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Diffstat (limited to 'sys/contrib/openzfs/module/os/linux/spl/spl-taskq.c')
-rw-r--r--sys/contrib/openzfs/module/os/linux/spl/spl-taskq.c85
1 files changed, 29 insertions, 56 deletions
diff --git a/sys/contrib/openzfs/module/os/linux/spl/spl-taskq.c b/sys/contrib/openzfs/module/os/linux/spl/spl-taskq.c
index d18f935b167c..0e44aa1fcd38 100644
--- a/sys/contrib/openzfs/module/os/linux/spl/spl-taskq.c
+++ b/sys/contrib/openzfs/module/os/linux/spl/spl-taskq.c
@@ -36,12 +36,12 @@ static int spl_taskq_thread_bind = 0;
module_param(spl_taskq_thread_bind, int, 0644);
MODULE_PARM_DESC(spl_taskq_thread_bind, "Bind taskq thread to CPU by default");
-static uint_t spl_taskq_thread_timeout_ms = 10000;
+static uint_t spl_taskq_thread_timeout_ms = 5000;
/* BEGIN CSTYLED */
module_param(spl_taskq_thread_timeout_ms, uint, 0644);
/* END CSTYLED */
MODULE_PARM_DESC(spl_taskq_thread_timeout_ms,
- "Time to require a dynamic thread be idle before it gets cleaned up");
+ "Minimum idle threads exit interval for dynamic taskqs");
static int spl_taskq_thread_dynamic = 1;
module_param(spl_taskq_thread_dynamic, int, 0444);
@@ -594,8 +594,7 @@ taskq_dispatch(taskq_t *tq, task_func_t func, void *arg, uint_t flags)
ASSERT(tq->tq_nactive <= tq->tq_nthreads);
if ((flags & TQ_NOQUEUE) && (tq->tq_nactive == tq->tq_nthreads)) {
/* Dynamic taskq may be able to spawn another thread */
- if (!(tq->tq_flags & TASKQ_DYNAMIC) ||
- taskq_thread_spawn(tq) == 0)
+ if (taskq_thread_spawn(tq) == 0)
goto out;
}
@@ -629,11 +628,11 @@ taskq_dispatch(taskq_t *tq, task_func_t func, void *arg, uint_t flags)
spin_unlock(&t->tqent_lock);
wake_up(&tq->tq_work_waitq);
-out:
+
/* Spawn additional taskq threads if required. */
if (!(flags & TQ_NOQUEUE) && tq->tq_nactive == tq->tq_nthreads)
(void) taskq_thread_spawn(tq);
-
+out:
spin_unlock_irqrestore(&tq->tq_lock, irqflags);
return (rc);
}
@@ -676,10 +675,11 @@ taskq_dispatch_delay(taskq_t *tq, task_func_t func, void *arg,
ASSERT(!(t->tqent_flags & TQENT_FLAG_PREALLOC));
spin_unlock(&t->tqent_lock);
-out:
+
/* Spawn additional taskq threads if required. */
if (tq->tq_nactive == tq->tq_nthreads)
(void) taskq_thread_spawn(tq);
+out:
spin_unlock_irqrestore(&tq->tq_lock, irqflags);
return (rc);
}
@@ -704,9 +704,8 @@ taskq_dispatch_ent(taskq_t *tq, task_func_t func, void *arg, uint_t flags,
if ((flags & TQ_NOQUEUE) && (tq->tq_nactive == tq->tq_nthreads)) {
/* Dynamic taskq may be able to spawn another thread */
- if (!(tq->tq_flags & TASKQ_DYNAMIC) ||
- taskq_thread_spawn(tq) == 0)
- goto out2;
+ if (taskq_thread_spawn(tq) == 0)
+ goto out;
flags |= TQ_FRONT;
}
@@ -742,11 +741,11 @@ taskq_dispatch_ent(taskq_t *tq, task_func_t func, void *arg, uint_t flags,
spin_unlock(&t->tqent_lock);
wake_up(&tq->tq_work_waitq);
-out:
+
/* Spawn additional taskq threads if required. */
if (tq->tq_nactive == tq->tq_nthreads)
(void) taskq_thread_spawn(tq);
-out2:
+out:
spin_unlock_irqrestore(&tq->tq_lock, irqflags);
}
EXPORT_SYMBOL(taskq_dispatch_ent);
@@ -825,6 +824,7 @@ taskq_thread_spawn(taskq_t *tq)
if (!(tq->tq_flags & TASKQ_DYNAMIC))
return (0);
+ tq->lastspawnstop = jiffies;
if ((tq->tq_nthreads + tq->tq_nspawn < tq->tq_maxthreads) &&
(tq->tq_flags & TASKQ_ACTIVE)) {
spawning = (++tq->tq_nspawn);
@@ -836,9 +836,9 @@ taskq_thread_spawn(taskq_t *tq)
}
/*
- * Threads in a dynamic taskq should only exit once it has been completely
- * drained and no other threads are actively servicing tasks. This prevents
- * threads from being created and destroyed more than is required.
+ * Threads in a dynamic taskq may exit once there is no more work to do.
+ * To prevent threads from being created and destroyed too often limit
+ * the exit rate to one per spl_taskq_thread_timeout_ms.
*
* The first thread is the thread list is treated as the primary thread.
* There is nothing special about the primary thread but in order to avoid
@@ -847,44 +847,22 @@ taskq_thread_spawn(taskq_t *tq)
static int
taskq_thread_should_stop(taskq_t *tq, taskq_thread_t *tqt)
{
- if (!(tq->tq_flags & TASKQ_DYNAMIC))
+ ASSERT(!taskq_next_ent(tq));
+ if (!(tq->tq_flags & TASKQ_DYNAMIC) || !spl_taskq_thread_dynamic)
return (0);
-
+ if (!(tq->tq_flags & TASKQ_ACTIVE))
+ return (1);
if (list_first_entry(&(tq->tq_thread_list), taskq_thread_t,
tqt_thread_list) == tqt)
return (0);
-
- int no_work =
- ((tq->tq_nspawn == 0) && /* No threads are being spawned */
- (tq->tq_nactive == 0) && /* No threads are handling tasks */
- (tq->tq_nthreads > 1) && /* More than 1 thread is running */
- (!taskq_next_ent(tq)) && /* There are no pending tasks */
- (spl_taskq_thread_dynamic)); /* Dynamic taskqs are allowed */
-
- /*
- * If we would have said stop before, let's instead wait a bit, maybe
- * we'll see more work come our way soon...
- */
- if (no_work) {
- /* if it's 0, we want the old behavior. */
- /* if the taskq is being torn down, we also want to go away. */
- if (spl_taskq_thread_timeout_ms == 0 ||
- !(tq->tq_flags & TASKQ_ACTIVE))
- return (1);
- unsigned long lasttime = tq->lastshouldstop;
- if (lasttime > 0) {
- if (time_after(jiffies, lasttime +
- msecs_to_jiffies(spl_taskq_thread_timeout_ms)))
- return (1);
- else
- return (0);
- } else {
- tq->lastshouldstop = jiffies;
- }
- } else {
- tq->lastshouldstop = 0;
- }
- return (0);
+ ASSERT3U(tq->tq_nthreads, >, 1);
+ if (tq->tq_nspawn != 0)
+ return (0);
+ if (time_before(jiffies, tq->lastspawnstop +
+ msecs_to_jiffies(spl_taskq_thread_timeout_ms)))
+ return (0);
+ tq->lastspawnstop = jiffies;
+ return (1);
}
static int
@@ -935,10 +913,8 @@ taskq_thread(void *args)
if (list_empty(&tq->tq_pend_list) &&
list_empty(&tq->tq_prio_list)) {
- if (taskq_thread_should_stop(tq, tqt)) {
- wake_up_all(&tq->tq_wait_waitq);
+ if (taskq_thread_should_stop(tq, tqt))
break;
- }
add_wait_queue_exclusive(&tq->tq_work_waitq, &wait);
spin_unlock_irqrestore(&tq->tq_lock, flags);
@@ -1013,9 +989,6 @@ taskq_thread(void *args)
tqt->tqt_id = TASKQID_INVALID;
tqt->tqt_flags = 0;
wake_up_all(&tq->tq_wait_waitq);
- } else {
- if (taskq_thread_should_stop(tq, tqt))
- break;
}
set_current_state(TASK_INTERRUPTIBLE);
@@ -1122,7 +1095,7 @@ taskq_create(const char *name, int threads_arg, pri_t pri,
tq->tq_flags = (flags | TASKQ_ACTIVE);
tq->tq_next_id = TASKQID_INITIAL;
tq->tq_lowest_id = TASKQID_INITIAL;
- tq->lastshouldstop = 0;
+ tq->lastspawnstop = jiffies;
INIT_LIST_HEAD(&tq->tq_free_list);
INIT_LIST_HEAD(&tq->tq_pend_list);
INIT_LIST_HEAD(&tq->tq_prio_list);