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[RFC 2/7] vhost: Add kthread support in function vhost_worker_queue()

Cindy Lu posted 7 patches 1 year, 5 months ago
There is a newer version of this series
[RFC 2/7] vhost: Add kthread support in function vhost_worker_queue()
Posted by Cindy Lu 1 year, 5 months ago 
Added back the previously removed function vhost_worker_queue() and
renamed it to vhost_worker_queue_khtread(). The new vhost_worker_queue()
will select the different mode based on the value of the parameter.

Signed-off-by: Cindy Lu <lulu@redhat.com>
---
 drivers/vhost/vhost.c | 30 ++++++++++++++++++++++++++++--
 drivers/vhost/vhost.h |  1 +
 2 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index da701f6b3f2c..6261c9df468e 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -236,8 +236,8 @@ void vhost_poll_stop(struct vhost_poll *poll)
 }
 EXPORT_SYMBOL_GPL(vhost_poll_stop);
 
-static void vhost_worker_queue(struct vhost_worker *worker,
-			       struct vhost_work *work)
+static void vhost_worker_queue_task(struct vhost_worker *worker,
+				    struct vhost_work *work)
 {
 	if (!test_and_set_bit(VHOST_WORK_QUEUED, &work->flags)) {
 		/* We can only add the work to the list after we're
@@ -249,6 +249,32 @@ static void vhost_worker_queue(struct vhost_worker *worker,
 	}
 }
 
+static void vhost_work_queue_kthread(struct vhost_worker *worker,
+				     struct vhost_work *work)
+{
+	if (!worker)
+		return;
+
+	if (!test_and_set_bit(VHOST_WORK_QUEUED, &work->flags)) {
+		/* We can only add the work to the list after we're
+		 * sure it was not in the list.
+		 * test_and_set_bit() implies a memory barrier.
+		 */
+		llist_add(&work->node, &worker->work_list);
+
+		wake_up_process(worker->task);
+	}
+}
+
+static void vhost_worker_queue(struct vhost_worker *worker,
+			       struct vhost_work *work)
+{
+	if (use_kthread) {
+		vhost_work_queue_kthread(worker, work);
+	} else {
+		vhost_worker_queue_task(worker, work);
+	}
+}
 bool vhost_vq_work_queue(struct vhost_virtqueue *vq, struct vhost_work *work)
 {
 	struct vhost_worker *worker;
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index bb75a292d50c..c7f126fd09e8 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -27,6 +27,7 @@ struct vhost_work {
 };
 
 struct vhost_worker {
+	struct task_struct	*task;
 	struct vhost_task	*vtsk;
 	struct vhost_dev	*dev;
 	/* Used to serialize device wide flushing with worker swapping. */
-- 
2.45.0
Re: [RFC 2/7] vhost: Add kthread support in function vhost_worker_queue()
Posted by Jason Wang 1 year, 5 months ago 
On Mon, Aug 19, 2024 at 5:29 PM Cindy Lu <lulu@redhat.com> wrote:
>
> Added back the previously removed function vhost_worker_queue() and
> renamed it to vhost_worker_queue_khtread(). The new vhost_worker_queue()
> will select the different mode based on the value of the parameter.
>
> Signed-off-by: Cindy Lu <lulu@redhat.com>

It looks like a partial revert of some previous commit, please mention
the commit id in the change log as least.

So did for the following 3 or 4 patches.

Thanks

> ---
>  drivers/vhost/vhost.c | 30 ++++++++++++++++++++++++++++--
>  drivers/vhost/vhost.h |  1 +
>  2 files changed, 29 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index da701f6b3f2c..6261c9df468e 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -236,8 +236,8 @@ void vhost_poll_stop(struct vhost_poll *poll)
>  }
>  EXPORT_SYMBOL_GPL(vhost_poll_stop);
>
> -static void vhost_worker_queue(struct vhost_worker *worker,
> -                              struct vhost_work *work)
> +static void vhost_worker_queue_task(struct vhost_worker *worker,
> +                                   struct vhost_work *work)
>  {
>         if (!test_and_set_bit(VHOST_WORK_QUEUED, &work->flags)) {
>                 /* We can only add the work to the list after we're
> @@ -249,6 +249,32 @@ static void vhost_worker_queue(struct vhost_worker *worker,
>         }
>  }
>
> +static void vhost_work_queue_kthread(struct vhost_worker *worker,
> +                                    struct vhost_work *work)
> +{
> +       if (!worker)
> +               return;
> +
> +       if (!test_and_set_bit(VHOST_WORK_QUEUED, &work->flags)) {
> +               /* We can only add the work to the list after we're
> +                * sure it was not in the list.
> +                * test_and_set_bit() implies a memory barrier.
> +                */
> +               llist_add(&work->node, &worker->work_list);
> +
> +               wake_up_process(worker->task);
> +       }
> +}
> +
> +static void vhost_worker_queue(struct vhost_worker *worker,
> +                              struct vhost_work *work)
> +{
> +       if (use_kthread) {
> +               vhost_work_queue_kthread(worker, work);
> +       } else {
> +               vhost_worker_queue_task(worker, work);
> +       }
> +}
>  bool vhost_vq_work_queue(struct vhost_virtqueue *vq, struct vhost_work *work)
>  {
>         struct vhost_worker *worker;
> diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
> index bb75a292d50c..c7f126fd09e8 100644
> --- a/drivers/vhost/vhost.h
> +++ b/drivers/vhost/vhost.h
> @@ -27,6 +27,7 @@ struct vhost_work {
>  };
>
>  struct vhost_worker {
> +       struct task_struct      *task;
>         struct vhost_task       *vtsk;
>         struct vhost_dev        *dev;
>         /* Used to serialize device wide flushing with worker swapping. */
> --
> 2.45.0
>
Re: [RFC 2/7] vhost: Add kthread support in function vhost_worker_queue()
Posted by Cindy Lu 1 year, 5 months ago 
On Tue, 27 Aug 2024 at 10:36, Jason Wang <jasowang@redhat.com> wrote:
>
> On Mon, Aug 19, 2024 at 5:29 PM Cindy Lu <lulu@redhat.com> wrote:
> >
> > Added back the previously removed function vhost_worker_queue() and
> > renamed it to vhost_worker_queue_khtread(). The new vhost_worker_queue()
> > will select the different mode based on the value of the parameter.
> >
> > Signed-off-by: Cindy Lu <lulu@redhat.com>
>
> It looks like a partial revert of some previous commit, please mention
> the commit id in the change log as least.
>
> So did for the following 3 or 4 patches.
>
> Thanks
>
sure, will add this
Thanks
cindy
> > ---
> >  drivers/vhost/vhost.c | 30 ++++++++++++++++++++++++++++--
> >  drivers/vhost/vhost.h |  1 +
> >  2 files changed, 29 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> > index da701f6b3f2c..6261c9df468e 100644
> > --- a/drivers/vhost/vhost.c
> > +++ b/drivers/vhost/vhost.c
> > @@ -236,8 +236,8 @@ void vhost_poll_stop(struct vhost_poll *poll)
> >  }
> >  EXPORT_SYMBOL_GPL(vhost_poll_stop);
> >
> > -static void vhost_worker_queue(struct vhost_worker *worker,
> > -                              struct vhost_work *work)
> > +static void vhost_worker_queue_task(struct vhost_worker *worker,
> > +                                   struct vhost_work *work)
> >  {
> >         if (!test_and_set_bit(VHOST_WORK_QUEUED, &work->flags)) {
> >                 /* We can only add the work to the list after we're
> > @@ -249,6 +249,32 @@ static void vhost_worker_queue(struct vhost_worker *worker,
> >         }
> >  }
> >
> > +static void vhost_work_queue_kthread(struct vhost_worker *worker,
> > +                                    struct vhost_work *work)
> > +{
> > +       if (!worker)
> > +               return;
> > +
> > +       if (!test_and_set_bit(VHOST_WORK_QUEUED, &work->flags)) {
> > +               /* We can only add the work to the list after we're
> > +                * sure it was not in the list.
> > +                * test_and_set_bit() implies a memory barrier.
> > +                */
> > +               llist_add(&work->node, &worker->work_list);
> > +
> > +               wake_up_process(worker->task);
> > +       }
> > +}
> > +
> > +static void vhost_worker_queue(struct vhost_worker *worker,
> > +                              struct vhost_work *work)
> > +{
> > +       if (use_kthread) {
> > +               vhost_work_queue_kthread(worker, work);
> > +       } else {
> > +               vhost_worker_queue_task(worker, work);
> > +       }
> > +}
> >  bool vhost_vq_work_queue(struct vhost_virtqueue *vq, struct vhost_work *work)
> >  {
> >         struct vhost_worker *worker;
> > diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
> > index bb75a292d50c..c7f126fd09e8 100644
> > --- a/drivers/vhost/vhost.h
> > +++ b/drivers/vhost/vhost.h
> > @@ -27,6 +27,7 @@ struct vhost_work {
> >  };
> >
> >  struct vhost_worker {
> > +       struct task_struct      *task;
> >         struct vhost_task       *vtsk;
> >         struct vhost_dev        *dev;
> >         /* Used to serialize device wide flushing with worker swapping. */
> > --
> > 2.45.0
> >
>

Patchew 2.1-devel-b67e4c2

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