Function taskq_create

freebsd/contrib/openzfs/module/os/linux/spl/spl-taskq.c:1034–1140

}

taskq_t *
taskq_create(const char *name, int threads_arg, pri_t pri,
    int minalloc, int maxalloc, uint_t flags)
{
	taskq_t *tq;
	taskq_thread_t *tqt;
	int count = 0, rc = 0, i;
	unsigned long irqflags;
	int nthreads = threads_arg;

	ASSERT(name != NULL);
	ASSERT(minalloc >= 0);
	ASSERT(maxalloc <= INT_MAX);
	ASSERT(!(flags & (TASKQ_CPR_SAFE))); /* Unsupported */

	/* Scale the number of threads using nthreads as a percentage */
	if (flags & TASKQ_THREADS_CPU_PCT) {
		ASSERT(nthreads <= 100);
		ASSERT(nthreads >= 0);
		nthreads = MIN(threads_arg, 100);
		nthreads = MAX(nthreads, 0);
		nthreads = MAX((num_online_cpus() * nthreads) /100, 1);
	}

	tq = kmem_alloc(sizeof (*tq), KM_PUSHPAGE);
	if (tq == NULL)
		return (NULL);

	tq->tq_hp_support = B_FALSE;
#ifdef HAVE_CPU_HOTPLUG
	if (flags & TASKQ_THREADS_CPU_PCT) {
		tq->tq_hp_support = B_TRUE;
		if (cpuhp_state_add_instance_nocalls(spl_taskq_cpuhp_state,
		    &tq->tq_hp_cb_node) != 0) {
			kmem_free(tq, sizeof (*tq));
			return (NULL);
		}
	}
#endif

	spin_lock_init(&tq->tq_lock);
	INIT_LIST_HEAD(&tq->tq_thread_list);
	INIT_LIST_HEAD(&tq->tq_active_list);
	tq->tq_name = kmem_strdup(name);
	tq->tq_nactive = 0;
	tq->tq_nthreads = 0;
	tq->tq_nspawn = 0;
	tq->tq_maxthreads = nthreads;
	tq->tq_cpu_pct = threads_arg;
	tq->tq_pri = pri;
	tq->tq_minalloc = minalloc;
	tq->tq_maxalloc = maxalloc;
	tq->tq_nalloc = 0;
	tq->tq_flags = (flags | TASKQ_ACTIVE);
	tq->tq_next_id = TASKQID_INITIAL;
	tq->tq_lowest_id = TASKQID_INITIAL;
	INIT_LIST_HEAD(&tq->tq_free_list);
	INIT_LIST_HEAD(&tq->tq_pend_list);