On Tue, Aug 21, 2018 at 8:45 AM Jason Wang [off-list ref] wrote:

On 2018年08月19日 20:11, xiangxia.m.yue@gmail.com wrote:

quoted

From: Tonghao Zhang <redacted>

The bitmap of vhost_dev can help us to check if the
specified poll is scheduled. This patch will be used
for next two patches.

Signed-off-by: Tonghao Zhang <redacted>
---
  drivers/vhost/net.c   | 11 +++++++++--
  drivers/vhost/vhost.c | 17 +++++++++++++++--
  drivers/vhost/vhost.h |  7 ++++++-
  3 files changed, 30 insertions(+), 5 deletions(-)

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 1eff72d..23d7ffc 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c

@@ -1135,8 +1135,15 @@ static int vhost_net_open(struct inode *inode, struct file *f)
      }
      vhost_dev_init(dev, vqs, VHOST_NET_VQ_MAX);

-     vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, EPOLLOUT, dev);
-     vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, EPOLLIN, dev);
+     vhost_poll_init(n->poll + VHOST_NET_VQ_TX,
+                     handle_tx_net,
+                     VHOST_NET_VQ_TX,
+                     EPOLLOUT, dev);
+
+     vhost_poll_init(n->poll + VHOST_NET_VQ_RX,
+                     handle_rx_net,
+                     VHOST_NET_VQ_RX,
+                     EPOLLIN, dev);

      f->private_data = n;

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index a1c06e7..dc88a60 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c

@@ -186,7 +186,7 @@ void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn)

  /* Init poll structure */
  void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
-                  __poll_t mask, struct vhost_dev *dev)
+                  __u8 poll_id, __poll_t mask, struct vhost_dev *dev)
  {
      init_waitqueue_func_entry(&poll->wait, vhost_poll_wakeup);
      init_poll_funcptr(&poll->table, vhost_poll_func);

@@ -194,6 +194,7 @@ void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
      poll->dev = dev;
      poll->wqh = NULL;

+     poll->poll_id = poll_id;
      vhost_work_init(&poll->work, fn);
  }
  EXPORT_SYMBOL_GPL(vhost_poll_init);

@@ -276,8 +277,16 @@ bool vhost_has_work(struct vhost_dev *dev)
  }
  EXPORT_SYMBOL_GPL(vhost_has_work);

+bool vhost_has_work_pending(struct vhost_dev *dev, int poll_id)
+{
+     return !llist_empty(&dev->work_list) &&
+             test_bit(poll_id, dev->work_pending);

I think we've already had something similar. E.g can we test
VHOST_WORK_QUEUED instead?

done, thanks. I am busy two weeks ago, and now I focus on these patches.

Thanks

quoted

+}
+EXPORT_SYMBOL_GPL(vhost_has_work_pending);
+
  void vhost_poll_queue(struct vhost_poll *poll)
  {
+     set_bit(poll->poll_id, poll->dev->work_pending);
      vhost_work_queue(poll->dev, &poll->work);
  }
  EXPORT_SYMBOL_GPL(vhost_poll_queue);

@@ -354,6 +363,7 @@ static int vhost_worker(void *data)
              if (!node)
                      schedule();

+             bitmap_zero(dev->work_pending, VHOST_DEV_MAX_VQ);
              node = llist_reverse_order(node);
              /* make sure flag is seen after deletion */
              smp_wmb();

@@ -420,6 +430,8 @@ void vhost_dev_init(struct vhost_dev *dev,
      struct vhost_virtqueue *vq;
      int i;

+     BUG_ON(nvqs > VHOST_DEV_MAX_VQ);
+
      dev->vqs = vqs;
      dev->nvqs = nvqs;
      mutex_init(&dev->mutex);

@@ -428,6 +440,7 @@ void vhost_dev_init(struct vhost_dev *dev,
      dev->iotlb = NULL;
      dev->mm = NULL;
      dev->worker = NULL;
+     bitmap_zero(dev->work_pending, VHOST_DEV_MAX_VQ);
      init_llist_head(&dev->work_list);
      init_waitqueue_head(&dev->wait);
      INIT_LIST_HEAD(&dev->read_list);

@@ -445,7 +458,7 @@ void vhost_dev_init(struct vhost_dev *dev,
              vhost_vq_reset(dev, vq);
              if (vq->handle_kick)
                      vhost_poll_init(&vq->poll, vq->handle_kick,
-                                     EPOLLIN, dev);
+                                     i, EPOLLIN, dev);
      }
  }
  EXPORT_SYMBOL_GPL(vhost_dev_init);

diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 6c844b9..60b6f6d 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h

@@ -30,6 +30,7 @@ struct vhost_poll {
      wait_queue_head_t        *wqh;
      wait_queue_entry_t              wait;
      struct vhost_work         work;
+     __u8                      poll_id;
      __poll_t                  mask;
      struct vhost_dev         *dev;
  };

@@ -37,9 +38,10 @@ struct vhost_poll {
  void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn);
  void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work);
  bool vhost_has_work(struct vhost_dev *dev);
+bool vhost_has_work_pending(struct vhost_dev *dev, int poll_id);

  void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
-                  __poll_t mask, struct vhost_dev *dev);
+                  __u8 id, __poll_t mask, struct vhost_dev *dev);
  int vhost_poll_start(struct vhost_poll *poll, struct file *file);
  void vhost_poll_stop(struct vhost_poll *poll);
  void vhost_poll_flush(struct vhost_poll *poll);

@@ -152,6 +154,8 @@ struct vhost_msg_node {
    struct list_head node;
  };

+#define VHOST_DEV_MAX_VQ     128
+
  struct vhost_dev {
      struct mm_struct *mm;
      struct mutex mutex;

@@ -159,6 +163,7 @@ struct vhost_dev {
      int nvqs;
      struct eventfd_ctx *log_ctx;
      struct llist_head work_list;
+     DECLARE_BITMAP(work_pending, VHOST_DEV_MAX_VQ);
      struct task_struct *worker;
      struct vhost_umem *umem;
      struct vhost_umem *iotlb;

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