From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=59095 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OvbGo-0003WC-Vp for qemu-devel@nongnu.org; Tue, 14 Sep 2010 15:34:23 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OvbGn-0000JO-Ln for qemu-devel@nongnu.org; Tue, 14 Sep 2010 15:34:22 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52653) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OvbGn-0000JI-Em for qemu-devel@nongnu.org; Tue, 14 Sep 2010 15:34:21 -0400 Date: Tue, 14 Sep 2010 16:34:16 -0300 From: Luiz Capitulino Subject: Re: [Qemu-devel] [PATCH] disable guest-provided stats on "info balloon" command Message-ID: <20100914163416.1c699759@doriath> In-Reply-To: <1284482619-3948-1-git-send-email-ehabkost@redhat.com> References: <1284482619-3948-1-git-send-email-ehabkost@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eduardo Habkost Cc: Amit Shah , Paolo Bonzini , Adam Litke , qemu-devel@nongnu.org, Markus Armbruster On Tue, 14 Sep 2010 13:43:39 -0300 Eduardo Habkost wrote: > The addition of memory stats reporting to the virtio balloon causes > the 'info balloon' command to become asynchronous. This is a regression > because in some cases it can hang the user monitor. > > This is an alternative to Adam Litke's patch. Adam's patch disabled the > corresponding (guest-visible) virtio feature bit, causing issues for migration. > Original discussion is available at: > http://marc.info/?l=qemu-devel&m=128448124328314&w=2 > > Signed-off-by: Eduardo Habkost > Acked-by: Adam Litke > --- > diff --git a/hw/virtio-balloon.c b/hw/virtio-balloon.c > index 1e4dfdd..92e9057 100644 > --- a/hw/virtio-balloon.c > +++ b/hw/virtio-balloon.c > @@ -30,6 +30,10 @@ > #include > #endif > > +/* Disable guest-provided stats by now (https://bugzilla.redhat.com/show_bug.cgi?id=623903) */ > +#define ENABLE_GUEST_STATS 0 > + > + > typedef struct VirtIOBalloon > { > VirtIODevice vdev; > @@ -84,12 +88,14 @@ static QObject *get_stats_qobject(VirtIOBalloon *dev) > VIRTIO_BALLOON_PFN_SHIFT); > > stat_put(dict, "actual", actual); > +#if ENABLE_GUEST_STATS > stat_put(dict, "mem_swapped_in", dev->stats[VIRTIO_BALLOON_S_SWAP_IN]); > stat_put(dict, "mem_swapped_out", dev->stats[VIRTIO_BALLOON_S_SWAP_OUT]); > stat_put(dict, "major_page_faults", dev->stats[VIRTIO_BALLOON_S_MAJFLT]); > stat_put(dict, "minor_page_faults", dev->stats[VIRTIO_BALLOON_S_MINFLT]); > stat_put(dict, "free_mem", dev->stats[VIRTIO_BALLOON_S_MEMFREE]); > stat_put(dict, "total_mem", dev->stats[VIRTIO_BALLOON_S_MEMTOT]); > +#endif > > return QOBJECT(dict); > } > @@ -215,7 +221,7 @@ static void virtio_balloon_to_target(void *opaque, ram_addr_t target, > } > dev->stats_callback = cb; > dev->stats_opaque_callback_data = cb_data; > - if (dev->vdev.guest_features & (1 << VIRTIO_BALLOON_F_STATS_VQ)) { > + if (ENABLE_GUEST_STATS && (dev->vdev.guest_features & (1 << VIRTIO_BALLOON_F_STATS_VQ))) { > virtqueue_push(dev->svq, &dev->stats_vq_elem, dev->stats_vq_offset); > virtio_notify(&dev->vdev, dev->svq); > } else { >