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-rw-r--r--module/spl/spl-taskq.c29
1 files changed, 16 insertions, 13 deletions
diff --git a/module/spl/spl-taskq.c b/module/spl/spl-taskq.c
index 0b3b3a131..67a834572 100644
--- a/module/spl/spl-taskq.c
+++ b/module/spl/spl-taskq.c
@@ -156,19 +156,22 @@ task_done(taskq_t *tq, taskq_ent_t *t)
* monotonically increasing taskqid and added to the tail of the pending
* list. As worker threads become available the tasks are removed from
* the head of the pending or priority list, giving preference to the
- * priority list. The tasks are then added to the work list, preserving
- * the ordering by taskqid. Finally, as tasks complete they are removed
- * from the work list. This means that the pending and work lists are
- * always kept sorted by taskqid. Thus the lowest outstanding
- * incomplete taskqid can be determined simply by checking the min
- * taskqid for each head item on the pending, priority, and work list.
- * This value is stored in tq->tq_lowest_id and only updated to the new
- * lowest id when the previous lowest id completes. All taskqids lower
- * than tq->tq_lowest_id must have completed. It is also possible
- * larger taskqid's have completed because they may be processed in
- * parallel by several worker threads. However, this is not a problem
- * because the behavior of taskq_wait_id() is to block until all
- * previously submitted taskqid's have completed.
+ * priority list. The tasks are then removed from their respective
+ * list, and the taskq_thread servicing the task is added to the active
+ * list, preserving the order using the serviced task's taskqid.
+ * Finally, as tasks complete the taskq_thread servicing the task is
+ * removed from the active list. This means that the pending task and
+ * active taskq_thread lists are always kept sorted by taskqid. Thus the
+ * lowest outstanding incomplete taskqid can be determined simply by
+ * checking the min taskqid for each head item on the pending, priority,
+ * and active taskq_thread list. This value is stored in
+ * tq->tq_lowest_id and only updated to the new lowest id when the
+ * previous lowest id completes. All taskqids lower than
+ * tq->tq_lowest_id must have completed. It is also possible larger
+ * taskqid's have completed because they may be processed in parallel by
+ * several worker threads. However, this is not a problem because the
+ * behavior of taskq_wait_id() is to block until all previously
+ * submitted taskqid's have completed.
*
* XXX: Taskqid_t wrapping is not handled. However, taskqid_t's are
* 64-bit values so even if a taskq is processing 2^24 (16,777,216)