waterDataFluctuationCorrelation preliminaryDataProcessing.c 张婷 commit at 2021-04-25

waterDataFluctuationCorrelation/monitoringDataProcessing/preliminaryDataProcessing.c

@@ -2965,3 +2965,112 @@ struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug, void *data,
 	/* Not currently on the callback list */
 	BUG_ON(size < sizeof(*cb));
 	cb = kzalloc(size, GFP_ATOMIC);
+	if (cb) {
+		cb->data = data;
+		cb->callback = unplug;
+		list_add(&cb->list, &plug->cb_list);
+	}
+	return cb;
+}
+EXPORT_SYMBOL(blk_check_plugged);
+
+void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
+{
+	struct request_queue *q;
+	unsigned long flags;
+	struct request *rq;
+	LIST_HEAD(list);
+	unsigned int depth;
+
+	BUG_ON(plug->magic != PLUG_MAGIC);
+
+	flush_plug_callbacks(plug, from_schedule);
+	if (list_empty(&plug->list))
+		return;
+
+	list_splice_init(&plug->list, &list);
+
+	if (plug->should_sort) {
+		list_sort(NULL, &list, plug_rq_cmp);
+		plug->should_sort = 0;
+	}
+
+	q = NULL;
+	depth = 0;
+
+	/*
+	 * Save and disable interrupts here, to avoid doing it for every
+	 * queue lock we have to take.
+	 */
+	local_irq_save(flags);
+	while (!list_empty(&list)) {
+		rq = list_entry_rq(list.next);
+		list_del_init(&rq->queuelist);
+		BUG_ON(!rq->q);
+		if (rq->q != q) {
+			/*
+			 * This drops the queue lock
+			 */
+			if (q)
+				queue_unplugged(q, depth, from_schedule);
+			q = rq->q;
+			depth = 0;
+			spin_lock(q->queue_lock);
+		}
+
+		/*
+		 * Short-circuit if @q is dead
+		 */
+		if (unlikely(blk_queue_dying(q))) {
+			__blk_end_request_all(rq, -ENODEV);
+			continue;
+		}
+
+		/*
+		 * rq is already accounted, so use raw insert
+		 */
+		if (rq->cmd_flags & (REQ_FLUSH | REQ_FUA))
+			__elv_add_request(q, rq, ELEVATOR_INSERT_FLUSH);
+		else
+			__elv_add_request(q, rq, ELEVATOR_INSERT_SORT_MERGE);
+
+		depth++;
+	}
+
+	/*
+	 * This drops the queue lock
+	 */
+	if (q)
+		queue_unplugged(q, depth, from_schedule);
+
+	local_irq_restore(flags);
+}
+
+void blk_finish_plug(struct blk_plug *plug)
+{
+	blk_flush_plug_list(plug, false);
+
+	if (plug == current->plug)
+		current->plug = NULL;
+}
+EXPORT_SYMBOL(blk_finish_plug);
+
+int __init blk_dev_init(void)
+{
+	BUILD_BUG_ON(__REQ_NR_BITS > 8 *
+			sizeof(((struct request *)0)->cmd_flags));
+
+	/* used for unplugging and affects IO latency/throughput - HIGHPRI */
+	kblockd_workqueue = alloc_workqueue("kblockd",
+					    WQ_MEM_RECLAIM | WQ_HIGHPRI, 0);
+	if (!kblockd_workqueue)
+		panic("Failed to create kblockd\n");
+
+	request_cachep = kmem_cache_create("blkdev_requests",
+			sizeof(struct request), 0, SLAB_PANIC, NULL);
+
+	blk_requestq_cachep = kmem_cache_create("blkdev_queue",
+			sizeof(struct request_queue), 0, SLAB_PANIC, NULL);
+
+	return 0;
+}