|
Thanks Daniel for the info. But I still have a question, since
we already make the call qemudDomainCreate
synced, why do we need to introduce a bitmap to resolve the problem of getting
VNC port conflict error? If qemudDomainCreate
is synced, then there should not any problem with VNC port. Looking forward to your reply. static virDomainPtr
qemudDomainCreate(virConnectPtr conn, const char *xml,
unsigned int flags) { struct qemud_driver
*driver = conn->privateData; virDomainDefPtr def; virDomainObjPtr vm =
NULL; virDomainPtr dom = NULL; virDomainEventPtr event
= NULL;
virCheckFlags(VIR_DOMAIN_START_PAUSED, NULL); qemuDriverLock(driver); <== Thanks, Guangya -----Original Message----- On Sun, Nov 07, 2010 at 08:53:32PM +0800, Guangya Liu
wrote: > Hi, > > > > We are encountering a problem of race conditions
for getting VNC port > when VM start up. > > > > In a very powerful hypervisor, if we try to start
up more than 1 VM > concurrently, then there might be some VMs failed
to start up due to VNC > port confilict. > > > > We searched libvirt bugs and found that some one
report the problem and > we have give a fix, but the fix can not resolve
the problem. > > > >
http://osdir.com/ml/libvir-list/2010-05/msg00530.html > >
https://build.opensuse.org/package/view_file?file=vnc-race-3.patch&packa > ge=libvirt&project=Virtualization:openSUSE11.3 This patch is already merged in current GIT repos. > The bitmap test-and-set operation is not atomic,
so that there still is > a time-window in which a VNC port could be
reserved for two caller. The virBitmap APIs for getting & setting don't need
to be atomic, because they are only called when the QEMU driver mutex is
held, which ensures serialization of VM startup. Regards, Daniel -- |: Red Hat, Engineering, |: http://libvirt.org -o- http://virt-manager.org -o-
http://deltacloud.org :| |: http://autobuild.org -o-
http://search.cpan.org/~danberr/ :| |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1
B3DF F742 7D3B 9505 :| |
-- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list