From: Raushaniya Maksudova <rmaksudova@xxxxxxxxxxxxx>
This value would be useful in the next patch to provide the amount of
the freed memory for OOM killer.
Accessing to vb->num_pfns outside of vb->balloon_lock is wrong and unsafe.
Signed-off-by: Raushaniya Maksudova <rmaksudova@xxxxxxxxxxxxx>
Signed-off-by: Denis V. Lunev <den@xxxxxxxxxx>
CC: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
CC: Michael S. Tsirkin <mst@xxxxxxxxxx>
CC: virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
---
drivers/virtio/virtio_balloon.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index 25ebe8e..213da41 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -168,8 +168,9 @@ static void release_pages_by_pfn(const u32 pfns[], unsigned int num)
}
}
-static void leak_balloon(struct virtio_balloon *vb, size_t num)
+static unsigned leak_balloon(struct virtio_balloon *vb, size_t num)
{
+ unsigned num_freed_pages;
struct page *page;
struct balloon_dev_info *vb_dev_info = vb->vb_dev_info;
@@ -186,6 +187,7 @@ static void leak_balloon(struct virtio_balloon *vb, size_t num)
vb->num_pages -= VIRTIO_BALLOON_PAGES_PER_PAGE;
}
+ num_freed_pages = vb->num_pfns;
/*
* Note that if
* virtio_has_feature(vdev, VIRTIO_BALLOON_F_MUST_TELL_HOST);
@@ -195,6 +197,7 @@ static void leak_balloon(struct virtio_balloon *vb, size_t num)
tell_host(vb, vb->deflate_vq);
mutex_unlock(&vb->balloon_lock);
release_pages_by_pfn(vb->pfns, vb->num_pfns);
+ return num_freed_pages;
}
static inline void update_stat(struct virtio_balloon *vb, int idx,
--
1.9.1
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