From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH v1 1/3] virtio-balloon: Fix memory leak when unloading while hinting is in progress Date: Thu, 6 Feb 2020 03:36:26 -0500 Message-ID: <20200206033617-mutt-send-email-mst@kernel.org> References: <20200205163402.42627-1-david@redhat.com> <20200205163402.42627-2-david@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20200205163402.42627-2-david@redhat.com> Sender: linux-kernel-owner@vger.kernel.org To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, virtualization@lists.linux-foundation.org, Jason Wang , Wei Wang , Liang Li List-Id: virtualization@lists.linuxfoundation.org On Wed, Feb 05, 2020 at 05:34:00PM +0100, David Hildenbrand wrote: > When unloading the driver while hinting is in progress, we will not > release the free page blocks back to MM, resulting in a memory leak. > > Fixes: 86a559787e6f ("virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT") > Cc: "Michael S. Tsirkin" > Cc: Jason Wang > Cc: Wei Wang > Cc: Liang Li > Signed-off-by: David Hildenbrand Applied, thanks! > --- > drivers/virtio/virtio_balloon.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c > index 8e400ece9273..abef2306c899 100644 > --- a/drivers/virtio/virtio_balloon.c > +++ b/drivers/virtio/virtio_balloon.c > @@ -968,6 +968,10 @@ static void remove_common(struct virtio_balloon *vb) > leak_balloon(vb, vb->num_pages); > update_balloon_size(vb); > > + /* There might be free pages that are being reported: release them. */ > + if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) > + return_free_pages_to_mm(vb, ULONG_MAX); > + > /* Now we reset the device so we can clean up the queues. */ > vb->vdev->config->reset(vb->vdev); > > -- > 2.24.1