[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit
Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/os/linux/linux-3.4.x/fs/btrfs/async-thread.h b/ap/os/linux/linux-3.4.x/fs/btrfs/async-thread.h
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+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef __BTRFS_ASYNC_THREAD_
+#define __BTRFS_ASYNC_THREAD_
+
+struct btrfs_worker_thread;
+
+/*
+ * This is similar to a workqueue, but it is meant to spread the operations
+ * across all available cpus instead of just the CPU that was used to
+ * queue the work. There is also some batching introduced to try and
+ * cut down on context switches.
+ *
+ * By default threads are added on demand up to 2 * the number of cpus.
+ * Changing struct btrfs_workers->max_workers is one way to prevent
+ * demand creation of kthreads.
+ *
+ * the basic model of these worker threads is to embed a btrfs_work
+ * structure in your own data struct, and use container_of in a
+ * work function to get back to your data struct.
+ */
+struct btrfs_work {
+ /*
+ * func should be set to the function you want called
+ * your work struct is passed as the only arg
+ *
+ * ordered_func must be set for work sent to an ordered work queue,
+ * and it is called to complete a given work item in the same
+ * order they were sent to the queue.
+ */
+ void (*func)(struct btrfs_work *work);
+ void (*ordered_func)(struct btrfs_work *work);
+ void (*ordered_free)(struct btrfs_work *work);
+
+ /*
+ * flags should be set to zero. It is used to make sure the
+ * struct is only inserted once into the list.
+ */
+ unsigned long flags;
+
+ /* don't touch these */
+ struct btrfs_worker_thread *worker;
+ struct list_head list;
+ struct list_head order_list;
+};
+
+struct btrfs_workers {
+ /* current number of running workers */
+ int num_workers;
+
+ int num_workers_starting;
+
+ /* max number of workers allowed. changed by btrfs_start_workers */
+ int max_workers;
+
+ /* once a worker has this many requests or fewer, it is idle */
+ int idle_thresh;
+
+ /* force completions in the order they were queued */
+ int ordered;
+
+ /* more workers required, but in an interrupt handler */
+ int atomic_start_pending;
+
+ /*
+ * are we allowed to sleep while starting workers or are we required
+ * to start them at a later time? If we can't sleep, this indicates
+ * which queue we need to use to schedule thread creation.
+ */
+ struct btrfs_workers *atomic_worker_start;
+
+ /* list with all the work threads. The workers on the idle thread
+ * may be actively servicing jobs, but they haven't yet hit the
+ * idle thresh limit above.
+ */
+ struct list_head worker_list;
+ struct list_head idle_list;
+
+ /*
+ * when operating in ordered mode, this maintains the list
+ * of work items waiting for completion
+ */
+ struct list_head order_list;
+ struct list_head prio_order_list;
+
+ /* lock for finding the next worker thread to queue on */
+ spinlock_t lock;
+
+ /* lock for the ordered lists */
+ spinlock_t order_lock;
+
+ /* extra name for this worker, used for current->name */
+ char *name;
+};
+
+void btrfs_queue_worker(struct btrfs_workers *workers, struct btrfs_work *work);
+int btrfs_start_workers(struct btrfs_workers *workers);
+void btrfs_stop_workers(struct btrfs_workers *workers);
+void btrfs_init_workers(struct btrfs_workers *workers, char *name, int max,
+ struct btrfs_workers *async_starter);
+void btrfs_requeue_work(struct btrfs_work *work);
+void btrfs_set_work_high_prio(struct btrfs_work *work);
+#endif