we always go through
-		 * workq_select_threadreq_or_park_and_unlock. If we got here, it means
-		 * that we went through the logic in workq_threadreq_select which
-		 * did the refresh for the next best cooperative qos while
-		 * excluding the current thread - we shouldn't need to do it again.
-		 */
-		assert(_wq_cooperative_queue_refresh_best_req_qos(wq) == false);
-	} else if (workq_thread_is_nonovercommit(uth)) {
-		assert(!is_creator);
-
+	if ((uth->uu_workq_flags & UT_WORKQ_OVERCOMMIT) == 0) {
 		wq->wq_constrained_threads_scheduled--;
 	}
-
-	uth->uu_workq_flags &= ~(UT_WORKQ_RUNNING | UT_WORKQ_OVERCOMMIT | UT_WORKQ_COOPERATIVE);
+	uth->uu_workq_flags &= ~(UT_WORKQ_RUNNING | UT_WORKQ_OVERCOMMIT);
 	TAILQ_REMOVE(&wq->wq_thrunlist, uth, uu_workq_entry);
 	wq->wq_threads_scheduled--;
 
 	if (is_creator) {
 		wq->wq_creator = NULL;
 		WQ_TRACE_WQ(TRACE_wq_creator_select, wq, 3, 0,
-		    uth->uu_save.uus_workq_park_data.yields);
-	}
-
-	if (wq->wq_inheritor == get_machthread(uth)) {
+		    uth->uu_save.uus_workq_park_data.yields, 0);
+	}
+
+	if (wq->wq_inheritor == uth->uu_thread) {
 		assert(wq->wq_creator == NULL);
 		if (wq->wq_reqcount) {
 			workq_turnstile_update_inheritor(wq, wq, TURNSTILE_INHERITOR_WORKQ);
@@ -1323,7 +1030,7 @@
 		}
 
 		WQ_TRACE_WQ(TRACE_wq_thread_terminate | DBG_FUNC_START,
-		    wq, cur_idle, 0, 0);
+		    wq, cur_idle, 0, 0, 0);
 		wq->wq_thdying_count++;
 		uth->uu_workq_flags |= UT_WORKQ_DYING;
 		uth->uu_workq_flags &= ~UT_WORKQ_IDLE_CLEANUP;
@@ -1353,30 +1060,6 @@
 
 #pragma mark thread requests
 
-static inline bool
-workq_tr_is_overcommit(workq_tr_flags_t tr_flags)
-{
-	return (tr_flags & WORKQ_TR_FLAG_OVERCOMMIT) != 0;
-}
-
-static inline bool
-workq_tr_is_nonovercommit(workq_tr_flags_t tr_flags)
-{
-	return (tr_flags & (WORKQ_TR_FLAG_OVERCOMMIT |
-	       WORKQ_TR_FLAG_COOPERATIVE |
-	       WORKQ_TR_FLAG_PERMANENT_BIND)) == 0;
-}
-
-static inline bool
-workq_tr_is_cooperative(workq_tr_flags_t tr_flags)
-{
-	return (tr_flags & WORKQ_TR_FLAG_COOPERATIVE) != 0;
-}
-
-#define workq_threadreq_is_overcommit(req) workq_tr_is_overcommit((req)->tr_flags)
-#define workq_threadreq_is_nonovercommit(req) workq_tr_is_nonovercommit((req)->tr_flags)
-#define workq_threadreq_is_cooperative(req) workq_tr_is_cooperative((req)->tr_flags)
-
 static inline int
 workq_priority_for_req(workq_threadreq_t req)
 {
@@ -1390,239 +1073,21 @@
 	return thread_workq_pri_for_qos(qos);
 }
 
-static inline struct priority_queue_sched_max *
+static inline struct priority_queue *
 workq_priority_queue_for_req(struct workqueue *wq, workq_threadreq_t req)
 {
-	assert(!workq_tr_is_cooperative(req->tr_flags));
-
 	if (req->tr_flags & WORKQ_TR_FLAG_WL_OUTSIDE_QOS) {
 		return &wq->wq_special_queue;
-	} else if (workq_tr_is_overcommit(req->tr_flags)) {
+	} else if (req->tr_flags & WORKQ_TR_FLAG_OVERCOMMIT) {
 		return &wq->wq_overcommit_queue;
 	} else {
 		return &wq->wq_constrained_queue;
 	}
 }
 
-/* Calculates the number of threads scheduled >= the input QoS */
-static uint64_t
-workq_num_cooperative_threads_scheduled_to_qos_internal(struct workqueue *wq, thread_qos_t qos)
-{
-	uint64_t num_cooperative_threads = 0;
-
-	for (thread_qos_t cur_qos = WORKQ_THREAD_QOS_MAX; cur_qos >= qos; cur_qos--) {
-		uint8_t bucket = _wq_bucket(cur_qos);
-		num_cooperative_threads += wq->wq_cooperative_queue_scheduled_count[bucket];
-	}
-
-	return num_cooperative_threads;
-}
-
-/* Calculates the number of threads scheduled >= the input QoS */
-static uint64_t
-workq_num_cooperative_threads_scheduled_to_qos_locked(struct workqueue *wq, thread_qos_t qos)
-{
-	workq_lock_held(wq);
-	return workq_num_cooperative_threads_scheduled_to_qos_internal(wq, qos);
-}
-
-static uint64_t
-workq_num_cooperative_threads_scheduled_total(struct workqueue *wq)
-{
-	return workq_num_cooperative_threads_scheduled_to_qos_locked(wq, WORKQ_THREAD_QOS_MIN);
-}
-
-static bool
-workq_has_cooperative_thread_requests(struct workqueue *wq)
-{
-	for (thread_qos_t qos = WORKQ_THREAD_QOS_MAX; qos >= WORKQ_THREAD_QOS_MIN; qos--) {
-		uint8_t bucket = _wq_bucket(qos);
-		if (!STAILQ_EMPTY(&wq->wq_cooperative_queue[bucket])) {
-			return true;
-		}
-	}
-
-	return false;
-}
-
 /*
- * Determines the next QoS bucket we should service next in the cooperative
- * pool. This function will always return a QoS for cooperative pool as long as
- * there are requests to be serviced.
- *
- * Unlike the other thread pools, for the cooperative thread pool the schedule
- * counts for the various buckets in the pool affect the next best request for
- * it.
- *
- * This function is called in the following contexts:
- *
- * a) When determining the best thread QoS for cooperative bucket for the
- * creator/thread reuse
- *
- * b) Once (a) has happened and thread has bound to a thread request, figuring
- * out whether the next best request for this pool has changed so that creator
- * can be scheduled.
- *
- * Returns true if the cooperative queue's best qos changed from previous
- * value.
- */
-static bool
-_wq_cooperative_queue_refresh_best_req_qos(struct workqueue *wq)
-{
-	workq_lock_held(wq);
-
-	thread_qos_t old_best_req_qos = wq->wq_cooperative_queue_best_req_qos;
-
-	/* We determine the next best cooperative thread request based on the
-	 * following:
-	 *
-	 * 1. Take the MAX of the following:
-	 *		a) Highest qos with pending TRs such that number of scheduled
-	 *		threads so far with >= qos is < wq_max_cooperative_threads
-	 *		b) Highest qos bucket with pending TRs but no scheduled threads for that bucket
-	 *
-	 * 2. If the result of (1) is UN, then we pick the highest priority amongst
-	 * pending thread requests in the pool.
-	 *
-	 */
-	thread_qos_t highest_qos_with_no_scheduled = THREAD_QOS_UNSPECIFIED;
-	thread_qos_t highest_qos_req_with_width = THREAD_QOS_UNSPECIFIED;
-
-	thread_qos_t highest_qos_req = THREAD_QOS_UNSPECIFIED;
-
-	int scheduled_count_till_qos = 0;
-
-	for (thread_qos_t qos = WORKQ_THREAD_QOS_MAX; qos >= WORKQ_THREAD_QOS_MIN; qos--) {
-		uint8_t bucket = _wq_bucket(qos);
-		uint8_t scheduled_count_for_bucket = wq->wq_cooperative_queue_scheduled_count[bucket];
-		scheduled_count_till_qos += scheduled_count_for_bucket;
-
-		if (!STAILQ_EMPTY(&wq->wq_cooperative_queue[bucket])) {
-			if (qos > highest_qos_req) {
-				highest_qos_req = qos;
-			}
-			/*
-			 * The pool isn't saturated for threads at and above this QoS, and
-			 * this qos bucket has pending requests
-			 */
-			if (scheduled_count_till_qos < wq_cooperative_queue_max_size(wq)) {
-				if (qos > highest_qos_req_with_width) {
-					highest_qos_req_with_width = qos;
-				}
-			}
-
-			/*
-			 * There are no threads scheduled for this bucket but there
-			 * is work pending, give it at least 1 thread
-			 */
-			if (scheduled_count_for_bucket == 0) {
-				if (qos > highest_qos_with_no_scheduled) {
-					highest_qos_with_no_scheduled = qos;
-				}
-			}
-		}
-	}
-
-	wq->wq_cooperative_queue_best_req_qos = MAX(highest_qos_with_no_scheduled, highest_qos_req_with_width);
-	if (wq->wq_cooperative_queue_best_req_qos == THREAD_QOS_UNSPECIFIED) {
-		wq->wq_cooperative_queue_best_req_qos = highest_qos_req;
-	}
-
-#if MACH_ASSERT
-	/* Assert that if we are showing up the next best req as UN, then there
-	 * actually is no thread request in the cooperative pool buckets */
-	if (wq->wq_cooperative_queue_best_req_qos == THREAD_QOS_UNSPECIFIED) {
-		assert(!workq_has_cooperative_thread_requests(wq));
-	}
-#endif
-
-	return old_best_req_qos != wq->wq_cooperative_queue_best_req_qos;
-}
-
-/*
- * Returns whether or not the input thread (or creator thread if uth is NULL)
- * should be allowed to work as part of the cooperative pool for the <input qos>
- * bucket.
- *
- * This function is called in a bunch of places:
- *		a) Quantum expires for a thread and it is part of the cooperative pool
- *		b) When trying to pick a thread request for the creator thread to
- *		represent.
- *		c) When a thread is trying to pick a thread request to actually bind to
- *		and service.
- *
- * Called with workq lock held.
- */
-
-#define WQ_COOPERATIVE_POOL_UNSATURATED 1
-#define WQ_COOPERATIVE_BUCKET_UNSERVICED 2
-#define WQ_COOPERATIVE_POOL_SATURATED_UP_TO_QOS 3
-
-static bool
-workq_cooperative_allowance(struct workqueue *wq, thread_qos_t qos, struct uthread *uth,
-    bool may_start_timer)
-{
-	workq_lock_held(wq);
-
-	bool exclude_thread_as_scheduled = false;
-	bool passed_admissions = false;
-	uint8_t bucket = _wq_bucket(qos);
-
-	if (uth && workq_thread_is_cooperative(uth)) {
-		exclude_thread_as_scheduled = true;
-		_wq_cooperative_queue_scheduled_count_dec(wq, uth->uu_workq_pri.qos_req);
-	}
-
-	/*
-	 * We have not saturated the pool yet, let this thread continue
-	 */
-	uint64_t total_cooperative_threads;
-	total_cooperative_threads = workq_num_cooperative_threads_scheduled_total(wq);
-	if (total_cooperative_threads < wq_cooperative_queue_max_size(wq)) {
-		passed_admissions = true;
-		WQ_TRACE(TRACE_wq_cooperative_admission | DBG_FUNC_NONE,
-		    total_cooperative_threads, qos, passed_admissions,
-		    WQ_COOPERATIVE_POOL_UNSATURATED);
-		goto out;
-	}
-
-	/*
-	 * Without this thread, nothing is servicing the bucket which has pending
-	 * work
-	 */
-	uint64_t bucket_scheduled = wq->wq_cooperative_queue_scheduled_count[bucket];
-	if (bucket_scheduled == 0 &&
-	    !STAILQ_EMPTY(&wq->wq_cooperative_queue[bucket])) {
-		passed_admissions = true;
-		WQ_TRACE(TRACE_wq_cooperative_admission | DBG_FUNC_NONE,
-		    total_cooperative_threads, qos, passed_admissions,
-		    WQ_COOPERATIVE_BUCKET_UNSERVICED);
-		goto out;
-	}
-
-	/*
-	 * If number of threads at the QoS bucket >= input QoS exceeds the max we want
-	 * for the pool, deny this thread
-	 */
-	uint64_t aggregate_down_to_qos = workq_num_cooperative_threads_scheduled_to_qos_locked(wq, qos);
-	passed_admissions = (aggregate_down_to_qos < wq_cooperative_queue_max_size(wq));
-	WQ_TRACE(TRACE_wq_cooperative_admission | DBG_FUNC_NONE, aggregate_down_to_qos,
-	    qos, passed_admissions, WQ_COOPERATIVE_POOL_SATURATED_UP_TO_QOS);
-
-	if (!passed_admissions && may_start_timer) {
-		workq_schedule_delayed_thread_creation(wq, 0);
-	}
-
-out:
-	if (exclude_thread_as_scheduled) {
-		_wq_cooperative_queue_scheduled_count_inc(wq, uth->uu_workq_pri.qos_req);
-	}
-	return passed_admissions;
-}
-
-/*
- * returns true if the best request for the pool changed as a result of
- * enqueuing this thread request.
+ * returns true if the the enqueued request is the highest priority item
+ * in its priority queue.
  */
 static bool
 workq_threadreq_enqueue(struct workqueue *wq, workq_threadreq_t req)
@@ -1639,24 +1104,10 @@
 		wq->wq_event_manager_threadreq = req;
 		return true;
 	}
-
-	if (workq_threadreq_is_cooperative(req)) {
-		assert(req->tr_qos != WORKQ_THREAD_QOS_MANAGER);
-		assert(req->tr_qos != WORKQ_THREAD_QOS_ABOVEUI);
-
-		struct workq_threadreq_tailq *bucket = &wq->wq_cooperative_queue[_wq_bucket(req->tr_qos)];
-		STAILQ_INSERT_TAIL(bucket, req, tr_link);
-
-		return _wq_cooperative_queue_refresh_best_req_qos(wq);
-	}
-
-	struct priority_queue_sched_max *q = workq_priority_queue_for_req(wq, req);
-
-	priority_queue_entry_set_sched_pri(q, &req->tr_entry,
-	    workq_priority_for_req(req), false);
-
-	if (priority_queue_insert(q, &req->tr_entry)) {
-		if (workq_threadreq_is_nonovercommit(req)) {
+	if (priority_queue_insert(workq_priority_queue_for_req(wq, req),
+	    &req->tr_entry, workq_priority_for_req(req),
+	    PRIORITY_QUEUE_SCHED_PRI_MAX_HEAP_COMPARE)) {
+		if ((req->tr_flags & WORKQ_TR_FLAG_OVERCOMMIT) == 0) {
 			_wq_thactive_refresh_best_constrained_req_qos(wq);
 		}
 		return true;
@@ -1665,91 +1116,30 @@
 }
 
 /*
- * returns true if one of the following is true (so as to update creator if
- * needed):
- *
- * (a) the next highest request of the pool we dequeued the request from changed
- * (b) the next highest requests of the pool the current thread used to be a
- * part of, changed
- *
- * For overcommit, special and constrained pools, the next highest QoS for each
- * pool just a MAX of pending requests so tracking (a) is sufficient.
- *
- * But for cooperative thread pool, the next highest QoS for the pool depends on
- * schedule counts in the pool as well. So if the current thread used to be
- * cooperative in it's previous logical run ie (b), then that can also affect
- * cooperative pool's next best QoS requests.
+ * returns true if the the dequeued request was the highest priority item
+ * in its priority queue.
  */
 static bool
-workq_threadreq_dequeue(struct workqueue *wq, workq_threadreq_t req,
-    bool cooperative_sched_count_changed)
+workq_threadreq_dequeue(struct workqueue *wq, workq_threadreq_t req)
 {
 	wq->wq_reqcount--;
-
-	bool next_highest_request_changed = false;
 
 	if (--req->tr_count == 0) {
 		if (req->tr_qos == WORKQ_THREAD_QOS_MANAGER) {
 			assert(wq->wq_event_manager_threadreq == req);
 			assert(req->tr_count == 0);
 			wq->wq_event_manager_threadreq = NULL;
-
-			/* If a cooperative thread was the one which picked up the manager
-			 * thread request, we need to reevaluate the cooperative pool
-			 * anyways.
-			 */
-			if (cooperative_sched_count_changed) {
-				_wq_cooperative_queue_refresh_best_req_qos(wq);
+			return true;
+		}
+		if (priority_queue_remove(workq_priority_queue_for_req(wq, req),
+		    &req->tr_entry, PRIORITY_QUEUE_SCHED_PRI_MAX_HEAP_COMPARE)) {
+			if ((req->tr_flags & WORKQ_TR_FLAG_OVERCOMMIT) == 0) {
+				_wq_thactive_refresh_best_constrained_req_qos(wq);
 			}
 			return true;
 		}
-
-		if (workq_threadreq_is_cooperative(req)) {
-			assert(req->tr_qos != WORKQ_THREAD_QOS_MANAGER);
-			assert(req->tr_qos != WORKQ_THREAD_QOS_ABOVEUI);
-			/* Account for the fact that BG and MT are coalesced when
-			 * calculating best request for cooperative pool
-			 */
-			assert(_wq_bucket(req->tr_qos) == _wq_bucket(wq->wq_cooperative_queue_best_req_qos));
-
-			struct workq_threadreq_tailq *bucket = &wq->wq_cooperative_queue[_wq_bucket(req->tr_qos)];
-			__assert_only workq_threadreq_t head = STAILQ_FIRST(bucket);
-
-			assert(head == req);
-			STAILQ_REMOVE_HEAD(bucket, tr_link);
-
-			/*
-			 * If the request we're dequeueing is cooperative, then the sched
-			 * counts definitely changed.
-			 */
-			assert(cooperative_sched_count_changed);
-		}
-
-		/*
-		 * We want to do the cooperative pool refresh after dequeueing a
-		 * cooperative thread request if any (to combine both effects into 1
-		 * refresh operation)
-		 */
-		if (cooperative_sched_count_changed) {
-			next_highest_request_changed = _wq_cooperative_queue_refresh_best_req_qos(wq);
-		}
-
-		if (!workq_threadreq_is_cooperative(req)) {
-			/*
-			 * All other types of requests are enqueued in priority queues
-			 */
-
-			if (priority_queue_remove(workq_priority_queue_for_req(wq, req),
-			    &req->tr_entry)) {
-				next_highest_request_changed |= true;
-				if (workq_threadreq_is_nonovercommit(req)) {
-					_wq_thactive_refresh_best_constrained_req_qos(wq);
-				}
-			}
-		}
-	}
-
-	return next_highest_request_changed;
+	}
+	return false;
 }
 
 static void
@@ -1805,17 +1195,17 @@
 	} else if (now - wq->wq_thread_call_last_run <= wq->wq_timer_interval) {
 		wq->wq_timer_interval *= 2;
 		if (wq->wq_timer_interval > wq_max_timer_interval.abstime) {
-			wq->wq_timer_interval = (uint32_t)wq_max_timer_interval.abstime;
+			wq->wq_timer_interval = wq_max_timer_interval.abstime;
 		}
 	} else if (now - wq->wq_thread_call_last_run > 2 * wq->wq_timer_interval) {
 		wq->wq_timer_interval /= 2;
 		if (wq->wq_timer_interval < wq_stalled_window.abstime) {
-			wq->wq_timer_interval = (uint32_t)wq_stalled_window.abstime;
+			wq->wq_timer_interval = wq_stalled_window.abstime;
 		}
 	}
 
 	WQ_TRACE_WQ(TRACE_wq_start_add_timer, wq, wq->wq_reqcount,
-	    _wq_flags(wq), wq->wq_timer_interval);
+	    _wq_flags(wq), wq->wq_timer_interval, 0);
 
 	thread_call_t call = wq->wq_delayed_call;
 	uintptr_t arg = WQ_DELAYED_CALL_SCHEDULED;
@@ -1834,7 +1224,7 @@
 	if (workq_thread_call_prepost(wq, WQ_IMMEDIATE_CALL_SCHEDULED,
 	    WQ_IMMEDIATE_CALL_PENDED, 0)) {
 		WQ_TRACE_WQ(TRACE_wq_start_add_timer, wq, wq->wq_reqcount,
-		    _wq_flags(wq), 0);
+		    _wq_flags(wq), 0, 0);
 
 		uintptr_t arg = WQ_IMMEDIATE_CALL_SCHEDULED;
 		if (thread_call_enter1(wq->wq_immediate_call, (void *)arg)) {
@@ -1918,7 +1308,7 @@
 	    (my_flag == WQ_IMMEDIATE_CALL_SCHEDULED));
 
 	WQ_TRACE_WQ(TRACE_wq_add_timer | DBG_FUNC_START, wq, _wq_flags(wq),
-	    wq->wq_nthreads, wq->wq_thidlecount);
+	    wq->wq_nthreads, wq->wq_thidlecount, 0);
 
 	workq_lock_spin(wq);
 
@@ -1931,7 +1321,7 @@
 	workq_unlock(wq);
 
 	WQ_TRACE_WQ(TRACE_wq_add_timer | DBG_FUNC_END, wq, 0,
-	    wq->wq_nthreads, wq->wq_thidlecount);
+	    wq->wq_nthreads, wq->wq_thidlecount, 0);
 }
 
 #pragma mark thread state tracking
@@ -1939,9 +1329,9 @@
 static void
 workq_sched_callback(int type, thread_t thread)
 {
-	thread_ro_t tro = get_thread_ro(thread);
 	struct uthread *uth = get_bsdthread_info(thread);
-	struct workqueue *wq = proc_get_wqptr(tro->tro_proc);
+	proc_t proc = get_bsdtask_info(get_threadtask(thread));
+	struct workqueue *wq = proc_get_wqptr(proc);
 	thread_qos_t req_qos, qos = uth->uu_workq_pri.qos_bucket;
 	wq_thactive_t old_thactive;
 	bool start_timer = false;
@@ -2003,7 +1393,7 @@
 			    old_thactive, qos, NULL, NULL);
 			WQ_TRACE_WQ(TRACE_wq_thread_block | DBG_FUNC_START, wq,
 			    old - 1, qos | (req_qos << 8),
-			    wq->wq_reqcount << 1 | start_timer);
+			    wq->wq_reqcount << 1 | start_timer, 0);
 		}
 		break;
 
@@ -2023,7 +1413,7 @@
 			req_qos = WQ_THACTIVE_BEST_CONSTRAINED_REQ_QOS(old_thactive);
 			WQ_TRACE_WQ(TRACE_wq_thread_block | DBG_FUNC_END, wq,
 			    old + 1, qos | (req_qos << 8),
-			    wq->wq_threads_scheduled);
+			    wq->wq_threads_scheduled, 0);
 		}
 		break;
 	}
@@ -2052,7 +1442,7 @@
 	turnstile_cleanup();
 	turnstile_deallocate(ts);
 
-	lck_ticket_destroy(&wq->wq_lock, &workq_lck_grp);
+	lck_spin_destroy(&wq->wq_lock, workq_lck_grp);
 	zfree(workq_zone_workqueue, wq);
 }
 
@@ -2089,7 +1479,7 @@
 	}
 
 	if (wq_init_constrained_limit) {
-		uint32_t limit, num_cpus = ml_wait_max_cpus();
+		uint32_t limit, num_cpus = ml_get_max_cpus();
 
 		/*
 		 * set up the limit for the constrained pool
@@ -2115,8 +1505,6 @@
 			wq_max_parallelism[_wq_bucket(qos)] =
 			    qos_max_parallelism(qos, QOS_PARALLELISM_COUNT_LOGICAL);
 		}
-
-		wq_max_cooperative_threads = num_cpus;
 
 		wq_init_constrained_limit = 0;
 	}
@@ -2127,7 +1515,8 @@
 			goto out;
 		}
 
-		wq = zalloc_flags(workq_zone_workqueue, Z_WAITOK | Z_ZERO);
+		wq = (struct workqueue *)zalloc(workq_zone_workqueue);
+		bzero(wq, sizeof(struct workqueue));
 
 		os_ref_init_count(&wq->wq_refcnt, &workq_refgrp, 1);
 
@@ -2135,7 +1524,7 @@
 		thread_qos_t mgr_priority_hint = task_get_default_manager_qos(current_task());
 		pthread_priority_t pp = _pthread_priority_make_from_thread_qos(mgr_priority_hint, 0, 0);
 		wq->wq_event_manager_priority = (uint32_t)pp;
-		wq->wq_timer_interval = (uint32_t)wq_stalled_window.abstime;
+		wq->wq_timer_interval = wq_stalled_window.abstime;
 		wq->wq_proc = p;
 		turnstile_prepare((uintptr_t)wq, &wq->wq_turnstile, turnstile_alloc(),
 		    TURNSTILE_WORKQS);
@@ -2143,19 +1532,15 @@
 		TAILQ_INIT(&wq->wq_thrunlist);
 		TAILQ_INIT(&wq->wq_thnewlist);
 		TAILQ_INIT(&wq->wq_thidlelist);
-		priority_queue_init(&wq->wq_overcommit_queue);
-		priority_queue_init(&wq->wq_constrained_queue);
-		priority_queue_init(&wq->wq_special_queue);
-		for (int bucket = 0; bucket < WORKQ_NUM_QOS_BUCKETS; bucket++) {
-			STAILQ_INIT(&wq->wq_cooperative_queue[bucket]);
-		}
-
-		/* We are only using the delayed thread call for the constrained pool
-		 * which can't have work at >= UI QoS and so we can be fine with a
-		 * UI QoS thread call.
-		 */
-		wq->wq_delayed_call = thread_call_allocate_with_qos(
-			workq_add_new_threads_call, p, THREAD_QOS_USER_INTERACTIVE,
+		priority_queue_init(&wq->wq_overcommit_queue,
+		    PRIORITY_QUEUE_BUILTIN_MAX_HEAP);
+		priority_queue_init(&wq->wq_constrained_queue,
+		    PRIORITY_QUEUE_BUILTIN_MAX_HEAP);
+		priority_queue_init(&wq->wq_special_queue,
+		    PRIORITY_QUEUE_BUILTIN_MAX_HEAP);
+
+		wq->wq_delayed_call = thread_call_allocate_with_options(
+			workq_add_new_threads_call, p, THREAD_CALL_PRIORITY_KERNEL,
 			THREAD_CALL_OPTIONS_ONCE);
 		wq->wq_immediate_call = thread_call_allocate_with_options(
 			workq_add_new_threads_call, p, THREAD_CALL_PRIORITY_KERNEL,
@@ -2164,10 +1549,10 @@
 			workq_kill_old_threads_call, wq,
 			THREAD_CALL_PRIORITY_USER, THREAD_CALL_OPTIONS_ONCE);
 
-		lck_ticket_init(&wq->wq_lock, &workq_lck_grp);
+		lck_spin_init(&wq->wq_lock, workq_lck_grp, workq_lck_attr);
 
 		WQ_TRACE_WQ(TRACE_wq_create | DBG_FUNC_NONE, wq,
-		    VM_KERNEL_ADDRHIDE(wq), 0, 0);
+		    VM_KERNEL_ADDRHIDE(wq), 0, 0, 0);
 		proc_set_wqptr(p, wq);
 	}
 out:
@@ -2194,7 +1579,7 @@
 		return;
 	}
 
-	WQ_TRACE_WQ(TRACE_wq_pthread_exit | DBG_FUNC_START, wq, 0, 0, 0);
+	WQ_TRACE_WQ(TRACE_wq_pthread_exit | DBG_FUNC_START, wq, 0, 0, 0, 0);
 
 	workq_lock_spin(wq);
 
@@ -2233,19 +1618,19 @@
 	 * It is hence safe to do the tear down without holding any lock.
 	 */
 	priority_queue_destroy(&wq->wq_overcommit_queue,
-	    struct workq_threadreq_s, tr_entry, ^(workq_threadreq_t e){
+	    struct workq_threadreq_s, tr_entry, ^(void *e){
 		workq_threadreq_destroy(p, e);
 	});
 	priority_queue_destroy(&wq->wq_constrained_queue,
-	    struct workq_threadreq_s, tr_entry, ^(workq_threadreq_t e){
+	    struct workq_threadreq_s, tr_entry, ^(void *e){
 		workq_threadreq_destroy(p, e);
 	});
 	priority_queue_destroy(&wq->wq_special_queue,
-	    struct workq_threadreq_s, tr_entry, ^(workq_threadreq_t e){
+	    struct workq_threadreq_s, tr_entry, ^(void *e){
 		workq_threadreq_destroy(p, e);
 	});
 
-	WQ_TRACE(TRACE_wq_pthread_exit | DBG_FUNC_END, 0, 0, 0, 0);
+	WQ_TRACE(TRACE_wq_pthread_exit | DBG_FUNC_END, 0, 0, 0, 0, 0);
 }
 
 /*
@@ -2267,7 +1652,7 @@
 	if (wq != NULL) {
 		thread_t th = current_thread();
 
-		WQ_TRACE_WQ(TRACE_wq_workqueue_exit | DBG_FUNC_START, wq, 0, 0, 0);
+		WQ_TRACE_WQ(TRACE_wq_workqueue_exit | DBG_FUNC_START, wq, 0, 0, 0, 0);
 
 		if (thread_get_tag(th) & THREAD_TAG_WORKQUEUE) {
 			/*
@@ -2300,32 +1685,23 @@
 		 * idle/new threads should have been interrupted and died on their own
 		 */
 		TAILQ_FOREACH_SAFE(uth, &wq->wq_thrunlist, uu_workq_entry, tmp) {
-			thread_t mth = get_machthread(uth);
-			thread_sched_call(mth, NULL);
-			thread_deallocate(mth);
+			thread_sched_call(uth->uu_thread, NULL);
+			thread_deallocate(uth->uu_thread);
 		}
 		assert(TAILQ_EMPTY(&wq->wq_thnewlist));
 		assert(TAILQ_EMPTY(&wq->wq_thidlelist));
 
 		WQ_TRACE_WQ(TRACE_wq_destroy | DBG_FUNC_END, wq,
-		    VM_KERNEL_ADDRHIDE(wq), 0, 0);
+		    VM_KERNEL_ADDRHIDE(wq), 0, 0, 0);
 
 		workq_deallocate(wq);
 
-		WQ_TRACE(TRACE_wq_workqueue_exit | DBG_FUNC_END, 0, 0, 0, 0);
+		WQ_TRACE(TRACE_wq_workqueue_exit | DBG_FUNC_END, 0, 0, 0, 0, 0);
 	}
 }
 
 
 #pragma mark bsd thread control
-
-bool
-bsdthread_part_of_cooperative_workqueue(struct uthread *uth)
-{
-	return (workq_thread_is_cooperative(uth) || workq_thread_is_nonovercommit(uth)) &&
-	       (uth->uu_workq_pri.qos_bucket != WORKQ_THREAD_QOS_MANAGER) &&
-	       (!workq_thread_is_permanently_bound(uth));
-}
 
 static bool
 _pthread_priority_to_policy(pthread_priority_t priority,
@@ -2351,7 +1727,6 @@
 	int unbind_rv = 0, qos_rv = 0, voucher_rv = 0, fixedpri_rv = 0;
 	bool is_wq_thread = (thread_get_tag(th) & THREAD_TAG_WORKQUEUE);
 
-	assert(th == current_thread());
 	if (flags & WORKQ_SET_SELF_WQ_KEVENT_UNBIND) {
 		if (!is_wq_thread) {
 			unbind_rv = EINVAL;
@@ -2378,38 +1753,12 @@
 	}
 
 qos:
-	if (flags & (WORKQ_SET_SELF_QOS_FLAG | WORKQ_SET_SELF_QOS_OVERRIDE_FLAG)) {
-		assert(flags & WORKQ_SET_SELF_QOS_FLAG);
-
+	if (flags & WORKQ_SET_SELF_QOS_FLAG) {
 		thread_qos_policy_data_t new_policy;
-		thread_qos_t qos_override = THREAD_QOS_UNSPECIFIED;
 
 		if (!_pthread_priority_to_policy(priority, &new_policy)) {
 			qos_rv = EINVAL;
 			goto voucher;
-		}
-
-		if (flags & WORKQ_SET_SELF_QOS_OVERRIDE_FLAG) {
-			/*
-			 * If the WORKQ_SET_SELF_QOS_OVERRIDE_FLAG is set, we definitely
-			 * should have an override QoS in the pthread_priority_t and we should
-			 * only come into this path for cooperative thread requests
-			 */
-			if (!_pthread_priority_has_override_qos(priority) ||
-			    !_pthread_priority_is_cooperative(priority)) {
-				qos_rv = EINVAL;
-				goto voucher;
-			}
-			qos_override = _pthread_priority_thread_override_qos(priority);
-		} else {
-			/*
-			 * If the WORKQ_SET_SELF_QOS_OVERRIDE_FLAG is not set, we definitely
-			 * should not have an override QoS in the pthread_priority_t
-			 */
-			if (_pthread_priority_has_override_qos(priority)) {
-				qos_rv = EINVAL;
-				goto voucher;
-			}
 		}
 
 		if (!is_wq_thread) {
@@ -2431,103 +1780,28 @@
 			/*
 			 * For workqueue threads, possibly adjust buckets and redrive thread
 			 * requests.
-			 *
-			 * Transitions allowed:
-			 *
-			 * overcommit --> non-overcommit
-			 * overcommit --> overcommit
-			 * non-overcommit --> non-overcommit
-			 * non-overcommit --> overcommit (to be deprecated later)
-			 * cooperative --> cooperative
-			 *
-			 * All other transitions aren't allowed so reject them.
 			 */
-			if (workq_thread_is_overcommit(uth) && _pthread_priority_is_cooperative(priority)) {
-				qos_rv = EINVAL;
-				goto voucher;
-			} else if (workq_thread_is_cooperative(uth) && !_pthread_priority_is_cooperative(priority)) {
-				qos_rv = EINVAL;
-				goto voucher;
-			} else if (workq_thread_is_nonovercommit(uth) && _pthread_priority_is_cooperative(priority)) {
-				qos_rv = EINVAL;
-				goto voucher;
-			}
-
+			bool old_overcommit = uth->uu_workq_flags & UT_WORKQ_OVERCOMMIT;
+			bool new_overcommit = priority & _PTHREAD_PRIORITY_OVERCOMMIT_FLAG;
 			struct uu_workq_policy old_pri, new_pri;
 			bool force_run = false;
 
-			if (qos_override) {
-				/*
-				 * We're in the case of a thread clarifying that it is for eg. not IN
-				 * req QoS but rather, UT req QoS with IN override. However, this can
-				 * race with a concurrent override happening to the thread via
-				 * workq_thread_add_dispatch_override so this needs to be
-				 * synchronized with the thread mutex.
-				 */
-				thread_mtx_lock(th);
+			workq_lock_spin(wq);
+
+			if (old_overcommit != new_overcommit) {
+				uth->uu_workq_flags ^= UT_WORKQ_OVERCOMMIT;
+				if (old_overcommit) {
+					wq->wq_constrained_threads_scheduled++;
+				} else if (wq->wq_constrained_threads_scheduled-- ==
+				    wq_max_constrained_threads) {
+					force_run = true;
+				}
 			}
 
-			workq_lock_spin(wq);
-
 			old_pri = new_pri = uth->uu_workq_pri;
-			new_pri.qos_req = (thread_qos_t)new_policy.qos_tier;
-
-			if (old_pri.qos_override < qos_override) {
-				/*
-				 * Since this can race with a concurrent override via
-				 * workq_thread_add_dispatch_override, only adjust override value if we
-				 * are higher - this is a saturating function.
-				 *
-				 * We should not be changing the final override values, we should simply
-				 * be redistributing the current value with a different breakdown of req
-				 * vs override QoS - assert to that effect. Therefore, buckets should
-				 * not change.
-				 */
-				new_pri.qos_override = qos_override;
-				assert(workq_pri_override(new_pri) == workq_pri_override(old_pri));
-				assert(workq_pri_bucket(new_pri) == workq_pri_bucket(old_pri));
-			}
-
-			/* Adjust schedule counts for various types of transitions */
-
-			/* overcommit -> non-overcommit */
-			if (workq_thread_is_overcommit(uth) && _pthread_priority_is_nonovercommit(priority)) {
-				workq_thread_set_type(uth, 0);
-				wq->wq_constrained_threads_scheduled++;
-
-				/* non-overcommit -> overcommit */
-			} else if (workq_thread_is_nonovercommit(uth) && _pthread_priority_is_overcommit(priority)) {
-				workq_thread_set_type(uth, UT_WORKQ_OVERCOMMIT);
-				force_run = (wq->wq_constrained_threads_scheduled-- == wq_max_constrained_threads);
-
-				/* cooperative -> cooperative */
-			} else if (workq_thread_is_cooperative(uth)) {
-				_wq_cooperative_queue_scheduled_count_dec(wq, old_pri.qos_req);
-				_wq_cooperative_queue_scheduled_count_inc(wq, new_pri.qos_req);
-
-				/* We're changing schedule counts within cooperative pool, we
-				 * need to refresh best cooperative QoS logic again */
-				force_run = _wq_cooperative_queue_refresh_best_req_qos(wq);
-			}
-
-			/*
-			 * This will set up an override on the thread if any and will also call
-			 * schedule_creator if needed
-			 */
+			new_pri.qos_req = new_policy.qos_tier;
 			workq_thread_update_bucket(p, wq, uth, old_pri, new_pri, force_run);
 			workq_unlock(wq);
-
-			if (qos_override) {
-				thread_mtx_unlock(th);
-			}
-
-			if (workq_thread_is_overcommit(uth)) {
-				thread_disarm_workqueue_quantum(th);
-			} else {
-				/* If the thread changed QoS buckets, the quantum duration
-				 * may have changed too */
-				thread_arm_workqueue_quantum(th);
-			}
 		}
 
 		kr = thread_policy_set_internal(th, THREAD_QOS_POLICY,
@@ -2582,6 +1856,7 @@
 		}
 	}
 
+
 done:
 	if (qos_rv && voucher_rv) {
 		/* Both failed, give that a unique error. */
@@ -2604,7 +1879,6 @@
 		return fixedpri_rv;
 	}
 
-
 	return 0;
 }
 
@@ -2618,12 +1892,12 @@
 	}
 
 	thread_t th = port_name_to_thread(kport,
-	    PORT_INTRANS_THREAD_IN_CURRENT_TASK);
+	    PORT_TO_THREAD_IN_CURRENT_TASK);
 	if (th == THREAD_NULL) {
 		return ESRCH;
 	}
 
-	int rv = proc_thread_qos_add_override(proc_task(p), th, 0, qos, TRUE,
+	int rv = proc_thread_qos_add_override(p->task, th, 0, qos, TRUE,
 	    resource, THREAD_QOS_OVERRIDE_TYPE_PTHREAD_EXPLICIT_OVERRIDE);
 
 	thread_deallocate(th);
@@ -2635,12 +1909,12 @@
     user_addr_t resource)
 {
 	thread_t th = port_name_to_thread(kport,
-	    PORT_INTRANS_THREAD_IN_CURRENT_TASK);
+	    PORT_TO_THREAD_IN_CURRENT_TASK);
 	if (th == THREAD_NULL) {
 		return ESRCH;
 	}
 
-	int rv = proc_thread_qos_remove_override(proc_task(p), th, 0, resource,
+	int rv = proc_thread_qos_remove_override(p->task, th, 0, resource,
 	    THREAD_QOS_OVERRIDE_TYPE_PTHREAD_EXPLICIT_OVERRIDE);
 
 	thread_deallocate(th);
@@ -2660,7 +1934,7 @@
 	}
 
 	thread_t thread = port_name_to_thread(kport,
-	    PORT_INTRANS_THREAD_IN_CURRENT_TASK);
+	    PORT_TO_THREAD_IN_CURRENT_TASK);
 	if (thread == THREAD_NULL) {
 		return ESRCH;
 	}
@@ -2672,16 +1946,20 @@
 	}
 
 	WQ_TRACE_WQ(TRACE_wq_override_dispatch | DBG_FUNC_NONE,
-	    wq, thread_tid(thread), 1, pp);
+	    wq, thread_tid(thread), 1, pp, 0);
 
 	thread_mtx_lock(thread);
 
 	if (ulock_addr) {
 		uint32_t val;
 		int rc;
-		vm_fault_disable();
+		/*
+		 * Workaround lack of explicit support for 'no-fault copyin'
+		 * <rdar://problem/24999882>, as disabling preemption prevents paging in
+		 */
+		disable_preemption();
 		rc = copyin_atomic32(ulock_addr, &val);
-		vm_fault_enable();
+		enable_preemption();
 		if (rc == 0 && ulock_owner_value_to_port_name(val) != kport) {
 			goto out;
 		}
@@ -2722,22 +2000,13 @@
 		return EPERM;
 	}
 
-	WQ_TRACE_WQ(TRACE_wq_override_reset | DBG_FUNC_NONE, wq, 0, 0, 0);
-
-	/*
-	 * workq_thread_add_dispatch_override takes the thread mutex before doing the
-	 * copyin to validate the drainer and apply the override. We need to do the
-	 * same here. See rdar://84472518
-	 */
-	thread_mtx_lock(thread);
+	WQ_TRACE_WQ(TRACE_wq_override_reset | DBG_FUNC_NONE, wq, 0, 0, 0, 0);
 
 	workq_lock_spin(wq);
 	old_pri = new_pri = uth->uu_workq_pri;
 	new_pri.qos_override = THREAD_QOS_UNSPECIFIED;
 	workq_thread_update_bucket(p, wq, uth, old_pri, new_pri, false);
 	workq_unlock(wq);
-
-	thread_mtx_unlock(thread);
 	return 0;
 }
 
@@ -2759,20 +2028,6 @@
 }
 
 static int
-workq_allow_sigmask(proc_t p, sigset_t mask)
-{
-	if (mask & workq_threadmask) {
-		return EINVAL;
-	}
-
-	proc_lock(p);
-	p->p_workq_allow_sigmask |= mask;
-	proc_unlock(p);
-
-	return 0;
-}
-
-static int
 bsdthread_get_max_parallelism(thread_qos_t qos, unsigned long flags,
     int *retval)
 {
@@ -2780,19 +2035,10 @@
 	    _PTHREAD_QOS_PARALLELISM_COUNT_LOGICAL, "logical");
 	static_assert(QOS_PARALLELISM_REALTIME ==
 	    _PTHREAD_QOS_PARALLELISM_REALTIME, "realtime");
-	static_assert(QOS_PARALLELISM_CLUSTER_SHARED_RESOURCE ==
-	    _PTHREAD_QOS_PARALLELISM_CLUSTER_SHARED_RSRC, "cluster shared resource");
-
-	if (flags & ~(QOS_PARALLELISM_REALTIME | QOS_PARALLELISM_COUNT_LOGICAL | QOS_PARALLELISM_CLUSTER_SHARED_RESOURCE)) {
+
+	if (flags & ~(QOS_PARALLELISM_REALTIME | QOS_PARALLELISM_COUNT_LOGICAL)) {
 		return EINVAL;
 	}
-
-#if !HAS_ARM_FEAT_SME
-	/* No units are present */
-	if (flags & QOS_PARALLELISM_CLUSTER_SHARED_RESOURCE) {
-		return ENOTSUP;
-	}
-#endif /* !HAS_ARM_FEAT_SME */
 
 	if (flags & QOS_PARALLELISM_REALTIME) {
 		if (qos) {
@@ -2804,30 +2050,6 @@
 
 	*retval = qos_max_parallelism(qos, flags);
 	return 0;
-}
-
-static int
-bsdthread_dispatch_apply_attr(__unused struct proc *p, thread_t thread,
-    unsigned long flags, uint64_t value1, __unused uint64_t value2)
-{
-	uint32_t apply_worker_index;
-	kern_return_t kr;
-
-	switch (flags) {
-	case _PTHREAD_DISPATCH_APPLY_ATTR_CLUSTER_SHARED_RSRC_SET:
-		apply_worker_index = (uint32_t)value1;
-		kr = thread_shared_rsrc_policy_set(thread, apply_worker_index, CLUSTER_SHARED_RSRC_TYPE_RR, SHARED_RSRC_POLICY_AGENT_DISPATCH);
-		/*
-		 * KERN_INVALID_POLICY indicates that the thread was trying to bind to a
-		 * cluster which it was not eligible to execute on.
-		 */
-		return (kr == KERN_SUCCESS) ? 0 : ((kr == KERN_INVALID_POLICY) ? ENOTSUP : EINVAL);
-	case _PTHREAD_DISPATCH_APPLY_ATTR_CLUSTER_SHARED_RSRC_CLEAR:
-		kr = thread_shared_rsrc_policy_clear(thread, CLUSTER_SHARED_RSRC_TYPE_RR, SHARED_RSRC_POLICY_AGENT_DISPATCH);
-		return (kr == KERN_SUCCESS) ? 0 : EINVAL;
-	default:
-		return EINVAL;
-	}
 }
 
 #define ENSURE_UNUSED(arg) \
@@ -2864,12 +2086,7 @@
 		ENSURE_UNUSED(uap->arg2);
 		ENSURE_UNUSED(uap->arg3);
 		return workq_thread_allow_kill(p, current_thread(), (bool)uap->arg1);
-	case BSDTHREAD_CTL_DISPATCH_APPLY_ATTR:
-		return bsdthread_dispatch_apply_attr(p, current_thread(),
-		           (unsigned long)uap->arg1, (uint64_t)uap->arg2,
-		           (uint64_t)uap->arg3);
-	case BSDTHREAD_CTL_WORKQ_ALLOW_SIGMASK:
-		return workq_allow_sigmask(p, (int)uap->arg1);
+
 	case BSDTHREAD_CTL_SET_QOS:
 	case BSDTHREAD_CTL_QOS_DISPATCH_ASYNCHRONOUS_OVERRIDE_ADD:
 	case BSDTHREAD_CTL_QOS_DISPATCH_ASYNCHRONOUS_OVERRIDE_RESET:
@@ -2911,58 +2128,38 @@
  * Entry point for libdispatch to ask for threads
  */
 static int
-workq_reqthreads(struct proc *p, uint32_t reqcount, pthread_priority_t pp, bool cooperative)
+workq_reqthreads(struct proc *p, uint32_t reqcount, pthread_priority_t pp)
 {
 	thread_qos_t qos = _pthread_priority_thread_qos(pp);
 	struct workqueue *wq = proc_get_wqptr(p);
 	uint32_t unpaced, upcall_flags = WQ_FLAG_THREAD_NEWSPI;
-	int ret = 0;
 
 	if (wq == NULL || reqcount <= 0 || reqcount > UINT16_MAX ||
 	    qos == THREAD_QOS_UNSPECIFIED) {
-		ret = EINVAL;
-		goto exit;
+		return EINVAL;
 	}
 
 	WQ_TRACE_WQ(TRACE_wq_wqops_reqthreads | DBG_FUNC_NONE,
-	    wq, reqcount, pp, cooperative);
+	    wq, reqcount, pp, 0, 0);
 
 	workq_threadreq_t req = zalloc(workq_zone_threadreq);
 	priority_queue_entry_init(&req->tr_entry);
 	req->tr_state = WORKQ_TR_STATE_NEW;
+	req->tr_flags = 0;
 	req->tr_qos   = qos;
-	workq_tr_flags_t tr_flags = 0;
 
 	if (pp & _PTHREAD_PRIORITY_OVERCOMMIT_FLAG) {
-		tr_flags |= WORKQ_TR_FLAG_OVERCOMMIT;
+		req->tr_flags |= WORKQ_TR_FLAG_OVERCOMMIT;
 		upcall_flags |= WQ_FLAG_THREAD_OVERCOMMIT;
 	}
 
-	if (cooperative) {
-		tr_flags |= WORKQ_TR_FLAG_COOPERATIVE;
-		upcall_flags |= WQ_FLAG_THREAD_COOPERATIVE;
-
-		if (reqcount > 1) {
-			ret = ENOTSUP;
-			goto free_and_exit;
-		}
-	}
-
-	/* A thread request cannot be both overcommit and cooperative */
-	if (workq_tr_is_cooperative(tr_flags) &&
-	    workq_tr_is_overcommit(tr_flags)) {
-		ret = EINVAL;
-		goto free_and_exit;
-	}
-	req->tr_flags = tr_flags;
-
 	WQ_TRACE_WQ(TRACE_wq_thread_request_initiate | DBG_FUNC_NONE,
-	    wq, workq_trace_req_id(req), req->tr_qos, reqcount);
+	    wq, workq_trace_req_id(req), req->tr_qos, reqcount, 0);
 
 	workq_lock_spin(wq);
 	do {
 		if (_wq_exiting(wq)) {
-			goto unlock_and_exit;
+			goto exiting;
 		}
 
 		/*
@@ -2975,19 +2172,13 @@
 		 * If there aren't enough threads, add one, but re-evaluate everything
 		 * as conditions may now have changed.
 		 */
-		unpaced = reqcount - 1;
-
-		if (reqcount > 1) {
-			/* We don't handle asking for parallelism on the cooperative
-			 * workqueue just yet */
-			assert(!workq_threadreq_is_cooperative(req));
-
-			if (workq_threadreq_is_nonovercommit(req)) {
-				unpaced = workq_constrained_allowance(wq, qos, NULL, false, true);
-				if (unpaced >= reqcount - 1) {
-					unpaced = reqcount - 1;
-				}
+		if (reqcount > 1 && (req->tr_flags & WORKQ_TR_FLAG_OVERCOMMIT) == 0) {
+			unpaced = workq_constrained_allowance(wq, qos, NULL, false);
+			if (unpaced >= reqcount - 1) {
+				unpaced = reqcount - 1;
 			}
+		} else {
+			unpaced = reqcount - 1;
 		}
 
 		/*
@@ -3004,7 +2195,7 @@
 			bool needs_wakeup;
 			uint8_t uu_flags = UT_WORKQ_EARLY_BOUND;
 
-			if (workq_tr_is_overcommit(req->tr_flags)) {
+			if (req->tr_flags & WORKQ_TR_FLAG_OVERCOMMIT) {
 				uu_flags |= UT_WORKQ_OVERCOMMIT;
 			}
 
@@ -3024,14 +2215,13 @@
 			reqcount--;
 		}
 	} while (unpaced && wq->wq_nthreads < wq_max_threads &&
-	    (workq_add_new_idle_thread(p, wq, workq_unpark_continue,
-	    false, NULL) == KERN_SUCCESS));
+	    workq_add_new_idle_thread(p, wq));
 
 	if (_wq_exiting(wq)) {
-		goto unlock_and_exit;
-	}
-
-	req->tr_count = (uint16_t)reqcount;
+		goto exiting;
+	}
+
+	req->tr_count = reqcount;
 	if (workq_threadreq_enqueue(wq, req)) {
 		/* This can drop the workqueue lock, and take it again */
 		workq_schedule_creator(p, wq, WORKQ_THREADREQ_CAN_CREATE_THREADS);
@@ -3039,12 +2229,10 @@
 	workq_unlock(wq);
 	return 0;
 
-unlock_and_exit:
+exiting:
 	workq_unlock(wq);
-free_and_exit:
 	zfree(workq_zone_threadreq, req);
-exit:
-	return ret;
+	return ECANCELED;
 }
 
 bool
@@ -3056,18 +2244,7 @@
 	struct uthread *uth = NULL;
 
 	assert(req->tr_flags & (WORKQ_TR_FLAG_WORKLOOP | WORKQ_TR_FLAG_KEVENT));
-	/*
-	 * Thread bound kqworkloops overlay the priority queue entry with other
-	 * data (the thread_t and work interval), so should never have their
-	 * threadreq passed here.
-	 */
-	assert(!(req->tr_flags & WORKQ_TR_FLAG_PERMANENT_BIND));
-
-	/*
-	 * For any new initialization changes done to workqueue thread request below,
-	 * please also consider if they are relevant to permanently bound thread
-	 * request. See workq_kern_threadreq_permanent_bind.
-	 */
+
 	if (req->tr_flags & WORKQ_TR_FLAG_WL_OUTSIDE_QOS) {
 		workq_threadreq_param_t trp = kqueue_threadreq_workloop_param(req);
 		qos = thread_workq_qos_for_pri(trp.trp_pri);
@@ -3083,7 +2260,7 @@
 	req->tr_qos   = qos;
 
 	WQ_TRACE_WQ(TRACE_wq_thread_request_initiate | DBG_FUNC_NONE, wq,
-	    workq_trace_req_id(req), qos, 1);
+	    workq_trace_req_id(req), qos, 1, 0);
 
 	if (flags & WORKQ_THREADREQ_ATTEMPT_REBIND) {
 		/*
@@ -3103,11 +2280,7 @@
 	}
 
 	if (uth && workq_threadreq_admissible(wq, uth, req)) {
-		/* This is the case of the rebind - we were about to park and unbind
-		 * when more events came so keep the binding.
-		 */
 		assert(uth != wq->wq_creator);
-
 		if (uth->uu_workq_pri.qos_bucket != req->tr_qos) {
 			_wq_thactive_move(wq, uth->uu_workq_pri.qos_bucket, req->tr_qos);
 			workq_thread_reset_pri(wq, uth, req, /*unpark*/ false);
@@ -3117,10 +2290,9 @@
 		 * due to an unbind, with the kq req held.
 		 */
 		WQ_TRACE_WQ(TRACE_wq_thread_logical_run | DBG_FUNC_START, wq,
-		    workq_trace_req_id(req), req->tr_flags, 0);
+		    workq_trace_req_id(req), 0, 0, 0);
 		wq->wq_fulfilled++;
-
-		kqueue_threadreq_bind(p, req, get_machthread(uth), 0);
+		kqueue_threadreq_bind(p, req, uth->uu_thread, 0);
 	} else {
 		if (workloop_ts) {
 			workq_perform_turnstile_operation_locked(wq, ^{
@@ -3130,14 +2302,7 @@
 				TURNSTILE_INTERLOCK_HELD);
 			});
 		}
-
-		bool reevaluate_creator_thread_group = false;
-#if CONFIG_PREADOPT_TG
-		reevaluate_creator_thread_group = (flags & WORKQ_THREADREQ_REEVALUATE_PREADOPT_TG);
-#endif
-		/* We enqueued the highest priority item or we may need to reevaluate if
-		 * the creator needs a thread group pre-adoption */
-		if (workq_threadreq_enqueue(wq, req) || reevaluate_creator_thread_group) {
+		if (workq_threadreq_enqueue(wq, req)) {
 			workq_schedule_creator(p, wq, flags);
 		}
 	}
@@ -3171,12 +2336,7 @@
 	}
 
 	if (flags & WORKQ_THREADREQ_MAKE_OVERCOMMIT) {
-		/* TODO (rokhinip): We come into this code path for kqwl thread
-		 * requests. kqwl requests cannot be cooperative.
-		 */
-		assert(!workq_threadreq_is_cooperative(req));
-
-		make_overcommit = workq_threadreq_is_nonovercommit(req);
+		make_overcommit = (req->tr_flags & WORKQ_TR_FLAG_OVERCOMMIT) == 0;
 	}
 
 	if (_wq_exiting(wq) || (req->tr_qos == qos && !make_overcommit)) {
@@ -3190,9 +2350,9 @@
 	}
 
 	WQ_TRACE_WQ(TRACE_wq_thread_request_modify | DBG_FUNC_NONE, wq,
-	    workq_trace_req_id(req), qos, 0);
-
-	struct priority_queue_sched_max *pq = workq_priority_queue_for_req(wq, req);
+	    workq_trace_req_id(req), qos, 0, 0);
+
+	struct priority_queue *pq = workq_priority_queue_for_req(wq, req);
 	workq_threadreq_t req_max;
 
 	/*
@@ -3201,8 +2361,9 @@
 	 * If we dequeue the root item of the constrained priority queue,
 	 * maintain the best constrained request qos invariant.
 	 */
-	if (priority_queue_remove(pq, &req->tr_entry)) {
-		if (workq_threadreq_is_nonovercommit(req)) {
+	if (priority_queue_remove(pq, &req->tr_entry,
+	    PRIORITY_QUEUE_SCHED_PRI_MAX_HEAP_COMPARE)) {
+		if ((req->tr_flags & WORKQ_TR_FLAG_OVERCOMMIT) == 0) {
 			_wq_thactive_refresh_best_constrained_req_qos(wq);
 		}
 	}
@@ -3221,9 +2382,8 @@
 
 	req_max = priority_queue_max(pq, struct workq_threadreq_s, tr_entry);
 	if (req_max && req_max->tr_qos >= qos) {
-		priority_queue_entry_set_sched_pri(pq, &req->tr_entry,
-		    workq_priority_for_req(req), false);
-		priority_queue_insert(pq, &req->tr_entry);
+		priority_queue_insert(pq, &req->tr_entry, workq_priority_for_req(req),
+		    PRIORITY_QUEUE_SCHED_PRI_MAX_HEAP_COMPARE);
 		workq_unlock(wq);
 		return;
 	}
@@ -3238,47 +2398,10 @@
 	 */
 	wq->wq_reqcount--;
 	req->tr_state = WORKQ_TR_STATE_NEW;
-
-	/* We enqueued the highest priority item or we may need to reevaluate if
-	 * the creator needs a thread group pre-adoption if the request got a new TG */
-	bool reevaluate_creator_tg = false;
-
-#if CONFIG_PREADOPT_TG
-	reevaluate_creator_tg = (flags & WORKQ_THREADREQ_REEVALUATE_PREADOPT_TG);
-#endif
-
-	if (workq_threadreq_enqueue(wq, req) || reevaluate_creator_tg) {
+	if (workq_threadreq_enqueue(wq, req)) {
 		workq_schedule_creator(p, wq, flags);
 	}
 	workq_unlock(wq);
-}
-
-void
-workq_kern_bound_thread_reset_pri(workq_threadreq_t req, struct uthread *uth)
-{
-	assert(workq_thread_is_permanently_bound(uth));
-
-	if (req && (req->tr_flags & WORKQ_TR_FLAG_WL_OUTSIDE_QOS)) {
-		/*
-		 * For requests outside-of-QoS, we set the scheduling policy and
-		 * absolute priority for the bound thread right at the initialization
-		 * time. See workq_kern_threadreq_permanent_bind.
-		 */
-		return;
-	}
-
-	struct workqueue *wq = proc_get_wqptr_fast(current_proc());
-	if (req) {
-		assert(req->tr_qos != WORKQ_THREAD_QOS_MANAGER);
-		workq_thread_reset_pri(wq, uth, req, /*unpark*/ true);
-	} else {
-		thread_qos_t qos = workq_pri_override(uth->uu_workq_pri);
-		if (qos > WORKQ_THREAD_QOS_CLEANUP) {
-			workq_thread_reset_pri(wq, uth, NULL, /*unpark*/ true);
-		} else {
-			uth->uu_save.uus_workq_park_data.qos = qos;
-		}
-	}
 }
 
 void
@@ -3307,7 +2430,7 @@
 
 	if (req->tr_state == WORKQ_TR_STATE_BINDING) {
 		kqueue_threadreq_bind(p, req, req->tr_thread,
-		    KQUEUE_THREADREQ_BIND_NO_INHERITOR_UPDATE);
+		    KQUEUE_THREADERQ_BIND_NO_INHERITOR_UPDATE);
 		return;
 	}
 
@@ -3332,223 +2455,6 @@
 	});
 }
 
-/*
- * An entry point for kevent to request a newly created workqueue thread
- * and bind it permanently to the given workqueue thread request.
- *
- * It currently only supports fixed scheduler priority thread requests.
- *
- * The newly created thread counts towards wq_nthreads. This function returns
- * an error if we are above that limit. There is no concept of delayed thread
- * creation for such specially configured kqworkloops.
- *
- * If successful, the newly created thread will be parked in
- * workq_bound_thread_initialize_and_unpark_continue waiting for
- * new incoming events.
- */
-kern_return_t
-workq_kern_threadreq_permanent_bind(struct proc *p, struct workq_threadreq_s *kqr)
-{
-	kern_return_t ret = 0;
-	thread_t new_thread = NULL;
-	struct workqueue *wq = proc_get_wqptr_fast(p);
-
-	workq_lock_spin(wq);
-
-	if (wq->wq_nthreads >= wq_max_threads) {
-		ret = EDOM;
-	} else {
-		if (kqr->tr_flags & WORKQ_TR_FLAG_WL_OUTSIDE_QOS) {
-			workq_threadreq_param_t trp = kqueue_threadreq_workloop_param(kqr);
-			/*
-			 * For requests outside-of-QoS, we fully initialize the thread
-			 * request here followed by preadopting the scheduling properties
-			 * on the newly created bound thread.
-			 */
-			thread_qos_t qos = thread_workq_qos_for_pri(trp.trp_pri);
-			if (qos == THREAD_QOS_UNSPECIFIED) {
-				qos = WORKQ_THREAD_QOS_ABOVEUI;
-			}
-			kqr->tr_qos = qos;
-		}
-		kqr->tr_count = 1;
-
-		/* workq_lock dropped and retaken around thread creation below. */
-		ret = workq_add_new_idle_thread(p, wq,
-		    workq_bound_thread_initialize_and_unpark_continue,
-		    true, &new_thread);
-		if (ret == KERN_SUCCESS) {
-			struct uthread *uth = get_bsdthread_info(new_thread);
-			if (kqr->tr_flags & WORKQ_TR_FLAG_WL_OUTSIDE_QOS) {
-				workq_thread_reset_pri(wq, uth, kqr, /*unpark*/ true);
-			}
-			/*
-			 * The newly created thread goes through a full bind to the kqwl
-			 * right upon creation.
-			 * It then falls back to soft bind/unbind upon wakeup/park.
-			 */
-			kqueue_threadreq_bind_prepost(p, kqr, uth);
-			uth->uu_workq_flags |= UT_WORKQ_PERMANENT_BIND;
-		}
-	}
-
-	workq_unlock(wq);
-
-	if (ret == KERN_SUCCESS) {
-		kqueue_threadreq_bind_commit(p, new_thread);
-	}
-	return ret;
-}
-
-/*
- * Called with kqlock held. It does not need to take the process wide
- * global workq lock -> making it faster.
- */
-void
-workq_kern_bound_thread_wakeup(struct workq_threadreq_s *kqr)
-{
-	struct uthread *uth = get_bsdthread_info(kqr->tr_thread);
-	workq_threadreq_param_t trp = kqueue_threadreq_workloop_param(kqr);
-
-	/*
-	 * See "Locking model for accessing uu_workq_flags" for more information
-	 * on how access to uu_workq_flags for the bound thread is synchronized.
-	 */
-	assert((uth->uu_workq_flags & (UT_WORKQ_RUNNING | UT_WORKQ_DYING)) == 0);
-
-	if (trp.trp_flags & TRP_RELEASED) {
-		uth->uu_workq_flags |= UT_WORKQ_DYING;
-	} else {
-		uth->uu_workq_flags |= UT_WORKQ_RUNNING;
-	}
-
-	workq_thread_wakeup(uth);
-}
-
-/*
- * Called with kqlock held. Dropped before parking.
- * It does not need to take process wide global workqueue
- * lock -> making it faster.
- */
-__attribute__((noreturn, noinline))
-void
-workq_kern_bound_thread_park(struct workq_threadreq_s *kqr)
-{
-	struct uthread *uth = get_bsdthread_info(kqr->tr_thread);
-	assert(uth == current_uthread());
-
-	/*
-	 * See "Locking model for accessing uu_workq_flags" for more information
-	 * on how access to uu_workq_flags for the bound thread is synchronized.
-	 */
-	uth->uu_workq_flags &= ~(UT_WORKQ_RUNNING);
-
-	thread_disarm_workqueue_quantum(get_machthread(uth));
-
-	/*
-	 * TODO (pavhad) We could do the reusable userspace stack performance
-	 * optimization here.
-	 */
-
-	kqworkloop_bound_thread_park_prepost(kqr);
-	/* KQ_SLEEP bit is set and kqlock is dropped. */
-
-	__assert_only kern_return_t kr;
-	kr = thread_set_voucher_name(MACH_PORT_NULL);
-	assert(kr == KERN_SUCCESS);
-
-	/*
-	 * Bound threads park (and unpark) with the scheduler callback cleared and
-	 * not counting towards thactive. If we unpark to do work (as opposed to
-	 * waking up to thread exit), the scheduler callback is added via
-	 * workq_setup_and_run, and thactive is incremented in
-	 * workq_bound_thread_setup_and_run.
-	 */
-	thread_sched_call(get_machthread(uth), NULL);
-	proc_t p = current_proc();
-	struct workqueue *wq = proc_get_wqptr_fast(p);
-	_wq_thactive_dec(wq, uth->uu_workq_pri.qos_bucket);
-
-	kqworkloop_bound_thread_park_commit(kqr,
-	    workq_parked_wait_event(uth), workq_bound_thread_unpark_continue);
-
-	__builtin_unreachable();
-}
-
-/*
- * To terminate the permenantly bound workqueue thread. It unbinds itself
- * with the kqwl during uthread_cleanup -> kqueue_threadreq_unbind.
- * It is also when it will release its reference on the kqwl.
- */
-__attribute__((noreturn, noinline))
-void
-workq_kern_bound_thread_terminate(struct workq_threadreq_s *kqr)
-{
-	proc_t p = current_proc();
-	struct uthread *uth = get_bsdthread_info(kqr->tr_thread);
-	uint16_t uu_workq_flags_orig;
-
-	assert(uth == current_uthread());
-
-	/*
-	 * See "Locking model for accessing uu_workq_flags" for more information
-	 * on how access to uu_workq_flags for the bound thread is synchronized.
-	 */
-	kqworkloop_bound_thread_terminate(kqr, &uu_workq_flags_orig);
-
-	if (uu_workq_flags_orig & UT_WORKQ_WORK_INTERVAL_JOINED) {
-		__assert_only kern_return_t kr;
-		kr = kern_work_interval_join(get_machthread(uth), MACH_PORT_NULL);
-		/* The bound thread un-joins the work interval and drops its +1 ref. */
-		assert(kr == KERN_SUCCESS);
-	}
-
-	/*
-	 * Drop the voucher now that we are on our way to termination.
-	 */
-	__assert_only kern_return_t kr;
-	kr = thread_set_voucher_name(MACH_PORT_NULL);
-	assert(kr == KERN_SUCCESS);
-
-	uint32_t upcall_flags = WQ_FLAG_THREAD_NEWSPI;
-	upcall_flags |= uth->uu_save.uus_workq_park_data.qos |
-	    WQ_FLAG_THREAD_PRIO_QOS;
-
-	thread_t th = get_machthread(uth);
-	vm_map_t vmap = get_task_map(proc_task(p));
-
-	uint32_t setup_flags = WQ_SETUP_EXIT_THREAD;
-
-	if ((uu_workq_flags_orig & UT_WORKQ_NEW) == 0) {
-		upcall_flags |= WQ_FLAG_THREAD_REUSE;
-	} else {
-		/*
-		 * The bound thread is exiting before ever having gone to userspace. We
-		 * need pthread to perform initial setup before calling _pthread_exit.
-		 * TODO(aaron): We should investigate an optimization both here and in
-		 * workq_unpark_for_death_and_unlock to never send these threads to
-		 * userspace, instead processing ASTs and calling destroying the stack.
-		 */
-		setup_flags |= WQ_SETUP_FIRST_USE;
-
-		/*
-		 * Typically we'd set the workq_thport in workq_setup_and_run, but we
-		 * haven't been through that path yet.
-		 */
-		assert(uth->uu_workq_thport == MACH_PORT_NULL);
-		/* convert_thread_to_port_immovable() consumes a reference */
-		thread_reference(th);
-		/* Convert to immovable thread port, then pin the entry */
-		uth->uu_workq_thport = ipc_port_copyout_send_pinned(
-			convert_thread_to_port_immovable(th),
-			get_task_ipcspace(proc_task(p)));
-	}
-
-	pthread_functions->workq_setup_thread(p, th, vmap, uth->uu_workq_stackaddr,
-	    uth->uu_workq_thport, 0, setup_flags, upcall_flags);
-	__builtin_unreachable();
-}
-
 void
 workq_kern_threadreq_redrive(struct proc *p, workq_kern_threadreq_flags_t flags)
 {
@@ -3557,74 +2463,6 @@
 	workq_lock_spin(wq);
 	workq_schedule_creator(p, wq, flags);
 	workq_unlock(wq);
-}
-
-/*
- * Always called at AST by the thread on itself
- *
- * Upon quantum expiry, the workqueue subsystem evaluates its state and decides
- * on what the thread should do next. The TSD value is always set by the thread
- * on itself in the kernel and cleared either by userspace when it acks the TSD
- * value and takes action, or by the thread in the kernel when the quantum
- * expires again.
- */
-void
-workq_kern_quantum_expiry_reevaluate(proc_t proc, thread_t thread)
-{
-	struct uthread *uth = get_bsdthread_info(thread);
-
-	if (uth->uu_workq_flags & UT_WORKQ_DYING) {
-		return;
-	}
-
-	if (!thread_supports_cooperative_workqueue(thread)) {
-		panic("Quantum expired for thread that doesn't support cooperative workqueue");
-	}
-
-	thread_qos_t qos = uth->uu_workq_pri.qos_bucket;
-	if (qos == THREAD_QOS_UNSPECIFIED) {
-		panic("Thread should not have workq bucket of QoS UN");
-	}
-
-	assert(thread_has_expired_workqueue_quantum(thread, false));
-
-	struct workqueue *wq = proc_get_wqptr(proc);
-	assert(wq != NULL);
-
-	/*
-	 * For starters, we're just going to evaluate and see if we need to narrow
-	 * the pool and tell this thread to park if needed. In the future, we'll
-	 * evaluate and convey other workqueue state information like needing to
-	 * pump kevents, etc.
-	 */
-	uint64_t flags = 0;
-
-	workq_lock_spin(wq);
-
-	if (workq_thread_is_cooperative(uth)) {
-		if (!workq_cooperative_allowance(wq, qos, uth, false)) {
-			flags |= PTHREAD_WQ_QUANTUM_EXPIRY_NARROW;
-		} else {
-			/* In the future, when we have kevent hookups for the cooperative
-			 * pool, we need fancier logic for what userspace should do. But
-			 * right now, only userspace thread requests exist - so we'll just
-			 * tell userspace to shuffle work items */
-			flags |= PTHREAD_WQ_QUANTUM_EXPIRY_SHUFFLE;
-		}
-	} else if (workq_thread_is_nonovercommit(uth)) {
-		if (!workq_constrained_allowance(wq, qos, uth, false, false)) {
-			flags |= PTHREAD_WQ_QUANTUM_EXPIRY_NARROW;
-		}
-	}
-	workq_unlock(wq);
-
-	WQ_TRACE(TRACE_wq_quantum_expiry_reevaluate, flags, 0, 0, 0);
-
-	kevent_set_workq_quantum_expiry_user_tsd(proc, thread, flags);
-
-	/* We have conveyed to userspace about what it needs to do upon quantum
-	 * expiry, now rearm the workqueue quantum again */
-	thread_arm_workqueue_quantum(get_machthread(uth));
 }
 
 void
@@ -3657,14 +2495,10 @@
 		return EINVAL;
 	}
 
-	/*
-	 * Reset signal mask on the workqueue thread to default state,
-	 * but do not touch any signals that are marked for preservation.
-	 */
-	sigset_t resettable = uth->uu_sigmask & ~p->p_workq_allow_sigmask;
-	if (resettable != (sigset_t)~workq_threadmask) {
+	/* reset signal mask on the workqueue thread to default state */
+	if (uth->uu_sigmask != (sigset_t)(~workq_threadmask)) {
 		proc_lock(p);
-		uth->uu_sigmask |= ~workq_threadmask & ~p->p_workq_allow_sigmask;
+		uth->uu_sigmask = ~workq_threadmask;
 		proc_unlock(p);
 	}
 
@@ -3676,12 +2510,8 @@
 		trp = kqueue_threadreq_workloop_param(kqr);
 	}
 
-	if (kqr && kqr->tr_flags & WORKQ_TR_FLAG_PERMANENT_BIND) {
-		goto handle_stack_events;
-	}
-
 	/*
-	 * Freeze the base pri while we decide the fate of this thread.
+	 * Freeze thee base pri while we decide the fate of this thread.
 	 *
 	 * Either:
 	 * - we return to user and kevent_cleanup will have unfrozen the base pri,
@@ -3689,8 +2519,6 @@
 	 */
 	thread_freeze_base_pri(th);
 
-handle_stack_events:
-
 	if (kqr) {
 		uint32_t upcall_flags = WQ_FLAG_THREAD_NEWSPI | WQ_FLAG_THREAD_REUSE;
 		if (kqr->tr_flags & WORKQ_TR_FLAG_WORKLOOP) {
@@ -3701,7 +2529,7 @@
 		if (uth->uu_workq_pri.qos_bucket == WORKQ_THREAD_QOS_MANAGER) {
 			upcall_flags |= WQ_FLAG_THREAD_EVENT_MANAGER;
 		} else {
-			if (workq_thread_is_overcommit(uth)) {
+			if (uth->uu_workq_flags & UT_WORKQ_OVERCOMMIT) {
 				upcall_flags |= WQ_FLAG_THREAD_OVERCOMMIT;
 			}
 			if (uth->uu_workq_flags & UT_WORKQ_OUTSIDE_QOS) {
@@ -3711,8 +2539,9 @@
 				    WQ_FLAG_THREAD_PRIO_QOS;
 			}
 		}
+
 		error = pthread_functions->workq_handle_stack_events(p, th,
-		    get_task_map(proc_task(p)), uth->uu_workq_stackaddr,
+		    get_task_map(p->task), uth->uu_workq_stackaddr,
 		    uth->uu_workq_thport, eventlist, nevents, upcall_flags);
 		if (error) {
 			assert(uth->uu_kqr_bound == kqr);
@@ -3727,7 +2556,7 @@
 		assert(uth->uu_kqr_bound == NULL);
 	}
 
-	WQ_TRACE_WQ(TRACE_wq_runthread | DBG_FUNC_END, wq, uap->options, 0, 0);
+	WQ_TRACE_WQ(TRACE_wq_runthread | DBG_FUNC_END, wq, uap->options, 0, 0, 0);
 
 	thread_sched_call(th, NULL);
 	thread_will_park_or_terminate(th);
@@ -3736,7 +2565,7 @@
 #endif
 
 	workq_lock_spin(wq);
-	WQ_TRACE_WQ(TRACE_wq_thread_logical_run | DBG_FUNC_END, wq, 0, 0, 0);
+	WQ_TRACE_WQ(TRACE_wq_thread_logical_run | DBG_FUNC_END, wq, 0, 0, 0, 0);
 	uth->uu_save.uus_workq_park_data.workloop_params = trp.trp_value;
 	workq_select_threadreq_or_park_and_unlock(p, wq, uth,
 	    WQ_SETUP_CLEAR_VOUCHER);
@@ -3778,16 +2607,7 @@
 		 * arg2 = number of threads to start
 		 * arg3 = priority
 		 */
-		error = workq_reqthreads(p, arg2, arg3, false);
-		break;
-	}
-	/* For requesting threads for the cooperative pool */
-	case WQOPS_QUEUE_REQTHREADS2: {
-		/*
-		 * arg2 = number of threads to start
-		 * arg3 = priority
-		 */
-		error = workq_reqthreads(p, arg2, arg3, true);
+		error = workq_reqthreads(p, arg2, arg3);
 		break;
 	}
 	case WQOPS_SET_EVENT_MANAGER_PRIORITY: {
@@ -3808,7 +2628,7 @@
 		/*
 		 * Normalize the incoming priority so that it is ordered numerically.
 		 */
-		if (_pthread_priority_has_sched_pri(pri)) {
+		if (pri & _PTHREAD_PRIORITY_SCHED_PRI_FLAG) {
 			pri &= (_PTHREAD_PRIORITY_SCHED_PRI_MASK |
 			    _PTHREAD_PRIORITY_SCHED_PRI_FLAG);
 		} else {
@@ -3859,7 +2679,7 @@
 			break;
 		}
 		workq_lock_spin(wq);
-		bool should_narrow = !workq_constrained_allowance(wq, qos, uth, false, false);
+		bool should_narrow = !workq_constrained_allowance(wq, qos, uth, false);
 		workq_unlock(wq);
 
 		*retval = should_narrow;
@@ -3918,28 +2738,6 @@
 
 	workq_thread_reset_cpupercent(NULL, uth);
 
-#if CONFIG_PREADOPT_TG
-	/* Clear the preadoption thread group on the thread.
-	 *
-	 * Case 1:
-	 *		Creator thread which never picked up a thread request. We set a
-	 *		preadoption thread group on creator threads but if it never picked
-	 *		up a thread request and didn't go to userspace, then the thread will
-	 *		park with a preadoption thread group but no explicitly adopted
-	 *		voucher or work interval.
-	 *
-	 *		We drop the preadoption thread group here before proceeding to park.
-	 *		Note - we may get preempted when we drop the workq lock below.
-	 *
-	 * Case 2:
-	 *		Thread picked up a thread request and bound to it and returned back
-	 *		from userspace and is parking. At this point, preadoption thread
-	 *		group should be NULL since the thread has unbound from the thread
-	 *		request. So this operation should be a no-op.
-	 */
-	thread_set_preadopt_thread_group(get_machthread(uth), NULL);
-#endif
-
 	if ((uth->uu_workq_flags & UT_WORKQ_IDLE_CLEANUP) &&
 	    !(uth->uu_workq_flags & UT_WORKQ_DYING)) {
 		workq_unlock(wq);
@@ -3949,9 +2747,8 @@
 		 * if it wants us to free the stack before parking.
 		 */
 		if (!uth->uu_save.uus_workq_park_data.has_stack) {
-			pthread_functions->workq_markfree_threadstack(p,
-			    get_machthread(uth), get_task_map(proc_task(p)),
-			    uth->uu_workq_stackaddr);
+			pthread_functions->workq_markfree_threadstack(p, uth->uu_thread,
+			    get_task_map(p->task), uth->uu_workq_stackaddr);
 		}
 
 		/*
@@ -3960,10 +2757,6 @@
 		 * the idle list.  Then, when we get our importance back we'll be able to
 		 * use this thread from e.g. the kevent call out to deliver a boosting
 		 * message.
-		 *
-		 * Note that setting the voucher to NULL will not clear the preadoption
-		 * thread since this thread could have become the creator again and
-		 * perhaps acquired a preadoption thread group.
 		 */
 		__assert_only kern_return_t kr;
 		kr = thread_set_voucher_name(MACH_PORT_NULL);
@@ -3973,8 +2766,6 @@
 		uth->uu_workq_flags &= ~UT_WORKQ_IDLE_CLEANUP;
 		setup_flags &= ~WQ_SETUP_CLEAR_VOUCHER;
 	}
-
-	WQ_TRACE_WQ(TRACE_wq_thread_logical_run | DBG_FUNC_END, wq, 0, 0, 0);
 
 	if (uth->uu_workq_flags & UT_WORKQ_RUNNING) {
 		/*
@@ -3983,6 +2774,7 @@
 		 * event their thread_wakeup() was ineffectual.  To correct for that,
 		 * we just run the continuation ourselves.
 		 */
+		WQ_TRACE_WQ(TRACE_wq_thread_logical_run | DBG_FUNC_END, wq, 0, 0, 0, 0);
 		workq_unpark_select_threadreq_or_park_and_unlock(p, wq, uth, setup_flags);
 		__builtin_unreachable();
 	}
@@ -3993,12 +2785,10 @@
 		__builtin_unreachable();
 	}
 
-	/* Disarm the workqueue quantum since the thread is now idle */
-	thread_disarm_workqueue_quantum(get_machthread(uth));
-
-	thread_set_pending_block_hint(get_machthread(uth), kThreadWaitParkedWorkQueue);
+	thread_set_pending_block_hint(uth->uu_thread, kThreadWaitParkedWorkQueue);
 	assert_wait(workq_parked_wait_event(uth), THREAD_INTERRUPTIBLE);
 	workq_unlock(wq);
+	WQ_TRACE_WQ(TRACE_wq_thread_logical_run | DBG_FUNC_END, wq, 0, 0, 0, 0);
 	thread_block(workq_unpark_continue);
 	__builtin_unreachable();
 }
@@ -4015,17 +2805,15 @@
 	       (uth && uth->uu_workq_pri.qos_bucket == WORKQ_THREAD_QOS_MANAGER);
 }
 
-/* Called with workq lock held. */
 static uint32_t
 workq_constrained_allowance(struct workqueue *wq, thread_qos_t at_qos,
-    struct uthread *uth, bool may_start_timer, bool record_failed_allowance)
+    struct uthread *uth, bool may_start_timer)
 {
 	assert(at_qos != WORKQ_THREAD_QOS_MANAGER);
-	uint32_t allowance_passed = 0;
 	uint32_t count = 0;
 
 	uint32_t max_count = wq->wq_constrained_threads_scheduled;
-	if (uth && workq_thread_is_nonovercommit(uth)) {
+	if (uth && (uth->uu_workq_flags & UT_WORKQ_OVERCOMMIT) == 0) {
 		/*
 		 * don't count the current thread as scheduled
 		 */
@@ -4035,26 +2823,22 @@
 	if (max_count >= wq_max_constrained_threads) {
 		WQ_TRACE_WQ(TRACE_wq_constrained_admission | DBG_FUNC_NONE, wq, 1,
 		    wq->wq_constrained_threads_scheduled,
-		    wq_max_constrained_threads);
+		    wq_max_constrained_threads, 0);
 		/*
 		 * we need 1 or more constrained threads to return to the kernel before
 		 * we can dispatch additional work
 		 */
-		allowance_passed = 0;
-		goto out;
+		return 0;
 	}
 	max_count -= wq_max_constrained_threads;
 
 	/*
 	 * Compute a metric for many how many threads are active.  We find the
-	 * highest priority request outstanding and then add up the number of active
-	 * threads in that and all higher-priority buckets.  We'll also add any
-	 * "busy" threads which are not currently active but blocked recently enough
-	 * that we can't be sure that they won't be unblocked soon and start
-	 * being active again.
-	 *
-	 * We'll then compare this metric to our max concurrency to decide whether
-	 * to add a new thread.
+	 * highest priority request outstanding and then add up the number of
+	 * active threads in that and all higher-priority buckets.  We'll also add
+	 * any "busy" threads which are not active but blocked recently enough that
+	 * we can't be sure they've gone idle yet.  We'll then compare this metric
+	 * to our max concurrency to decide whether to add a new thread.
 	 */
 
 	uint32_t busycount, thactive_count;
@@ -4077,16 +2861,14 @@
 	if (count > thactive_count + busycount) {
 		count -= thactive_count + busycount;
 		WQ_TRACE_WQ(TRACE_wq_constrained_admission | DBG_FUNC_NONE, wq, 2,
-		    thactive_count, busycount);
-		allowance_passed = MIN(count, max_count);
-		goto out;
+		    thactive_count, busycount, 0);
+		return MIN(count, max_count);
 	} else {
 		WQ_TRACE_WQ(TRACE_wq_constrained_admission | DBG_FUNC_NONE, wq, 3,
-		    thactive_count, busycount);
-		allowance_passed = 0;
-	}
-
-	if (may_start_timer) {
+		    thactive_count, busycount, 0);
+	}
+
+	if (busycount && may_start_timer) {
 		/*
 		 * If this is called from the add timer, we won't have another timer
 		 * fire when the thread exits the "busy" state, so rearm the timer.
@@ -4094,11 +2876,7 @@
 		workq_schedule_delayed_thread_creation(wq, 0);
 	}
 
-out:
-	if (record_failed_allowance) {
-		wq->wq_exceeded_active_constrained_thread_limit = !allowance_passed;
-	}
-	return allowance_passed;
+	return 0;
 }
 
 static bool
@@ -4108,67 +2886,23 @@
 	if (req->tr_qos == WORKQ_THREAD_QOS_MANAGER) {
 		return workq_may_start_event_mgr_thread(wq, uth);
 	}
-	if (workq_threadreq_is_cooperative(req)) {
-		return workq_cooperative_allowance(wq, req->tr_qos, uth, true);
-	}
-	if (workq_threadreq_is_nonovercommit(req)) {
-		return workq_constrained_allowance(wq, req->tr_qos, uth, true, true);
-	}
-
+	if ((req->tr_flags & WORKQ_TR_FLAG_OVERCOMMIT) == 0) {
+		return workq_constrained_allowance(wq, req->tr_qos, uth, true);
+	}
 	return true;
-}
-
-/*
- * Called from the context of selecting thread requests for threads returning
- * from userspace or creator thread
- */
-static workq_threadreq_t
-workq_cooperative_queue_best_req(struct workqueue *wq, struct uthread *uth)
-{
-	workq_lock_held(wq);
-
-	/*
-	 * If the current thread is cooperative, we need to exclude it as part of
-	 * cooperative schedule count since this thread is looking for a new
-	 * request. Change in the schedule count for cooperative pool therefore
-	 * requires us to reeevaluate the next best request for it.
-	 */
-	if (uth && workq_thread_is_cooperative(uth)) {
-		_wq_cooperative_queue_scheduled_count_dec(wq, uth->uu_workq_pri.qos_req);
-
-		(void) _wq_cooperative_queue_refresh_best_req_qos(wq);
-
-		_wq_cooperative_queue_scheduled_count_inc(wq, uth->uu_workq_pri.qos_req);
-	} else {
-		/*
-		 * The old value that was already precomputed should be safe to use -
-		 * add an assert that asserts that the best req QoS doesn't change in
-		 * this case
-		 */
-		assert(_wq_cooperative_queue_refresh_best_req_qos(wq) == false);
-	}
-
-	thread_qos_t qos = wq->wq_cooperative_queue_best_req_qos;
-
-	/* There are no eligible requests in the cooperative pool */
-	if (qos == THREAD_QOS_UNSPECIFIED) {
-		return NULL;
-	}
-	assert(qos != WORKQ_THREAD_QOS_ABOVEUI);
-	assert(qos != WORKQ_THREAD_QOS_MANAGER);
-
-	uint8_t bucket = _wq_bucket(qos);
-	assert(!STAILQ_EMPTY(&wq->wq_cooperative_queue[bucket]));
-
-	return STAILQ_FIRST(&wq->wq_cooperative_queue[bucket]);
 }
 
 static workq_threadreq_t
 workq_threadreq_select_for_creator(struct workqueue *wq)
 {
-	workq_threadreq_t req_qos, req_pri, req_tmp, req_mgr;
+	workq_threadreq_t req_qos, req_pri, req_tmp;
 	thread_qos_t qos = THREAD_QOS_UNSPECIFIED;
 	uint8_t pri = 0;
+
+	req_tmp = wq->wq_event_manager_threadreq;
+	if (req_tmp && workq_may_start_event_mgr_thread(wq, NULL)) {
+		return req_tmp;
+	}
 
 	/*
 	 * Compute the best priority request, and ignore the turnstile for now
@@ -4177,72 +2911,28 @@
 	req_pri = priority_queue_max(&wq->wq_special_queue,
 	    struct workq_threadreq_s, tr_entry);
 	if (req_pri) {
-		pri = (uint8_t)priority_queue_entry_sched_pri(&wq->wq_special_queue,
-		    &req_pri->tr_entry);
-	}
-
-	/*
-	 * Handle the manager thread request. The special queue might yield
-	 * a higher priority, but the manager always beats the QoS world.
-	 */
-
-	req_mgr = wq->wq_event_manager_threadreq;
-	if (req_mgr && workq_may_start_event_mgr_thread(wq, NULL)) {
-		uint32_t mgr_pri = wq->wq_event_manager_priority;
-
-		if (mgr_pri & _PTHREAD_PRIORITY_SCHED_PRI_FLAG) {
-			mgr_pri &= _PTHREAD_PRIORITY_SCHED_PRI_MASK;
-		} else {
-			mgr_pri = thread_workq_pri_for_qos(
-				_pthread_priority_thread_qos(mgr_pri));
-		}
-
-		return mgr_pri >= pri ? req_mgr : req_pri;
+		pri = priority_queue_entry_key(&wq->wq_special_queue, &req_pri->tr_entry);
 	}
 
 	/*
 	 * Compute the best QoS Request, and check whether it beats the "pri" one
-	 *
-	 * Start by comparing the overcommit and the cooperative pool
 	 */
+
 	req_qos = priority_queue_max(&wq->wq_overcommit_queue,
 	    struct workq_threadreq_s, tr_entry);
 	if (req_qos) {
 		qos = req_qos->tr_qos;
 	}
 
-	req_tmp = workq_cooperative_queue_best_req(wq, NULL);
-	if (req_tmp && qos <= req_tmp->tr_qos) {
-		/*
-		 * Cooperative TR is better between overcommit and cooperative.  Note
-		 * that if qos is same between overcommit and cooperative, we choose
-		 * cooperative.
-		 *
-		 * Pick cooperative pool if it passes the admissions check
-		 */
-		if (workq_cooperative_allowance(wq, req_tmp->tr_qos, NULL, true)) {
-			req_qos = req_tmp;
-			qos = req_qos->tr_qos;
-		}
-	}
-
-	/*
-	 * Compare the best QoS so far - either from overcommit or from cooperative
-	 * pool - and compare it with the constrained pool
-	 */
 	req_tmp = priority_queue_max(&wq->wq_constrained_queue,
 	    struct workq_threadreq_s, tr_entry);
 
 	if (req_tmp && qos < req_tmp->tr_qos) {
-		/*
-		 * Constrained pool is best in QoS between overcommit, cooperative
-		 * and constrained. Now check how it fairs against the priority case
-		 */
 		if (pri && pri >= thread_workq_pri_for_qos(req_tmp->tr_qos)) {
 			return req_pri;
 		}
 
-		if (workq_constrained_allowance(wq, req_tmp->tr_qos, NULL, true, true)) {
+		if (workq_constrained_allowance(wq, req_tmp->tr_qos, NULL, true)) {
 			/*
 			 * If the constrained thread request is the best one and passes
 			 * the admission check, pick it.
@@ -4251,9 +2941,6 @@
 		}
 	}
 
-	/*
-	 * Compare the best of the QoS world with the priority
-	 */
 	if (pri && (!qos || pri >= thread_workq_pri_for_qos(qos))) {
 		return req_pri;
 	}
@@ -4281,82 +2968,10 @@
 	return NULL;
 }
 
-/*
- * Returns true if this caused a change in the schedule counts of the
- * cooperative pool
- */
-static bool
-workq_adjust_cooperative_constrained_schedule_counts(struct workqueue *wq,
-    struct uthread *uth, thread_qos_t old_thread_qos, workq_tr_flags_t tr_flags)
-{
-	workq_lock_held(wq);
-
-	/*
-	 * Row: thread type
-	 * Column: Request type
-	 *
-	 *					overcommit		non-overcommit		cooperative
-	 * overcommit			X				case 1				case 2
-	 * cooperative		case 3				case 4				case 5
-	 * non-overcommit	case 6					X				case 7
-	 *
-	 * Move the thread to the right bucket depending on what state it currently
-	 * has and what state the thread req it picks, is going to have.
-	 *
-	 * Note that the creator thread is an overcommit thread.
-	 */
-	thread_qos_t new_thread_qos = uth->uu_workq_pri.qos_req;
-
-	/*
-	 * Anytime a cooperative bucket's schedule count changes, we need to
-	 * potentially refresh the next best QoS for that pool when we determine
-	 * the next request for the creator
-	 */
-	bool cooperative_pool_sched_count_changed = false;
-
-	if (workq_thread_is_overcommit(uth)) {
-		if (workq_tr_is_nonovercommit(tr_flags)) {
-			// Case 1: thread is overcommit, req is non-overcommit
-			wq->wq_constrained_threads_scheduled++;
-		} else if (workq_tr_is_cooperative(tr_flags)) {
-			// Case 2: thread is overcommit, req is cooperative
-			_wq_cooperative_queue_scheduled_count_inc(wq, new_thread_qos);
-			cooperative_pool_sched_count_changed = true;
-		}
-	} else if (workq_thread_is_cooperative(uth)) {
-		if (workq_tr_is_overcommit(tr_flags)) {
-			// Case 3: thread is cooperative, req is overcommit
-			_wq_cooperative_queue_scheduled_count_dec(wq, old_thread_qos);
-		} else if (workq_tr_is_nonovercommit(tr_flags)) {
-			// Case 4: thread is cooperative, req is non-overcommit
-			_wq_cooperative_queue_scheduled_count_dec(wq, old_thread_qos);
-			wq->wq_constrained_threads_scheduled++;
-		} else {
-			// Case 5: thread is cooperative, req is also cooperative
-			assert(workq_tr_is_cooperative(tr_flags));
-			_wq_cooperative_queue_scheduled_count_dec(wq, old_thread_qos);
-			_wq_cooperative_queue_scheduled_count_inc(wq, new_thread_qos);
-		}
-		cooperative_pool_sched_count_changed = true;
-	} else {
-		if (workq_tr_is_overcommit(tr_flags)) {
-			// Case 6: Thread is non-overcommit, req is overcommit
-			wq->wq_constrained_threads_scheduled--;
-		} else if (workq_tr_is_cooperative(tr_flags)) {
-			// Case 7: Thread is non-overcommit, req is cooperative
-			wq->wq_constrained_threads_scheduled--;
-			_wq_cooperative_queue_scheduled_count_inc(wq, new_thread_qos);
-			cooperative_pool_sched_count_changed = true;
-		}
-	}
-
-	return cooperative_pool_sched_count_changed;
-}
-
 static workq_threadreq_t
 workq_threadreq_select(struct workqueue *wq, struct uthread *uth)
 {
-	workq_threadreq_t req_qos, req_pri, req_tmp, req_mgr;
+	workq_threadreq_t req_qos, req_pri, req_tmp;
 	uintptr_t proprietor;
 	thread_qos_t qos = THREAD_QOS_UNSPECIFIED;
 	uint8_t pri = 0;
@@ -4365,11 +2980,16 @@
 		uth = NULL;
 	}
 
+	req_tmp = wq->wq_event_manager_threadreq;
+	if (req_tmp && workq_may_start_event_mgr_thread(wq, uth)) {
+		return req_tmp;
+	}
+
 	/*
 	 * Compute the best priority request (special or turnstile)
 	 */
 
-	pri = (uint8_t)turnstile_workq_proprietor_of_max_turnstile(wq->wq_turnstile,
+	pri = turnstile_workq_proprietor_of_max_turnstile(wq->wq_turnstile,
 	    &proprietor);
 	if (pri) {
 		struct kqworkloop *kqwl = (struct kqworkloop *)proprietor;
@@ -4384,30 +3004,10 @@
 
 	req_tmp = priority_queue_max(&wq->wq_special_queue,
 	    struct workq_threadreq_s, tr_entry);
-	if (req_tmp && pri < priority_queue_entry_sched_pri(&wq->wq_special_queue,
+	if (req_tmp && pri < priority_queue_entry_key(&wq->wq_special_queue,
 	    &req_tmp->tr_entry)) {
 		req_pri = req_tmp;
-		pri = (uint8_t)priority_queue_entry_sched_pri(&wq->wq_special_queue,
-		    &req_tmp->tr_entry);
-	}
-
-	/*
-	 * Handle the manager thread request. The special queue might yield
-	 * a higher priority, but the manager always beats the QoS world.
-	 */
-
-	req_mgr = wq->wq_event_manager_threadreq;
-	if (req_mgr && workq_may_start_event_mgr_thread(wq, uth)) {
-		uint32_t mgr_pri = wq->wq_event_manager_priority;
-
-		if (mgr_pri & _PTHREAD_PRIORITY_SCHED_PRI_FLAG) {
-			mgr_pri &= _PTHREAD_PRIORITY_SCHED_PRI_MASK;
-		} else {
-			mgr_pri = thread_workq_pri_for_qos(
-				_pthread_priority_thread_qos(mgr_pri));
-		}
-
-		return mgr_pri >= pri ? req_mgr : req_pri;
+		pri = priority_queue_entry_key(&wq->wq_special_queue, &req_tmp->tr_entry);
 	}
 
 	/*
@@ -4420,38 +3020,15 @@
 		qos = req_qos->tr_qos;
 	}
 
-	req_tmp = workq_cooperative_queue_best_req(wq, uth);
-	if (req_tmp && qos <= req_tmp->tr_qos) {
-		/*
-		 * Cooperative TR is better between overcommit and cooperative.  Note
-		 * that if qos is same between overcommit and cooperative, we choose
-		 * cooperative.
-		 *
-		 * Pick cooperative pool if it passes the admissions check
-		 */
-		if (workq_cooperative_allowance(wq, req_tmp->tr_qos, uth, true)) {
-			req_qos = req_tmp;
-			qos = req_qos->tr_qos;
-		}
-	}
-
-	/*
-	 * Compare the best QoS so far - either from overcommit or from cooperative
-	 * pool - and compare it with the constrained pool
-	 */
 	req_tmp = priority_queue_max(&wq->wq_constrained_queue,
 	    struct workq_threadreq_s, tr_entry);
 
 	if (req_tmp && qos < req_tmp->tr_qos) {
-		/*
-		 * Constrained pool is best in QoS between overcommit, cooperative
-		 * and constrained. Now check how it fairs against the priority case
-		 */
 		if (pri && pri >= thread_workq_pri_for_qos(req_tmp->tr_qos)) {
 			return req_pri;
 		}
 
-		if (workq_constrained_allowance(wq, req_tmp->tr_qos, uth, true, true)) {
+		if (workq_constrained_allowance(wq, req_tmp->tr_qos, uth, true)) {
 			/*
 			 * If the constrained thread request is the best one and passes
 			 * the admission check, pick it.
@@ -4534,29 +3111,29 @@
 		return;
 	}
 
-
 	if (uth) {
 		/*
 		 * We need to maybe override the creator we already have
 		 */
 		if (workq_thread_needs_priority_change(req, uth)) {
 			WQ_TRACE_WQ(TRACE_wq_creator_select | DBG_FUNC_NONE,
-			    wq, 1, uthread_tid(uth), req->tr_qos);
+			    wq, 1, thread_tid(uth->uu_thread), req->tr_qos, 0);
 			workq_thread_reset_pri(wq, uth, req, /*unpark*/ true);
 		}
-		assert(wq->wq_inheritor == get_machthread(uth));
+		assert(wq->wq_inheritor == uth->uu_thread);
 	} else if (wq->wq_thidlecount) {
 		/*
 		 * We need to unpark a creator thread
 		 */
 		wq->wq_creator = uth = workq_pop_idle_thread(wq, UT_WORKQ_OVERCOMMIT,
 		    &needs_wakeup);
-		/* Always reset the priorities on the newly chosen creator */
-		workq_thread_reset_pri(wq, uth, req, /*unpark*/ true);
-		workq_turnstile_update_inheritor(wq, get_machthread(uth),
+		if (workq_thread_needs_priority_change(req, uth)) {
+			workq_thread_reset_pri(wq, uth, req, /*unpark*/ true);
+		}
+		workq_turnstile_update_inheritor(wq, uth->uu_thread,
 		    TURNSTILE_INHERITOR_THREAD);
 		WQ_TRACE_WQ(TRACE_wq_creator_select | DBG_FUNC_NONE,
-		    wq, 2, uthread_tid(uth), req->tr_qos);
+		    wq, 2, thread_tid(uth->uu_thread), req->tr_qos, 0);
 		uth->uu_save.uus_workq_park_data.fulfilled_snapshot = wq->wq_fulfilled;
 		uth->uu_save.uus_workq_park_data.yields = 0;
 		if (needs_wakeup) {
@@ -4574,8 +3151,7 @@
 		} else if (!(flags & WORKQ_THREADREQ_CAN_CREATE_THREADS)) {
 			/* This can drop the workqueue lock, and take it again */
 			workq_schedule_immediate_thread_creation(wq);
-		} else if ((workq_add_new_idle_thread(p, wq,
-		    workq_unpark_continue, false, NULL) == KERN_SUCCESS)) {
+		} else if (workq_add_new_idle_thread(p, wq)) {
 			goto again;
 		} else {
 			workq_schedule_delayed_thread_creation(wq, 0);
@@ -4614,22 +3190,21 @@
 	bool schedule_creator = false;
 
 	if (__improbable(_wq_exiting(wq))) {
-		WQ_TRACE_WQ(TRACE_wq_select_threadreq | DBG_FUNC_NONE, wq, 0, 0, 0);
+		WQ_TRACE_WQ(TRACE_wq_select_threadreq | DBG_FUNC_NONE, wq, 0, 0, 0, 0);
 		goto park;
 	}
 
 	if (wq->wq_reqcount == 0) {
-		WQ_TRACE_WQ(TRACE_wq_select_threadreq | DBG_FUNC_NONE, wq, 1, 0, 0);
+		WQ_TRACE_WQ(TRACE_wq_select_threadreq | DBG_FUNC_NONE, wq, 1, 0, 0, 0);
 		goto park;
 	}
 
 	req = workq_threadreq_select(wq, uth);
 	if (__improbable(req == NULL)) {
-		WQ_TRACE_WQ(TRACE_wq_select_threadreq | DBG_FUNC_NONE, wq, 2, 0, 0);
+		WQ_TRACE_WQ(TRACE_wq_select_threadreq | DBG_FUNC_NONE, wq, 2, 0, 0, 0);
 		goto park;
 	}
 
-	struct uu_workq_policy old_pri = uth->uu_workq_pri;
 	uint8_t tr_flags = req->tr_flags;
 	struct turnstile *req_ts = kqueue_threadreq_get_turnstile(req);
 
@@ -4646,48 +3221,28 @@
 	 */
 	if (req_ts) {
 		workq_perform_turnstile_operation_locked(wq, ^{
-			turnstile_update_inheritor(req_ts, get_machthread(uth),
+			turnstile_update_inheritor(req_ts, uth->uu_thread,
 			TURNSTILE_IMMEDIATE_UPDATE | TURNSTILE_INHERITOR_THREAD);
 			turnstile_update_inheritor_complete(req_ts,
 			TURNSTILE_INTERLOCK_HELD);
 		});
 	}
 
-	/* accounting changes of aggregate thscheduled_count and thactive which has
-	 * to be paired with the workq_thread_reset_pri below so that we have
-	 * uth->uu_workq_pri match with thactive.
-	 *
-	 * This is undone when the thread parks */
 	if (is_creator) {
 		WQ_TRACE_WQ(TRACE_wq_creator_select, wq, 4, 0,
-		    uth->uu_save.uus_workq_park_data.yields);
+		    uth->uu_save.uus_workq_park_data.yields, 0);
 		wq->wq_creator = NULL;
 		_wq_thactive_inc(wq, req->tr_qos);
 		wq->wq_thscheduled_count[_wq_bucket(req->tr_qos)]++;
-	} else if (old_pri.qos_bucket != req->tr_qos) {
-		_wq_thactive_move(wq, old_pri.qos_bucket, req->tr_qos);
-	}
+	} else if (uth->uu_workq_pri.qos_bucket != req->tr_qos) {
+		_wq_thactive_move(wq, uth->uu_workq_pri.qos_bucket, req->tr_qos);
+	}
+
 	workq_thread_reset_pri(wq, uth, req, /*unpark*/ true);
 
-	/*
-	 * Make relevant accounting changes for pool specific counts.
-	 *
-	 * The schedule counts changing can affect what the next best request
-	 * for cooperative thread pool is if this request is dequeued.
-	 */
-	bool cooperative_sched_count_changed =
-	    workq_adjust_cooperative_constrained_schedule_counts(wq, uth,
-	    old_pri.qos_req, tr_flags);
-
-	if (workq_tr_is_overcommit(tr_flags)) {
-		workq_thread_set_type(uth, UT_WORKQ_OVERCOMMIT);
-	} else if (workq_tr_is_cooperative(tr_flags)) {
-		workq_thread_set_type(uth, UT_WORKQ_COOPERATIVE);
-	} else {
-		workq_thread_set_type(uth, 0);
-	}
-
-	if (__improbable(thread_unfreeze_base_pri(get_machthread(uth)) && !is_creator)) {
+	thread_unfreeze_base_pri(uth->uu_thread);
+#if 0 // <rdar://problem/55259863> to turn this back on
+	if (__improbable(thread_unfreeze_base_pri(uth->uu_thread) && !is_creator)) {
 		if (req_ts) {
 			workq_perform_turnstile_operation_locked(wq, ^{
 				turnstile_update_inheritor(req_ts, wq->wq_turnstile,
@@ -4696,36 +3251,19 @@
 				TURNSTILE_INTERLOCK_HELD);
 			});
 		}
-		WQ_TRACE_WQ(TRACE_wq_select_threadreq | DBG_FUNC_NONE, wq, 3, 0, 0);
-
-		/*
-		 * If a cooperative thread was the one which picked up the manager
-		 * thread request, we need to reevaluate the cooperative pool before
-		 * it goes and parks.
-		 *
-		 * For every other of thread request that it picks up, the logic in
-		 * workq_threadreq_select should have done this refresh.
-		 * See workq_push_idle_thread.
-		 */
-		if (cooperative_sched_count_changed) {
-			if (req->tr_qos == WORKQ_THREAD_QOS_MANAGER) {
-				_wq_cooperative_queue_refresh_best_req_qos(wq);
-			}
-		}
+		WQ_TRACE_WQ(TRACE_wq_select_threadreq | DBG_FUNC_NONE, wq, 3, 0, 0, 0);
 		goto park_thawed;
 	}
+#endif
 
 	/*
 	 * We passed all checks, dequeue the request, bind to it, and set it up
 	 * to return to user.
 	 */
 	WQ_TRACE_WQ(TRACE_wq_thread_logical_run | DBG_FUNC_START, wq,
-	    workq_trace_req_id(req), tr_flags, 0);
+	    workq_trace_req_id(req), 0, 0, 0);
 	wq->wq_fulfilled++;
-	schedule_creator = workq_threadreq_dequeue(wq, req,
-	    cooperative_sched_count_changed);
-
-	workq_thread_reset_cpupercent(req, uth);
+	schedule_creator = workq_threadreq_dequeue(wq, req);
 
 	if (tr_flags & (WORKQ_TR_FLAG_KEVENT | WORKQ_TR_FLAG_WORKLOOP)) {
 		kqueue_threadreq_bind_prepost(p, req, uth);
@@ -4734,19 +3272,23 @@
 		req = NULL;
 	}
 
+	workq_thread_reset_cpupercent(req, uth);
 	if (uth->uu_workq_flags & UT_WORKQ_NEW) {
 		uth->uu_workq_flags ^= UT_WORKQ_NEW;
 		setup_flags |= WQ_SETUP_FIRST_USE;
 	}
-
-	/* If one of the following is true, call workq_schedule_creator (which also
-	 * adjusts priority of existing creator):
-	 *
-	 *	  - We are the creator currently so the wq may need a new creator
-	 *	  - The request we're binding to is the highest priority one, existing
-	 *	  creator's priority might need to be adjusted to reflect the next
-	 *	  highest TR
-	 */
+	if (tr_flags & WORKQ_TR_FLAG_OVERCOMMIT) {
+		if ((uth->uu_workq_flags & UT_WORKQ_OVERCOMMIT) == 0) {
+			uth->uu_workq_flags |= UT_WORKQ_OVERCOMMIT;
+			wq->wq_constrained_threads_scheduled--;
+		}
+	} else {
+		if ((uth->uu_workq_flags & UT_WORKQ_OVERCOMMIT) != 0) {
+			uth->uu_workq_flags &= ~UT_WORKQ_OVERCOMMIT;
+			wq->wq_constrained_threads_scheduled++;
+		}
+	}
+
 	if (is_creator || schedule_creator) {
 		/* This can drop the workqueue lock, and take it again */
 		workq_schedule_creator(p, wq, WORKQ_THREADREQ_CAN_CREATE_THREADS);
@@ -4764,41 +3306,28 @@
 	uint32_t upcall_flags = WQ_FLAG_THREAD_NEWSPI;
 	if (uth->uu_workq_pri.qos_bucket == WORKQ_THREAD_QOS_MANAGER) {
 		upcall_flags |= WQ_FLAG_THREAD_EVENT_MANAGER;
-	} else if (workq_tr_is_overcommit(tr_flags)) {
+	} else if (tr_flags & WORKQ_TR_FLAG_OVERCOMMIT) {
 		upcall_flags |= WQ_FLAG_THREAD_OVERCOMMIT;
-	} else if (workq_tr_is_cooperative(tr_flags)) {
-		upcall_flags |= WQ_FLAG_THREAD_COOPERATIVE;
 	}
 	if (tr_flags & WORKQ_TR_FLAG_KEVENT) {
 		upcall_flags |= WQ_FLAG_THREAD_KEVENT;
-		assert((upcall_flags & WQ_FLAG_THREAD_COOPERATIVE) == 0);
-	}
-
+	}
 	if (tr_flags & WORKQ_TR_FLAG_WORKLOOP) {
 		upcall_flags |= WQ_FLAG_THREAD_WORKLOOP | WQ_FLAG_THREAD_KEVENT;
 	}
 	uth->uu_save.uus_workq_park_data.upcall_flags = upcall_flags;
 
 	if (tr_flags & (WORKQ_TR_FLAG_KEVENT | WORKQ_TR_FLAG_WORKLOOP)) {
-		kqueue_threadreq_bind_commit(p, get_machthread(uth));
-	} else {
-#if CONFIG_PREADOPT_TG
-		/*
-		 * The thread may have a preadopt thread group on it already because it
-		 * got tagged with it as a creator thread. So we need to make sure to
-		 * clear that since we don't have preadoption for anonymous thread
-		 * requests
-		 */
-		thread_set_preadopt_thread_group(get_machthread(uth), NULL);
-#endif
-	}
-
+		kqueue_threadreq_bind_commit(p, uth->uu_thread);
+	}
 	workq_setup_and_run(p, uth, setup_flags);
 	__builtin_unreachable();
 
 park:
-	thread_unfreeze_base_pri(get_machthread(uth));
+	thread_unfreeze_base_pri(uth->uu_thread);
+#if 0 // <rdar://problem/55259863>
 park_thawed:
+#endif
 	workq_park_and_unlock(p, wq, uth, setup_flags);
 }
 
@@ -4834,14 +3363,13 @@
 		workq_threadreq_t req = uth->uu_save.uus_workq_park_data.thread_request;
 		workq_unlock(wq);
 		WQ_TRACE_WQ(TRACE_wq_thread_logical_run | DBG_FUNC_START, wq,
-		    VM_KERNEL_ADDRHIDE(req), 0, 0);
+		    VM_KERNEL_ADDRHIDE(req), 0, 0, 0);
 		(void)req;
-
 		workq_setup_and_run(p, uth, setup_flags);
 		__builtin_unreachable();
 	}
 
-	thread_freeze_base_pri(get_machthread(uth));
+	thread_freeze_base_pri(uth->uu_thread);
 	workq_select_threadreq_or_park_and_unlock(p, wq, uth, setup_flags);
 }
 
@@ -4863,17 +3391,17 @@
 	if (wq->wq_fulfilled - snapshot > conc) {
 		/* we fulfilled more than NCPU requests since being dispatched */
 		WQ_TRACE_WQ(TRACE_wq_creator_yield, wq, 1,
-		    wq->wq_fulfilled, snapshot);
+		    wq->wq_fulfilled, snapshot, 0);
 		return true;
 	}
 
-	for (uint8_t i = _wq_bucket(qos); i < WORKQ_NUM_QOS_BUCKETS; i++) {
+	for (int i = _wq_bucket(qos); i < WORKQ_NUM_QOS_BUCKETS; i++) {
 		cnt += wq->wq_thscheduled_count[i];
 	}
 	if (conc <= cnt) {
 		/* We fulfilled requests and have more than NCPU scheduled threads */
 		WQ_TRACE_WQ(TRACE_wq_creator_yield, wq, 2,
-		    wq->wq_fulfilled, snapshot);
+		    wq->wq_fulfilled, snapshot, 0);
 		return true;
 	}
 
@@ -4881,7 +3409,7 @@
 }
 
 /**
- * parked idle thread wakes up
+ * parked thread wakes up
  */
 __attribute__((noreturn, noinline))
 static void
@@ -4940,8 +3468,8 @@
 static void
 workq_setup_and_run(proc_t p, struct uthread *uth, int setup_flags)
 {
-	thread_t th = get_machthread(uth);
-	vm_map_t vmap = get_task_map(proc_task(p));
+	thread_t th = uth->uu_thread;
+	vm_map_t vmap = get_task_map(p->task);
 
 	if (setup_flags & WQ_SETUP_CLEAR_VOUCHER) {
 		/*
@@ -4953,9 +3481,6 @@
 		 * Those two places are sufficient to ensure we always reset it before
 		 * it goes back out to user space, but be careful to not break that
 		 * guarantee.
-		 *
-		 * Note that setting the voucher to NULL will not clear the preadoption
-		 * thread group on this thread
 		 */
 		__assert_only kern_return_t kr;
 		kr = thread_set_voucher_name(MACH_PORT_NULL);
@@ -4985,20 +3510,10 @@
 	}
 
 	if (uth->uu_workq_thport == MACH_PORT_NULL) {
-		/* convert_thread_to_port_immovable() consumes a reference */
+		/* convert_thread_to_port() consumes a reference */
 		thread_reference(th);
-		/* Convert to immovable thread port, then pin the entry */
-		uth->uu_workq_thport = ipc_port_copyout_send_pinned(
-			convert_thread_to_port_immovable(th),
-			get_task_ipcspace(proc_task(p)));
-	}
-
-	/* Thread has been set up to run, arm its next workqueue quantum or disarm
-	 * if it is no longer supporting that */
-	if (thread_supports_cooperative_workqueue(th)) {
-		thread_arm_workqueue_quantum(th);
-	} else {
-		thread_disarm_workqueue_quantum(th);
+		ipc_port_t port = convert_thread_to_port(th);
+		uth->uu_workq_thport = ipc_port_copyout_send(port, get_task_ipcspace(p->task));
 	}
 
 	/*
@@ -5006,177 +3521,11 @@
 	 * onto the stack, sets up the thread state and then returns to userspace.
 	 */
 	WQ_TRACE_WQ(TRACE_wq_runthread | DBG_FUNC_START,
-	    proc_get_wqptr_fast(p), 0, 0, 0);
-
-	if (workq_thread_is_cooperative(uth)) {
-		thread_sched_call(th, NULL);
-	} else {
-		thread_sched_call(th, workq_sched_callback);
-	}
-
+	    proc_get_wqptr_fast(p), 0, 0, 0, 0);
+	thread_sched_call(th, workq_sched_callback);
 	pthread_functions->workq_setup_thread(p, th, vmap, uth->uu_workq_stackaddr,
 	    uth->uu_workq_thport, 0, setup_flags, upcall_flags);
 
-	__builtin_unreachable();
-}
-
-/**
- * A wrapper around workq_setup_and_run for permanently bound thread.
- */
-__attribute__((noreturn, noinline))
-static void
-workq_bound_thread_setup_and_run(struct uthread *uth, int setup_flags)
-{
-	struct workq_threadreq_s * kqr = uth->uu_kqr_bound;
-
-	uint32_t upcall_flags = (WQ_FLAG_THREAD_NEWSPI |
-	    WQ_FLAG_THREAD_WORKLOOP | WQ_FLAG_THREAD_KEVENT);
-	if (workq_tr_is_overcommit(kqr->tr_flags)) {
-		workq_thread_set_type(uth, UT_WORKQ_OVERCOMMIT);
-		upcall_flags |= WQ_FLAG_THREAD_OVERCOMMIT;
-	}
-	uth->uu_save.uus_workq_park_data.upcall_flags = upcall_flags;
-
-	/*
-	 * Increment thactive since we've decided this thread should go to
-	 * userspace. The scheduler callback is set in workq_setup_and_run.
-	 */
-	proc_t p = current_proc();
-	struct workqueue *wq = proc_get_wqptr_fast(p);
-	_wq_thactive_inc(wq, uth->uu_workq_pri.qos_bucket);
-
-	workq_setup_and_run(p, uth, setup_flags);
-	__builtin_unreachable();
-}
-
-/**
- * A parked bound thread wakes up for the first time.
- */
-__attribute__((noreturn, noinline))
-static void
-workq_bound_thread_initialize_and_unpark_continue(void *parameter __unused,
-    wait_result_t wr)
-{
-	/*
-	 * Locking model for accessing uu_workq_flags :
-	 *
-	 * The concurrent access to uu_workq_flags is synchronized with workq lock
-	 * until a thread gets permanently bound to a kqwl. Post that, kqlock
-	 * is used for subsequent synchronizations. This gives us a significant
-	 * benefit by avoiding having to take a process wide workq lock on every
-	 * wakeup of the bound thread.
-	 * This flip in locking model is tracked with UT_WORKQ_PERMANENT_BIND flag.
-	 *
-	 * There is one more optimization we can perform for when the thread is
-	 * awakened for running (i.e THREAD_AWAKENED) until it parks.
-	 * During this window, we know KQ_SLEEP bit is reset so there should not
-	 * be any concurrent attempts to modify uu_workq_flags by
-	 * kqworkloop_bound_thread_wakeup because the thread is already "awake".
-	 * So we can safely access uu_workq_flags within this window without having
-	 * to take kqlock. This KQ_SLEEP is later set by the bound thread under
-	 * kqlock on its way to parking.
-	 */
-	struct uthread *uth = get_bsdthread_info(current_thread());
-
-	if (__probable(wr == THREAD_AWAKENED)) {
-		/* At most one flag. */
-		assert((uth->uu_workq_flags & (UT_WORKQ_RUNNING | UT_WORKQ_DYING))
-		    != (UT_WORKQ_RUNNING | UT_WORKQ_DYING));
-
-		assert(workq_thread_is_permanently_bound(uth));
-
-		if (uth->uu_workq_flags & UT_WORKQ_RUNNING) {
-			assert(uth->uu_workq_flags & UT_WORKQ_NEW);
-			uth->uu_workq_flags &= ~UT_WORKQ_NEW;
-
-			struct workq_threadreq_s * kqr = uth->uu_kqr_bound;
-			if (kqr->tr_work_interval) {
-				kern_return_t kr;
-				kr = kern_work_interval_explicit_join(get_machthread(uth),
-				    kqr->tr_work_interval);
-				/*
-				 * The work interval functions requires to be called on the
-				 * current thread. If we fail here, we record the fact and
-				 * continue.
-				 * In the future, we can preflight checking that this join will
-				 * always be successful when the paird kqwl is configured; but,
-				 * for now, this should be a rare case (e.g. if you have passed
-				 * invalid arguments to the join).
-				 */
-				if (kr == KERN_SUCCESS) {
-					uth->uu_workq_flags |= UT_WORKQ_WORK_INTERVAL_JOINED;
-					/* Thread and kqwl both have +1 ref on the work interval. */
-				} else {
-					uth->uu_workq_flags |= UT_WORKQ_WORK_INTERVAL_FAILED;
-				}
-			}
-			workq_thread_reset_cpupercent(kqr, uth);
-			workq_bound_thread_setup_and_run(uth, WQ_SETUP_FIRST_USE);
-			__builtin_unreachable();
-		} else {
-			/*
-			 * The permanently bound kqworkloop is getting destroyed so we
-			 * are woken up to cleanly unbind ourselves from it and terminate.
-			 * See KQ_WORKLOOP_DESTROY -> workq_kern_bound_thread_wakeup.
-			 *
-			 * The actual full unbind happens from
-			 * uthread_cleanup -> kqueue_threadreq_unbind.
-			 */
-			assert(uth->uu_workq_flags & UT_WORKQ_DYING);
-		}
-	} else {
-		/*
-		 * The process is getting terminated so we are woken up to die.
-		 * E.g. SIGKILL'd.
-		 */
-		assert(wr == THREAD_INTERRUPTED);
-		/*
-		 * It is possible we started running as the process is aborted
-		 * due to termination; but, workq_kern_threadreq_permanent_bind
-		 * has not had a chance to bind us to the kqwl yet.
-		 *
-		 * We synchronize with it using workq lock.
-		 */
-		proc_t p = current_proc();
-		struct workqueue *wq = proc_get_wqptr_fast(p);
-		workq_lock_spin(wq);
-		assert(workq_thread_is_permanently_bound(uth));
-		workq_unlock(wq);
-
-		/*
-		 * We do the bind commit ourselves if workq_kern_threadreq_permanent_bind
-		 * has not done it for us yet so our state is aligned with what the
-		 * termination path below expects.
-		 */
-		kqueue_threadreq_bind_commit(p, get_machthread(uth));
-	}
-	workq_kern_bound_thread_terminate(uth->uu_kqr_bound);
-	__builtin_unreachable();
-}
-
-/**
- * A parked bound thread wakes up. Not the first time.
- */
-__attribute__((noreturn, noinline))
-static void
-workq_bound_thread_unpark_continue(void *parameter __unused, wait_result_t wr)
-{
-	struct uthread *uth = get_bsdthread_info(current_thread());
-	assert(workq_thread_is_permanently_bound(uth));
-
-	if (__probable(wr == THREAD_AWAKENED)) {
-		/* At most one flag. */
-		assert((uth->uu_workq_flags & (UT_WORKQ_RUNNING | UT_WORKQ_DYING))
-		    != (UT_WORKQ_RUNNING | UT_WORKQ_DYING));
-		if (uth->uu_workq_flags & UT_WORKQ_RUNNING) {
-			workq_bound_thread_setup_and_run(uth, WQ_SETUP_NONE);
-		} else {
-			assert(uth->uu_workq_flags & UT_WORKQ_DYING);
-		}
-	} else {
-		assert(wr == THREAD_INTERRUPTED);
-	}
-	workq_kern_bound_thread_terminate(uth->uu_kqr_bound);
 	__builtin_unreachable();
 }
 
@@ -5224,17 +3573,6 @@
 		pwqinfo->pwq_state |= WQ_EXCEEDED_TOTAL_THREAD_LIMIT;
 	}
 
-	uint64_t total_cooperative_threads;
-	total_cooperative_threads = workq_num_cooperative_threads_scheduled_total(wq);
-	if ((total_cooperative_threads == wq_cooperative_queue_max_size(wq)) &&
-	    workq_has_cooperative_thread_requests(wq)) {
-		pwqinfo->pwq_state |= WQ_EXCEEDED_COOPERATIVE_THREAD_LIMIT;
-	}
-
-	if (wq->wq_exceeded_active_constrained_thread_limit) {
-		pwqinfo->pwq_state |= WQ_EXCEEDED_ACTIVE_CONSTRAINED_THREAD_LIMIT;
-	}
-
 	workq_unlock(wq);
 	return error;
 }
@@ -5265,22 +3603,16 @@
 	return TRUE;
 }
 
-uint64_t
-workqueue_get_task_ss_flags_from_pwq_state_kdp(void * v)
+uint32_t
+workqueue_get_pwq_state_kdp(void * v)
 {
 	static_assert((WQ_EXCEEDED_CONSTRAINED_THREAD_LIMIT << 17) ==
 	    kTaskWqExceededConstrainedThreadLimit);
 	static_assert((WQ_EXCEEDED_TOTAL_THREAD_LIMIT << 17) ==
 	    kTaskWqExceededTotalThreadLimit);
 	static_assert((WQ_FLAGS_AVAILABLE << 17) == kTaskWqFlagsAvailable);
-	static_assert(((uint64_t)WQ_EXCEEDED_COOPERATIVE_THREAD_LIMIT << 34) ==
-	    (uint64_t)kTaskWqExceededCooperativeThreadLimit);
-	static_assert(((uint64_t)WQ_EXCEEDED_ACTIVE_CONSTRAINED_THREAD_LIMIT << 34) ==
-	    (uint64_t)kTaskWqExceededActiveConstrainedThreadLimit);
 	static_assert((WQ_FLAGS_AVAILABLE | WQ_EXCEEDED_TOTAL_THREAD_LIMIT |
-	    WQ_EXCEEDED_CONSTRAINED_THREAD_LIMIT |
-	    WQ_EXCEEDED_COOPERATIVE_THREAD_LIMIT |
-	    WQ_EXCEEDED_ACTIVE_CONSTRAINED_THREAD_LIMIT) == 0x1F);
+	    WQ_EXCEEDED_CONSTRAINED_THREAD_LIMIT) == 0x7);
 
 	if (v == NULL) {
 		return 0;
@@ -5289,38 +3621,35 @@
 	proc_t p = v;
 	struct workqueue *wq = proc_get_wqptr(p);
 
-	if (wq == NULL || workq_lock_is_acquired_kdp(wq)) {
+	if (wq == NULL || workq_lock_spin_is_acquired_kdp(wq)) {
 		return 0;
 	}
 
-	uint64_t ss_flags = kTaskWqFlagsAvailable;
+	uint32_t pwq_state = WQ_FLAGS_AVAILABLE;
 
 	if (wq->wq_constrained_threads_scheduled >= wq_max_constrained_threads) {
-		ss_flags |= kTaskWqExceededConstrainedThreadLimit;
+		pwq_state |= WQ_EXCEEDED_CONSTRAINED_THREAD_LIMIT;
 	}
 
 	if (wq->wq_nthreads >= wq_max_threads) {
-		ss_flags |= kTaskWqExceededTotalThreadLimit;
-	}
-
-	uint64_t total_cooperative_threads;
-	total_cooperative_threads = workq_num_cooperative_threads_scheduled_to_qos_internal(wq,
-	    WORKQ_THREAD_QOS_MIN);
-	if ((total_cooperative_threads == wq_cooperative_queue_max_size(wq)) &&
-	    workq_has_cooperative_thread_requests(wq)) {
-		ss_flags |= kTaskWqExceededCooperativeThreadLimit;
-	}
-
-	if (wq->wq_exceeded_active_constrained_thread_limit) {
-		ss_flags |= kTaskWqExceededActiveConstrainedThreadLimit;
-	}
-
-	return ss_flags;
+		pwq_state |= WQ_EXCEEDED_TOTAL_THREAD_LIMIT;
+	}
+
+	return pwq_state;
 }
 
 void
 workq_init(void)
 {
+	workq_lck_grp_attr = lck_grp_attr_alloc_init();
+	workq_lck_attr = lck_attr_alloc_init();
+	workq_lck_grp = lck_grp_alloc_init("workq", workq_lck_grp_attr);
+
+	workq_zone_workqueue = zinit(sizeof(struct workqueue),
+	    1024 * sizeof(struct workqueue), 8192, "workq.wq");
+	workq_zone_threadreq = zinit(sizeof(struct workq_threadreq_s),
+	    1024 * sizeof(struct workq_threadreq_s), 8192, "workq.threadreq");
+
 	clock_interval_to_absolutetime_interval(wq_stalled_window.usecs,
 	    NSEC_PER_USEC, &wq_stalled_window.abstime);
 	clock_interval_to_absolutetime_interval(wq_reduce_pool_window.usecs,