 @@ -1,1037 +1,1038 @@
-/*	$NetBSD: kern_threadpool.c,v 1.8 2018/12/26 21:18:51 thorpej Exp $	*/
+/*	$NetBSD: kern_threadpool.c,v 1.9 2018/12/26 21:25:51 thorpej Exp $	*/
 /*-
  * Copyright (c) 2014, 2018 The NetBSD Foundation, Inc.
  * All rights reserved.
+ *
  * This code is derived from software contributed to The NetBSD Foundation
  * by Taylor R. Campbell and Jason R. Thorpe.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
+ *
  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  */
 /*
  * Thread pools.
+ *
  * A thread pool is a collection of worker threads idle or running
  * jobs, together with an overseer thread that does not run jobs but
  * can be given jobs to assign to a worker thread.  Scheduling a job in
  * a thread pool does not allocate or even sleep at all, except perhaps
  * on an adaptive lock, unlike kthread_create.  Jobs reuse threads, so
  * they do not incur the expense of creating and destroying kthreads
  * unless there is not much work to be done.
+ *
  * A per-CPU thread pool (threadpool_percpu) is a collection of thread
  * pools, one per CPU bound to that CPU.  For each priority level in
  * use, there is one shared unbound thread pool (i.e., pool of threads
  * not bound to any CPU) and one shared per-CPU thread pool.
+ *
  * To use the unbound thread pool at priority pri, call
  * threadpool_get(&pool, pri).  When you're done, call
  * threadpool_put(pool, pri).
+ *
  * To use the per-CPU thread pools at priority pri, call
  * threadpool_percpu_get(&pool_percpu, pri), and then use the thread
  * pool returned by threadpool_percpu_ref(pool_percpu) for the current
  * CPU, or by threadpool_percpu_ref_remote(pool_percpu, ci) for another
  * CPU.  When you're done, call threadpool_percpu_put(pool_percpu,
  * pri).
+ *
  * +--MACHINE-----------------------------------------------+
  * | +--CPU 0-------+ +--CPU 1-------+     +--CPU n-------+ |
  * | | <overseer 0> | | <overseer 1> | ... | <overseer n> | |
  * | | <idle 0a>    | | <running 1a> | ... | <idle na>    | |
  * | | <running 0b> | | <running 1b> | ... | <idle nb>    | |
  * | | .            | | .            | ... | .            | |
  * | | .            | | .            | ... | .            | |
  * | | .            | | .            | ... | .            | |
  * | +--------------+ +--------------+     +--------------+ |
  * |            +--unbound---------+                        |
  * |            | <overseer n+1>   |                        |
  * |            | <idle (n+1)a>    |                        |
  * |            | <running (n+1)b> |                        |
  * |            +------------------+                        |
  * +--------------------------------------------------------+
+ *
  * XXX Why one overseer per CPU?  I did that originally to avoid
  * touching remote CPUs' memory when scheduling a job, but that still
  * requires interprocessor synchronization.  Perhaps we could get by
  * with a single overseer thread, at the expense of another pointer in
  * struct threadpool_job to identify the CPU on which it must run
  * in order for the overseer to schedule it correctly.
  */
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_threadpool.c,v 1.8 2018/12/26 21:18:51 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_threadpool.c,v 1.9 2018/12/26 21:25:51 thorpej Exp $");
 #include <sys/types.h>
 #include <sys/param.h>
 #include <sys/atomic.h>
 #include <sys/condvar.h>
 #include <sys/cpu.h>
 #include <sys/kernel.h>
 #include <sys/kmem.h>
 #include <sys/kthread.h>
 #include <sys/mutex.h>
 #include <sys/once.h>
 #include <sys/percpu.h>
 #include <sys/pool.h>
 #include <sys/proc.h>
 #include <sys/queue.h>
 #include <sys/systm.h>
 #include <sys/threadpool.h>
 static ONCE_DECL(threadpool_init_once)
 #define	THREADPOOL_INIT()					\
 do {								\
 	int threadpool_init_error __diagused =			\
 	    RUN_ONCE(&threadpool_init_once, threadpools_init);	\
 	KASSERT(threadpool_init_error == 0);			\
 } while (/*CONSTCOND*/0)
 /* Data structures */
 TAILQ_HEAD(job_head, threadpool_job);
 TAILQ_HEAD(thread_head, threadpool_thread);
 struct threadpool_thread {
 	struct lwp			*tpt_lwp;
 	struct threadpool		*tpt_pool;
 	struct threadpool_job		*tpt_job;
 	kcondvar_t			tpt_cv;
 	TAILQ_ENTRY(threadpool_thread)	tpt_entry;
 };
 struct threadpool {
 	kmutex_t			tp_lock;
 	struct threadpool_thread	tp_overseer;
 	struct job_head			tp_jobs;
 	struct thread_head		tp_idle_threads;
 	uint64_t			tp_refcnt;
 	int				tp_flags;
 #define	THREADPOOL_DYING	0x01
 	struct cpu_info			*tp_cpu;
 	pri_t				tp_pri;
 };
 static void	threadpool_hold(struct threadpool *);
 static void	threadpool_rele(struct threadpool *);
 static int	threadpool_percpu_create(struct threadpool_percpu **, pri_t);
 static void	threadpool_percpu_destroy(struct threadpool_percpu *);
 static void	threadpool_job_dead(struct threadpool_job *);
 static int	threadpool_job_hold(struct threadpool_job *);
 static void	threadpool_job_rele(struct threadpool_job *);
 static void	threadpool_overseer_thread(void *) __dead;
 static void	threadpool_thread(void *) __dead;
 static pool_cache_t	threadpool_thread_pc __read_mostly;
 static kmutex_t		threadpools_lock __cacheline_aligned;
 	/* Idle out threads after 30 seconds */
 #define	THREADPOOL_IDLE_TICKS	mstohz(30 * 1000)
 struct threadpool_unbound {
 	struct threadpool		tpu_pool;
 	/* protected by threadpools_lock */
 	LIST_ENTRY(threadpool_unbound)	tpu_link;
 	uint64_t			tpu_refcnt;
 };
 static LIST_HEAD(, threadpool_unbound) unbound_threadpools;
 static struct threadpool_unbound *
 threadpool_lookup_unbound(pri_t pri)
+{
 	struct threadpool_unbound *tpu;
 	LIST_FOREACH(tpu, &unbound_threadpools, tpu_link) {
 		if (tpu->tpu_pool.tp_pri == pri)
 			return tpu;
+	}
 	return NULL;
+}
 static void
 threadpool_insert_unbound(struct threadpool_unbound *tpu)
+{
 	KASSERT(threadpool_lookup_unbound(tpu->tpu_pool.tp_pri) == NULL);
 	LIST_INSERT_HEAD(&unbound_threadpools, tpu, tpu_link);
+}
 static void
 threadpool_remove_unbound(struct threadpool_unbound *tpu)
+{
 	KASSERT(threadpool_lookup_unbound(tpu->tpu_pool.tp_pri) == tpu);
 	LIST_REMOVE(tpu, tpu_link);
+}
 struct threadpool_percpu {
 	percpu_t *			tpp_percpu;
 	pri_t				tpp_pri;
 	/* protected by threadpools_lock */
 	LIST_ENTRY(threadpool_percpu)	tpp_link;
 	uint64_t			tpp_refcnt;
 };
 static LIST_HEAD(, threadpool_percpu) percpu_threadpools;
 static struct threadpool_percpu *
 threadpool_lookup_percpu(pri_t pri)
+{
 	struct threadpool_percpu *tpp;
 	LIST_FOREACH(tpp, &percpu_threadpools, tpp_link) {
 		if (tpp->tpp_pri == pri)
 			return tpp;
+	}
 	return NULL;
+}
 static void
 threadpool_insert_percpu(struct threadpool_percpu *tpp)
+{
 	KASSERT(threadpool_lookup_percpu(tpp->tpp_pri) == NULL);
 	LIST_INSERT_HEAD(&percpu_threadpools, tpp, tpp_link);
+}
 static void
 threadpool_remove_percpu(struct threadpool_percpu *tpp)
+{
 	KASSERT(threadpool_lookup_percpu(tpp->tpp_pri) == tpp);
 	LIST_REMOVE(tpp, tpp_link);
+}
 #ifdef THREADPOOL_VERBOSE
 #define	TP_LOG(x)		printf x
 #else
 #define	TP_LOG(x)		/* nothing */
 #endif /* THREADPOOL_VERBOSE */
 static int
 threadpools_init(void)
+{
 	threadpool_thread_pc =
 	    pool_cache_init(sizeof(struct threadpool_thread), 0, 0, 0,
 		"thplthrd", NULL, IPL_NONE, NULL, NULL, NULL);
 	LIST_INIT(&unbound_threadpools);
 	LIST_INIT(&percpu_threadpools);
 	mutex_init(&threadpools_lock, MUTEX_DEFAULT, IPL_NONE);
 	TP_LOG(("%s: sizeof(threadpool_job) = %zu\n",
 	    __func__, sizeof(struct threadpool_job)));
 	return 0;
+}
 /* Thread pool creation */
 static bool
 threadpool_pri_is_valid(pri_t pri)
+{
 	return (pri == PRI_NONE || (pri >= PRI_USER && pri < PRI_COUNT));
+}
 static int
 threadpool_create(struct threadpool *const pool, struct cpu_info *ci,
     pri_t pri)
+{
 	struct lwp *lwp;
 	int ktflags;
 	int error;
 	KASSERT(threadpool_pri_is_valid(pri));
 	mutex_init(&pool->tp_lock, MUTEX_DEFAULT, IPL_VM);
 	/* XXX overseer */
 	TAILQ_INIT(&pool->tp_jobs);
 	TAILQ_INIT(&pool->tp_idle_threads);
 	pool->tp_refcnt = 1;		/* overseer's reference */
 	pool->tp_flags = 0;
 	pool->tp_cpu = ci;
 	pool->tp_pri = pri;
 	pool->tp_overseer.tpt_lwp = NULL;
 	pool->tp_overseer.tpt_pool = pool;
 	pool->tp_overseer.tpt_job = NULL;
 	cv_init(&pool->tp_overseer.tpt_cv, "poolover");
 	ktflags = 0;
 	ktflags |= KTHREAD_MPSAFE;
 	if (pri < PRI_KERNEL)
 		ktflags |= KTHREAD_TS;
 	error = kthread_create(pri, ktflags, ci, &threadpool_overseer_thread,
 	    &pool->tp_overseer, &lwp,
 	    "pooloverseer/%d@%d", (ci ? cpu_index(ci) : -1), (int)pri);
 	if (error)
 		goto fail0;
 	mutex_spin_enter(&pool->tp_lock);
 	pool->tp_overseer.tpt_lwp = lwp;
 	cv_broadcast(&pool->tp_overseer.tpt_cv);
 	mutex_spin_exit(&pool->tp_lock);
 	return 0;
 fail0:	KASSERT(error);
 	KASSERT(pool->tp_overseer.tpt_job == NULL);
 	KASSERT(pool->tp_overseer.tpt_pool == pool);
 	KASSERT(pool->tp_flags == 0);
 	KASSERT(pool->tp_refcnt == 0);
 	KASSERT(TAILQ_EMPTY(&pool->tp_idle_threads));
 	KASSERT(TAILQ_EMPTY(&pool->tp_jobs));
 	KASSERT(!cv_has_waiters(&pool->tp_overseer.tpt_cv));
 	cv_destroy(&pool->tp_overseer.tpt_cv);
 	mutex_destroy(&pool->tp_lock);
 	return error;
+}
 /* Thread pool destruction */
 static void
 threadpool_destroy(struct threadpool *pool)
+{
 	struct threadpool_thread *thread;
 	/* Mark the pool dying and wait for threads to commit suicide.  */
 	mutex_spin_enter(&pool->tp_lock);
 	KASSERT(TAILQ_EMPTY(&pool->tp_jobs));
 	pool->tp_flags |= THREADPOOL_DYING;
 	cv_broadcast(&pool->tp_overseer.tpt_cv);
 	TAILQ_FOREACH(thread, &pool->tp_idle_threads, tpt_entry)
 		cv_broadcast(&thread->tpt_cv);
 	while (0 < pool->tp_refcnt) {
 		TP_LOG(("%s: draining %u references...\n", __func__,
 		    pool->tp_refcnt));
 		cv_wait(&pool->tp_overseer.tpt_cv, &pool->tp_lock);
+	}
 	mutex_spin_exit(&pool->tp_lock);
 	KASSERT(pool->tp_overseer.tpt_job == NULL);
 	KASSERT(pool->tp_overseer.tpt_pool == pool);
 	KASSERT(pool->tp_flags == THREADPOOL_DYING);
 	KASSERT(pool->tp_refcnt == 0);
 	KASSERT(TAILQ_EMPTY(&pool->tp_idle_threads));
 	KASSERT(TAILQ_EMPTY(&pool->tp_jobs));
 	KASSERT(!cv_has_waiters(&pool->tp_overseer.tpt_cv));
 	cv_destroy(&pool->tp_overseer.tpt_cv);
 	mutex_destroy(&pool->tp_lock);
+}
 static void
 threadpool_hold(struct threadpool *pool)
+{
 	KASSERT(mutex_owned(&pool->tp_lock));
 	pool->tp_refcnt++;
 	KASSERT(pool->tp_refcnt != 0);
+}
 static void
 threadpool_rele(struct threadpool *pool)
+{
 	KASSERT(mutex_owned(&pool->tp_lock));
 	KASSERT(0 < pool->tp_refcnt);
 	if (--pool->tp_refcnt == 0)
 		cv_broadcast(&pool->tp_overseer.tpt_cv);
+}
 /* Unbound thread pools */
 int
 threadpool_get(struct threadpool **poolp, pri_t pri)
+{
 	struct threadpool_unbound *tpu, *tmp = NULL;
 	int error;
 	THREADPOOL_INIT();
 	ASSERT_SLEEPABLE();
 	if (! threadpool_pri_is_valid(pri))
 		return EINVAL;
 	mutex_enter(&threadpools_lock);
 	tpu = threadpool_lookup_unbound(pri);
 	if (tpu == NULL) {
 		mutex_exit(&threadpools_lock);
 		TP_LOG(("%s: No pool for pri=%d, creating one.\n",
-			__func__, (int)pri));
+		    __func__, (int)pri));
 		tmp = kmem_zalloc(sizeof(*tmp), KM_SLEEP);
 		error = threadpool_create(&tmp->tpu_pool, NULL, pri);
 		if (error) {
 			kmem_free(tmp, sizeof(*tmp));
 			return error;
+		}
 		mutex_enter(&threadpools_lock);
 		tpu = threadpool_lookup_unbound(pri);
 		if (tpu == NULL) {
 			TP_LOG(("%s: Won the creation race for pri=%d.\n",
-				__func__, (int)pri));
+			    __func__, (int)pri));
 			tpu = tmp;
 			tmp = NULL;
 			threadpool_insert_unbound(tpu);
+		}
+	}
 	KASSERT(tpu != NULL);
 	tpu->tpu_refcnt++;
 	KASSERT(tpu->tpu_refcnt != 0);
 	mutex_exit(&threadpools_lock);
 	if (tmp != NULL) {
 		threadpool_destroy(&tmp->tpu_pool);
 		kmem_free(tmp, sizeof(*tmp));
+	}
 	KASSERT(tpu != NULL);
 	*poolp = &tpu->tpu_pool;
 	return 0;
+}
 void
 threadpool_put(struct threadpool *pool, pri_t pri)
+{
 	struct threadpool_unbound *tpu =
 	    container_of(pool, struct threadpool_unbound, tpu_pool);
 	THREADPOOL_INIT();
 	ASSERT_SLEEPABLE();
 	KASSERT(threadpool_pri_is_valid(pri));
 	mutex_enter(&threadpools_lock);
 	KASSERT(tpu == threadpool_lookup_unbound(pri));
 	KASSERT(0 < tpu->tpu_refcnt);
 	if (--tpu->tpu_refcnt == 0) {
 		TP_LOG(("%s: Last reference for pri=%d, destroying pool.\n",
-			__func__, (int)pri));
+		    __func__, (int)pri));
 		threadpool_remove_unbound(tpu);
 	} else {
 		tpu = NULL;
+	}
 	mutex_exit(&threadpools_lock);
 	if (tpu) {
 		threadpool_destroy(&tpu->tpu_pool);
 		kmem_free(tpu, sizeof(*tpu));
+	}
+}
 /* Per-CPU thread pools */
 int
 threadpool_percpu_get(struct threadpool_percpu **pool_percpup, pri_t pri)
+{
 	struct threadpool_percpu *pool_percpu, *tmp = NULL;
 	int error;
 	THREADPOOL_INIT();
 	ASSERT_SLEEPABLE();
 	if (! threadpool_pri_is_valid(pri))
 		return EINVAL;
 	mutex_enter(&threadpools_lock);
 	pool_percpu = threadpool_lookup_percpu(pri);
 	if (pool_percpu == NULL) {
 		mutex_exit(&threadpools_lock);
 		TP_LOG(("%s: No pool for pri=%d, creating one.\n",
-			__func__, (int)pri));
+		    __func__, (int)pri));
 		error = threadpool_percpu_create(&tmp, pri);
 		if (error)
 			return error;
 		KASSERT(tmp != NULL);
 		mutex_enter(&threadpools_lock);
 		pool_percpu = threadpool_lookup_percpu(pri);
 		if (pool_percpu == NULL) {
 			TP_LOG(("%s: Won the creation race for pri=%d.\n",
-				__func__, (int)pri));
+			    __func__, (int)pri));
 			pool_percpu = tmp;
 			tmp = NULL;
 			threadpool_insert_percpu(pool_percpu);
+		}
+	}
 	KASSERT(pool_percpu != NULL);
 	pool_percpu->tpp_refcnt++;
 	KASSERT(pool_percpu->tpp_refcnt != 0);
 	mutex_exit(&threadpools_lock);
 	if (tmp != NULL)
 		threadpool_percpu_destroy(tmp);
 	KASSERT(pool_percpu != NULL);
 	*pool_percpup = pool_percpu;
 	return 0;
+}
 void
 threadpool_percpu_put(struct threadpool_percpu *pool_percpu, pri_t pri)
+{
 	THREADPOOL_INIT();
 	ASSERT_SLEEPABLE();
 	KASSERT(threadpool_pri_is_valid(pri));
 	mutex_enter(&threadpools_lock);
 	KASSERT(pool_percpu == threadpool_lookup_percpu(pri));
 	KASSERT(0 < pool_percpu->tpp_refcnt);
 	if (--pool_percpu->tpp_refcnt == 0) {
 		TP_LOG(("%s: Last reference for pri=%d, destroying pool.\n",
-			__func__, (int)pri));
+		    __func__, (int)pri));
 		threadpool_remove_percpu(pool_percpu);
 	} else {
 		pool_percpu = NULL;
+	}
 	mutex_exit(&threadpools_lock);
 	if (pool_percpu)
 		threadpool_percpu_destroy(pool_percpu);
+}
 struct threadpool *
 threadpool_percpu_ref(struct threadpool_percpu *pool_percpu)
+{
 	struct threadpool **poolp, *pool;
 	poolp = percpu_getref(pool_percpu->tpp_percpu);
 	pool = *poolp;
 	percpu_putref(pool_percpu->tpp_percpu);
 	return pool;
+}
 struct threadpool *
 threadpool_percpu_ref_remote(struct threadpool_percpu *pool_percpu,
     struct cpu_info *ci)
+{
 	struct threadpool **poolp, *pool;
 	percpu_traverse_enter();
 	poolp = percpu_getptr_remote(pool_percpu->tpp_percpu, ci);
 	pool = *poolp;
 	percpu_traverse_exit();
 	return pool;
+}
 static int
 threadpool_percpu_create(struct threadpool_percpu **pool_percpup, pri_t pri)
+{
 	struct threadpool_percpu *pool_percpu;
 	struct cpu_info *ci;
 	CPU_INFO_ITERATOR cii;
 	unsigned int i, j;
 	int error;
 	pool_percpu = kmem_zalloc(sizeof(*pool_percpu), KM_SLEEP);
 	if (pool_percpu == NULL) {
 		error = ENOMEM;
 		goto fail0;
+	}
 	pool_percpu->tpp_pri = pri;
 	pool_percpu->tpp_percpu = percpu_alloc(sizeof(struct threadpool *));
 	if (pool_percpu->tpp_percpu == NULL) {
 		error = ENOMEM;
 		goto fail1;
+	}
 	for (i = 0, CPU_INFO_FOREACH(cii, ci), i++) {
 		struct threadpool *pool;
 		pool = kmem_zalloc(sizeof(*pool), KM_SLEEP);
 		error = threadpool_create(pool, ci, pri);
 		if (error) {
 			kmem_free(pool, sizeof(*pool));
 			goto fail2;
+		}
 		percpu_traverse_enter();
 		struct threadpool **const poolp =
 		    percpu_getptr_remote(pool_percpu->tpp_percpu, ci);
 		*poolp = pool;
 		percpu_traverse_exit();
+	}
 	/* Success!  */
 	*pool_percpup = (struct threadpool_percpu *)pool_percpu;
 	return 0;
 fail2:	for (j = 0, CPU_INFO_FOREACH(cii, ci), j++) {
 		if (i <= j)
 			break;
 		percpu_traverse_enter();
 		struct threadpool **const poolp =
 		    percpu_getptr_remote(pool_percpu->tpp_percpu, ci);
 		struct threadpool *const pool = *poolp;
 		percpu_traverse_exit();
 		threadpool_destroy(pool);
 		kmem_free(pool, sizeof(*pool));
+	}
 	percpu_free(pool_percpu->tpp_percpu, sizeof(struct taskthread_pool *));
 fail1:	kmem_free(pool_percpu, sizeof(*pool_percpu));
 fail0:	return error;
+}
 static void
 threadpool_percpu_destroy(struct threadpool_percpu *pool_percpu)
+{
 	struct cpu_info *ci;
 	CPU_INFO_ITERATOR cii;
 	for (CPU_INFO_FOREACH(cii, ci)) {
 		percpu_traverse_enter();
 		struct threadpool **const poolp =
 		    percpu_getptr_remote(pool_percpu->tpp_percpu, ci);
 		struct threadpool *const pool = *poolp;
 		percpu_traverse_exit();
 		threadpool_destroy(pool);
 		kmem_free(pool, sizeof(*pool));
+	}
 	percpu_free(pool_percpu->tpp_percpu, sizeof(struct threadpool *));
 	kmem_free(pool_percpu, sizeof(*pool_percpu));
+}
 /* Thread pool jobs */
 void __printflike(4,5)
 threadpool_job_init(struct threadpool_job *job, threadpool_job_fn_t fn,
     kmutex_t *lock, const char *fmt, ...)
+{
 	va_list ap;
 	va_start(ap, fmt);
 	(void)vsnprintf(job->job_name, sizeof(job->job_name), fmt, ap);
 	va_end(ap);
 	job->job_lock = lock;
 	job->job_thread = NULL;
 	job->job_refcnt = 0;
 	cv_init(&job->job_cv, job->job_name);
 	job->job_fn = fn;
+}
 static void
 threadpool_job_dead(struct threadpool_job *job)
+{
 	panic("threadpool job %p ran after destruction", job);
+}
 void
 threadpool_job_destroy(struct threadpool_job *job)
+{
 	ASSERT_SLEEPABLE();
 	KASSERTMSG((job->job_thread == NULL), "job %p still running", job);
 	mutex_enter(job->job_lock);
 	while (0 < job->job_refcnt)
 		cv_wait(&job->job_cv, job->job_lock);
 	mutex_exit(job->job_lock);
 	job->job_lock = NULL;
 	KASSERT(job->job_thread == NULL);
 	KASSERT(job->job_refcnt == 0);
 	KASSERT(!cv_has_waiters(&job->job_cv));
 	cv_destroy(&job->job_cv);
 	job->job_fn = threadpool_job_dead;
 	(void)strlcpy(job->job_name, "deadjob", sizeof(job->job_name));
+}
 static int
 threadpool_job_hold(struct threadpool_job *job)
+{
 	unsigned int refcnt;
 	do {
 		refcnt = job->job_refcnt;
 		if (refcnt == UINT_MAX)
 			return EBUSY;
 	} while (atomic_cas_uint(&job->job_refcnt, refcnt, (refcnt + 1))
 	    != refcnt);
 	return 0;
+}
 static void
 threadpool_job_rele(struct threadpool_job *job)
+{
 	unsigned int refcnt;
 	do {
 		refcnt = job->job_refcnt;
 		KASSERT(0 < refcnt);
 		if (refcnt == 1) {
 			mutex_enter(job->job_lock);
 			refcnt = atomic_dec_uint_nv(&job->job_refcnt);
 			KASSERT(refcnt != UINT_MAX);
 			if (refcnt == 0)
 				cv_broadcast(&job->job_cv);
 			mutex_exit(job->job_lock);
 			return;
+		}
 	} while (atomic_cas_uint(&job->job_refcnt, refcnt, (refcnt - 1))
 	    != refcnt);
+}
 void
 threadpool_job_done(struct threadpool_job *job)
+{
 	KASSERT(mutex_owned(job->job_lock));
 	KASSERT(job->job_thread != NULL);
 	KASSERT(job->job_thread->tpt_lwp == curlwp);
 	cv_broadcast(&job->job_cv);
 	job->job_thread = NULL;
+}
 void
 threadpool_schedule_job(struct threadpool *pool, struct threadpool_job *job)
+{
 	KASSERT(mutex_owned(job->job_lock));
 	/*
 	 * If the job's already running, let it keep running.  The job
 	 * is guaranteed by the interlock not to end early -- if it had
 	 * ended early, threadpool_job_done would have set job_thread
 	 * to NULL under the interlock.
 	 */
 	if (__predict_true(job->job_thread != NULL)) {
 		TP_LOG(("%s: job '%s' already runnining.\n",
-			__func__, job->job_name));
+		    __func__, job->job_name));
 		return;
+	}
 	/* Otherwise, try to assign a thread to the job.  */
 	mutex_spin_enter(&pool->tp_lock);
 	if (__predict_false(TAILQ_EMPTY(&pool->tp_idle_threads))) {
 		/* Nobody's idle.  Give it to the overseer.  */
 		TP_LOG(("%s: giving job '%s' to overseer.\n",
-			__func__, job->job_name));
+		    __func__, job->job_name));
 		job->job_thread = &pool->tp_overseer;
 		TAILQ_INSERT_TAIL(&pool->tp_jobs, job, job_entry);
 	} else {
 		/* Assign it to the first idle thread.  */
 		job->job_thread = TAILQ_FIRST(&pool->tp_idle_threads);
 		TP_LOG(("%s: giving job '%s' to idle thread %p.\n",
-			__func__, job->job_name, job->job_thread));
+		    __func__, job->job_name, job->job_thread));
 		TAILQ_REMOVE(&pool->tp_idle_threads, job->job_thread,
 		    tpt_entry);
 		threadpool_job_hold(job);
 		job->job_thread->tpt_job = job;
+	}
 	/* Notify whomever we gave it to, overseer or idle thread.  */
 	KASSERT(job->job_thread != NULL);
 	cv_broadcast(&job->job_thread->tpt_cv);
 	mutex_spin_exit(&pool->tp_lock);
+}
 bool
 threadpool_cancel_job_async(struct threadpool *pool, struct threadpool_job *job)
+{
 	KASSERT(mutex_owned(job->job_lock));
 	/*
 	 * XXXJRT This fails (albeit safely) when all of the following
 	 * are true:
+	 *
 	 *	=> "pool" is something other than what the job was
 	 *	   scheduled on.  This can legitimately occur if,
 	 *	   for example, a job is percpu-scheduled on CPU0
 	 *	   and then CPU1 attempts to cancel it without taking
 	 *	   a remote pool reference.  (this might happen by
 	 *	   "luck of the draw").
+	 *
 	 *	=> "job" is not yet running, but is assigned to the
 	 *	   overseer.
+	 *
 	 * When this happens, this code makes the determination that
 	 * the job is already running.  The failure mode is that the
 	 * caller is told the job is running, and thus has to wait.
 	 * The overseer will eventually get to it and the job will
 	 * proceed as if it had been already running.
 	 */
 	if (job->job_thread == NULL) {
 		/* Nothing to do.  Guaranteed not running.  */
 		return true;
 	} else if (job->job_thread == &pool->tp_overseer) {
 		/* Take it off the list to guarantee it won't run.  */
 		job->job_thread = NULL;
 		mutex_spin_enter(&pool->tp_lock);
 		TAILQ_REMOVE(&pool->tp_jobs, job, job_entry);
 		mutex_spin_exit(&pool->tp_lock);
 		return true;
 	} else {
 		/* Too late -- already running.  */
 		return false;
+	}
+}
 void
 threadpool_cancel_job(struct threadpool *pool, struct threadpool_job *job)
+{
 	ASSERT_SLEEPABLE();
 	KASSERT(mutex_owned(job->job_lock));
 	if (threadpool_cancel_job_async(pool, job))
 		return;
 	/* Already running.  Wait for it to complete.  */
 	while (job->job_thread != NULL)
 		cv_wait(&job->job_cv, job->job_lock);
+}
 /* Thread pool overseer thread */
 static void __dead
 threadpool_overseer_thread(void *arg)
+{
 	struct threadpool_thread *const overseer = arg;
 	struct threadpool *const pool = overseer->tpt_pool;
 	struct lwp *lwp = NULL;
 	int ktflags;
 	int error;
 	KASSERT((pool->tp_cpu == NULL) || (pool->tp_cpu == curcpu()));
 	/* Wait until we're initialized.  */
 	mutex_spin_enter(&pool->tp_lock);
 	while (overseer->tpt_lwp == NULL)
 		cv_wait(&overseer->tpt_cv, &pool->tp_lock);
 	TP_LOG(("%s: starting.\n", __func__));
 	for (;;) {
 		/* Wait until there's a job.  */
 		while (TAILQ_EMPTY(&pool->tp_jobs)) {
 			if (ISSET(pool->tp_flags, THREADPOOL_DYING)) {
 				TP_LOG(("%s: THREADPOOL_DYING\n",
-					__func__));
+				    __func__));
 				break;
+			}
 			cv_wait(&overseer->tpt_cv, &pool->tp_lock);
+		}
 		if (__predict_false(TAILQ_EMPTY(&pool->tp_jobs)))
 			break;
 		/* If there are no threads, we'll have to try to start one.  */
 		if (TAILQ_EMPTY(&pool->tp_idle_threads)) {
 			TP_LOG(("%s: Got a job, need to create a thread.\n",
-				__func__));
+			    __func__));
 			threadpool_hold(pool);
 			mutex_spin_exit(&pool->tp_lock);
 			struct threadpool_thread *const thread =
 			    pool_cache_get(threadpool_thread_pc, PR_WAITOK);
 			thread->tpt_lwp = NULL;
 			thread->tpt_pool = pool;
 			thread->tpt_job = NULL;
 			cv_init(&thread->tpt_cv, "poolthrd");
 			ktflags = 0;
 			ktflags |= KTHREAD_MPSAFE;
 			if (pool->tp_pri < PRI_KERNEL)
 				ktflags |= KTHREAD_TS;
 			error = kthread_create(pool->tp_pri, ktflags,
 			    pool->tp_cpu, &threadpool_thread, thread, &lwp,
 			    "poolthread/%d@%d",
 			    (pool->tp_cpu ? cpu_index(pool->tp_cpu) : -1),
 			    (int)pool->tp_pri);
 			mutex_spin_enter(&pool->tp_lock);
 			if (error) {
 				pool_cache_put(threadpool_thread_pc, thread);
 				threadpool_rele(pool);
 				/* XXX What to do to wait for memory?  */
 				(void)kpause("thrdplcr", false, hz,
 				    &pool->tp_lock);
 				continue;
+			}
 			/*
 			 * New kthread now owns the reference to the pool
 			 * taken above.
 			 */
 			KASSERT(lwp != NULL);
 			TAILQ_INSERT_TAIL(&pool->tp_idle_threads, thread,
 			    tpt_entry);
 			thread->tpt_lwp = lwp;
 			lwp = NULL;
 			cv_broadcast(&thread->tpt_cv);
 			continue;
+		}
 		/* There are idle threads, so try giving one a job.  */
 		bool rele_job = true;
 		struct threadpool_job *const job = TAILQ_FIRST(&pool->tp_jobs);
 		TAILQ_REMOVE(&pool->tp_jobs, job, job_entry);
 		error = threadpool_job_hold(job);
 		if (error) {
 			TAILQ_INSERT_HEAD(&pool->tp_jobs, job, job_entry);
 			(void)kpause("pooljob", false, hz, &pool->tp_lock);
 			continue;
+		}
 		mutex_spin_exit(&pool->tp_lock);
 		mutex_enter(job->job_lock);
 		/* If the job was cancelled, we'll no longer be its thread.  */
 		if (__predict_true(job->job_thread == overseer)) {
 			mutex_spin_enter(&pool->tp_lock);
 			if (__predict_false(
 				    TAILQ_EMPTY(&pool->tp_idle_threads))) {
 				/*
 				 * Someone else snagged the thread
 				 * first.  We'll have to try again.
 				 */
 				TP_LOG(("%s: '%s' lost race to use idle thread.\n",
-					__func__, job->job_name));
+				    __func__, job->job_name));
 				TAILQ_INSERT_HEAD(&pool->tp_jobs, job,
 				    job_entry);
 			} else {
 				/*
 				 * Assign the job to the thread and
 				 * wake the thread so it starts work.
 				 */
 				struct threadpool_thread *const thread =
 				    TAILQ_FIRST(&pool->tp_idle_threads);
 				TP_LOG(("%s: '%s' gets thread %p\n",
-					__func__, job->job_name, thread));
+				    __func__, job->job_name, thread));
 				KASSERT(thread->tpt_job == NULL);
 				TAILQ_REMOVE(&pool->tp_idle_threads, thread,
 				    tpt_entry);
 				thread->tpt_job = job;
 				job->job_thread = thread;
 				cv_broadcast(&thread->tpt_cv);
 				/* Gave the thread our job reference.  */
 				rele_job = false;
+			}
 			mutex_spin_exit(&pool->tp_lock);
+		}
 		mutex_exit(job->job_lock);
 		if (__predict_false(rele_job))
 			threadpool_job_rele(job);
 		mutex_spin_enter(&pool->tp_lock);
+	}
 	threadpool_rele(pool);
 	mutex_spin_exit(&pool->tp_lock);
 	TP_LOG(("%s: exiting.\n", __func__));
 	kthread_exit(0);
+}
 /* Thread pool thread */
 static void __dead
 threadpool_thread(void *arg)
+{
 	struct threadpool_thread *const thread = arg;
 	struct threadpool *const pool = thread->tpt_pool;
 	KASSERT((pool->tp_cpu == NULL) || (pool->tp_cpu == curcpu()));
 	/* Wait until we're initialized and on the queue.  */
 	mutex_spin_enter(&pool->tp_lock);
 	while (thread->tpt_lwp == NULL)
 		cv_wait(&thread->tpt_cv, &pool->tp_lock);
 	TP_LOG(("%s: starting.\n", __func__));
 	KASSERT(thread->tpt_lwp == curlwp);
 	for (;;) {
 		/* Wait until we are assigned a job.  */
 		while (thread->tpt_job == NULL) {
 			if (ISSET(pool->tp_flags, THREADPOOL_DYING)) {
 				TP_LOG(("%s: THREADPOOL_DYING\n",
-					__func__));
+				    __func__));
 				break;
+			}
 			if (cv_timedwait(&thread->tpt_cv, &pool->tp_lock,
-					 THREADPOOL_IDLE_TICKS))
+				THREADPOOL_IDLE_TICKS))
 				break;
+		}
 		if (__predict_false(thread->tpt_job == NULL)) {
 			TAILQ_REMOVE(&pool->tp_idle_threads, thread,
 			    tpt_entry);
 			break;
+		}
 		struct threadpool_job *const job = thread->tpt_job;
 		KASSERT(job != NULL);
 		mutex_spin_exit(&pool->tp_lock);
 		TP_LOG(("%s: running job '%s' on thread %p.\n",
-			__func__, job->job_name, thread));
+		    __func__, job->job_name, thread));
 		/* Set our lwp name to reflect what job we're doing.  */
 		lwp_lock(curlwp);
 		char *const lwp_name = curlwp->l_name;
 		curlwp->l_name = job->job_name;
 		lwp_unlock(curlwp);
 		/* Run the job.  */
 		(*job->job_fn)(job);
 		/* Restore our lwp name.  */
 		lwp_lock(curlwp);
 		curlwp->l_name = lwp_name;
 		lwp_unlock(curlwp);
 		/* Job is done and its name is unreferenced.  Release it.  */
 		threadpool_job_rele(job);
 		mutex_spin_enter(&pool->tp_lock);
 		KASSERT(thread->tpt_job == job);
 		thread->tpt_job = NULL;
 		TAILQ_INSERT_TAIL(&pool->tp_idle_threads, thread, tpt_entry);
+	}
 	threadpool_rele(pool);
 	mutex_spin_exit(&pool->tp_lock);
 	TP_LOG(("%s: thread %p exiting.\n", __func__, thread));
 	KASSERT(!cv_has_waiters(&thread->tpt_cv));
 	cv_destroy(&thread->tpt_cv);
 	pool_cache_put(threadpool_thread_pc, thread);
 	kthread_exit(0);
+}