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. Michal -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list
