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virtio_balloon: Treat stats requests as wakeup events

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Treat stats requests as wakeup events to ensure that the driver responds
to device requests in a timely manner.

Signed-off-by: David Stevens <stevensd@chromium.org>
Acked-by: David Hildenbrand <david@redhat.com>
Message-Id: <20240321012445.1593685-3-stevensd@google.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
David Stevens 2024-03-21 10:24:45 +09:00 committed by Michael S. Tsirkin
parent 810d831bbb
commit c578123e63
1 changed files with 46 additions and 29 deletions
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75
drivers/virtio/virtio_balloon.c
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@ -121,11 +121,14 @@ struct virtio_balloon {
struct page_reporting_dev_info pr_dev_info;
/* State for keeping the wakeup_source active while adjusting the balloon */
spinlock_t adjustment_lock;
bool adjustment_signal_pending;
bool adjustment_in_progress;
spinlock_t wakeup_lock;
bool processing_wakeup_event;
u32 wakeup_signal_mask;
};
#define VIRTIO_BALLOON_WAKEUP_SIGNAL_ADJUST (1 << 0)
#define VIRTIO_BALLOON_WAKEUP_SIGNAL_STATS (1 << 1)
static const struct virtio_device_id id_table[] = {
{ VIRTIO_ID_BALLOON, VIRTIO_DEV_ANY_ID },
{ 0 },
@ -140,6 +143,36 @@ static u32 page_to_balloon_pfn(struct page *page)
return pfn * VIRTIO_BALLOON_PAGES_PER_PAGE;
}
static void start_wakeup_event(struct virtio_balloon *vb, u32 mask)
{
unsigned long flags;
spin_lock_irqsave(&vb->wakeup_lock, flags);
vb->wakeup_signal_mask |= mask;
if (!vb->processing_wakeup_event) {
vb->processing_wakeup_event = true;
pm_stay_awake(&vb->vdev->dev);
}
spin_unlock_irqrestore(&vb->wakeup_lock, flags);
}
static void process_wakeup_event(struct virtio_balloon *vb, u32 mask)
{
spin_lock_irq(&vb->wakeup_lock);
vb->wakeup_signal_mask &= ~mask;
spin_unlock_irq(&vb->wakeup_lock);
}
static void finish_wakeup_event(struct virtio_balloon *vb)
{
spin_lock_irq(&vb->wakeup_lock);
if (!vb->wakeup_signal_mask && vb->processing_wakeup_event) {
vb->processing_wakeup_event = false;
pm_relax(&vb->vdev->dev);
}
spin_unlock_irq(&vb->wakeup_lock);
}
static void balloon_ack(struct virtqueue *vq)
{
struct virtio_balloon *vb = vq->vdev->priv;
@ -370,8 +403,10 @@ static void stats_request(struct virtqueue *vq)
struct virtio_balloon *vb = vq->vdev->priv;
spin_lock(&vb->stop_update_lock);
if (!vb->stop_update)
if (!vb->stop_update) {
start_wakeup_event(vb, VIRTIO_BALLOON_WAKEUP_SIGNAL_STATS);
queue_work(system_freezable_wq, &vb->update_balloon_stats_work);
}
spin_unlock(&vb->stop_update_lock);
}
@ -444,29 +479,10 @@ static void virtio_balloon_queue_free_page_work(struct virtio_balloon *vb)
static void start_update_balloon_size(struct virtio_balloon *vb)
{
unsigned long flags;
spin_lock_irqsave(&vb->adjustment_lock, flags);
vb->adjustment_signal_pending = true;
if (!vb->adjustment_in_progress) {
vb->adjustment_in_progress = true;
pm_stay_awake(&vb->vdev->dev);
}
spin_unlock_irqrestore(&vb->adjustment_lock, flags);
start_wakeup_event(vb, VIRTIO_BALLOON_WAKEUP_SIGNAL_ADJUST);
queue_work(system_freezable_wq, &vb->update_balloon_size_work);
}
static void end_update_balloon_size(struct virtio_balloon *vb)
{
spin_lock_irq(&vb->adjustment_lock);
if (!vb->adjustment_signal_pending && vb->adjustment_in_progress) {
vb->adjustment_in_progress = false;
pm_relax(&vb->vdev->dev);
}
spin_unlock_irq(&vb->adjustment_lock);
}
static void virtballoon_changed(struct virtio_device *vdev)
{
struct virtio_balloon *vb = vdev->priv;
@ -495,7 +511,10 @@ static void update_balloon_stats_func(struct work_struct *work)
vb = container_of(work, struct virtio_balloon,
update_balloon_stats_work);
process_wakeup_event(vb, VIRTIO_BALLOON_WAKEUP_SIGNAL_STATS);
stats_handle_request(vb);
finish_wakeup_event(vb);
}
static void update_balloon_size_func(struct work_struct *work)
@ -506,9 +525,7 @@ static void update_balloon_size_func(struct work_struct *work)
vb = container_of(work, struct virtio_balloon,
update_balloon_size_work);
spin_lock_irq(&vb->adjustment_lock);
vb->adjustment_signal_pending = false;
spin_unlock_irq(&vb->adjustment_lock);
process_wakeup_event(vb, VIRTIO_BALLOON_WAKEUP_SIGNAL_ADJUST);
diff = towards_target(vb);
@ -523,7 +540,7 @@ static void update_balloon_size_func(struct work_struct *work)
if (diff)
queue_work(system_freezable_wq, work);
else
end_update_balloon_size(vb);
finish_wakeup_event(vb);
}
static int init_vqs(struct virtio_balloon *vb)
@ -1027,7 +1044,7 @@ static int virtballoon_probe(struct virtio_device *vdev)
goto out_unregister_oom;
}
spin_lock_init(&vb->adjustment_lock);
spin_lock_init(&vb->wakeup_lock);
/*
* The virtio balloon itself can't wake up the device, but it is