From: "Michael S. Tsirkin" <mst@redhat.com>
To: Petr Mladek <pmladek@suse.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>,
Jeff Epler <jepler@unpythonic.net>, Tejun Heo <tj@kernel.org>,
Jiri Kosina <jkosina@suse.cz>,
virtualization@lists.linux-foundation.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 1/2] virtio_balloon: Restore the entire balloon after the system freeze
Date: Fri, 1 Jan 2016 12:11:02 +0200 [thread overview]
Message-ID: <20160101115424-mutt-send-email-mst@redhat.com> (raw)
In-Reply-To: <1449236271-10133-2-git-send-email-pmladek@suse.com>
On Fri, Dec 04, 2015 at 02:37:50PM +0100, Petr Mladek wrote:
> fill_balloon() and leak_balloon() manipulate only a limited number
> of pages in one call. This is the reason why remove_common() calls
> leak_balloon() in a while cycle.
>
> remove_common() is called also when the system is being frozen.
> But fill_balloon() is called only once when the system is being
> restored. It means that most of the balloon stays leaked after
> the system freeze and restore.
Right, but refilling might take a long while.
In fact, we sleep for 200msec on refill failure,
stalling system resume - which is already a bug.
> This patch adds the missing while cycle also into virtballoon_restore().
> Also it makes fill_balloon() to return the number of really modified
> pages. Note that leak_balloon() already did this.
>
> Signed-off-by: Petr Mladek <pmladek@suse.com>
This is a replacement for:
virtio_balloon: Restore the entire balloon after the system freeze
> ---
> drivers/virtio/virtio_balloon.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
> index 7efc32945810..d73a86db2490 100644
> --- a/drivers/virtio/virtio_balloon.c
> +++ b/drivers/virtio/virtio_balloon.c
> @@ -135,9 +135,10 @@ static void set_page_pfns(u32 pfns[], struct page *page)
> pfns[i] = page_to_balloon_pfn(page) + i;
> }
>
> -static void fill_balloon(struct virtio_balloon *vb, size_t num)
> +static unsigned fill_balloon(struct virtio_balloon *vb, size_t num)
> {
> struct balloon_dev_info *vb_dev_info = &vb->vb_dev_info;
> + unsigned num_allocated_pages;
>
> /* We can only do one array worth at a time. */
> num = min(num, ARRAY_SIZE(vb->pfns));
> @@ -162,10 +163,13 @@ static void fill_balloon(struct virtio_balloon *vb, size_t num)
> adjust_managed_page_count(page, -1);
> }
>
> + num_allocated_pages = vb->num_pfns;
> /* Did we get any? */
> if (vb->num_pfns != 0)
> tell_host(vb, vb->inflate_vq);
> mutex_unlock(&vb->balloon_lock);
> +
> + return num_allocated_pages;
> }
>
> static void release_pages_balloon(struct virtio_balloon *vb)
> @@ -581,6 +585,7 @@ static int virtballoon_freeze(struct virtio_device *vdev)
> static int virtballoon_restore(struct virtio_device *vdev)
> {
> struct virtio_balloon *vb = vdev->priv;
> + s64 diff;
> int ret;
>
> ret = init_vqs(vdev->priv);
> @@ -589,7 +594,9 @@ static int virtballoon_restore(struct virtio_device *vdev)
>
> virtio_device_ready(vdev);
>
> - fill_balloon(vb, towards_target(vb));
> + diff = towards_target(vb);
> + while (diff > 0)
> + diff -= fill_balloon(vb, diff);
> update_balloon_size(vb);
> return 0;
> }
> --
> 1.8.5.6
next prev parent reply other threads:[~2016-01-01 10:11 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-04 13:37 [PATCH v4 0/2] virtio_balloon: Fix restore and convert to workqueue Petr Mladek
2015-12-04 13:37 ` [PATCH v4 1/2] virtio_balloon: Restore the entire balloon after the system freeze Petr Mladek
2016-01-01 10:11 ` Michael S. Tsirkin [this message]
2016-01-01 10:11 ` Michael S. Tsirkin
2015-12-04 13:37 ` [PATCH v4 2/2] virtio_balloon: Use a workqueue instead of "vballoon" kthread Petr Mladek
2016-01-01 10:18 ` Michael S. Tsirkin
2016-01-02 11:43 ` Tejun Heo
2016-01-02 21:36 ` Michael S. Tsirkin
2016-01-03 13:58 ` Tejun Heo
2016-01-05 14:49 ` Petr Mladek
2016-01-05 15:37 ` Michael S. Tsirkin
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