On Mon, May 29, 2017 at 02:16:17PM +0200, Michal Privoznik wrote: > On 05/19/2017 03:16 PM, Erik Skultety wrote: > > From: "ning.bo" <ning.bo9@xxxxxxxxxx> > > > > When a number of SRIOV VFs (up to 128 on Intel XL710) is created: > > for i in `seq 0 1`; do > > echo 63 > /sys/class/net/<interface>/device/sriov_numvfs > > done > > > > libvirtd will then report "udev_monitor_receive_device returned NULL" > > error because the netlink socket buffer is not big enough (using GDB on > > libudev confirmed this with ENOBUFFS) and thus some udev events were > > dropped. This results in some devices being missing in the nodedev-list > > output. This patch overrides the system's rmem_max limit but for that, > > we need to make sure we've got root privileges. > > > > https://bugzilla.redhat.com/show_bug.cgi?id=1450960 > > > > Signed-off-by: ning.bo <ning.bo9@xxxxxxxxxx> > > Signed-off-by: Erik Skultety <eskultet@xxxxxxxxxx> > > --- > > Additionally, we might want to check for the errno, providing a specific > > message if such issue occurs again in a further non-specified point in time and > > return the generic, yet cryptic one for all other cases. > > > > src/node_device/node_device_udev.c | 7 +++++++ > > 1 file changed, 7 insertions(+) > > > > diff --git a/src/node_device/node_device_udev.c b/src/node_device/node_device_udev.c > > index 4ecb0b18f..0b3717397 100644 > > --- a/src/node_device/node_device_udev.c > > +++ b/src/node_device/node_device_udev.c > > @@ -1728,6 +1728,13 @@ static int nodeStateInitialize(bool privileged, > > > > udev_monitor_enable_receiving(priv->udev_monitor); > > > > + /* mimic udevd's behaviour and override the systems rmem_max limit in case > > + * there's a significant number of device 'add' events > > + */ > > + if (geteuid() == 0) > > + udev_monitor_set_receive_buffer_size(priv->udev_monitor, > > + 128 * 1024 * 1024); > > + > > /* We register the monitor with the event callback so we are > > * notified by udev of device changes before we enumerate existing > > * devices because libvirt will simply recreate the device if we > > ACK and safe for freeze. Although on my system it works even without the > check for euid. Are you sure? Because the session daemon should not have the CAP_NET_ADMIN capability. Though it's true that since we don't care about the return value the check is unnecessary I give you that. Still, the check is harmless and we know that it will fail for non-privileged user, so I'm going to keep it here. Thanks for review, Erik > > Michal > > -- > libvir-list mailing list > libvir-list@xxxxxxxxxx > https://www.redhat.com/mailman/listinfo/libvir-list -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list
