Re: [libvirt] [PATCH] qemu: do not ask for balloon information if not used

On Thu, Aug 12, 2010 at 02:07:41PM +0200, Daniel Veillard wrote: > Basically a followup of the previous patch about balloon desactivation > if desactivated, to not ask for balloon information to qemu as we will > just get an error back. > This can make a huge difference in the time needed for domain > information or list when a machine is loaded, and balloon has been > desactivated in the guests. > > Note that the patch does a check in the GetDomainInfo function, to avoid > checking for job, getting a job, getting the monitor lock and cleaning > back which would be added operations if I had done this one level > down in qemuMonitorGetBalloonInfo() > The qemudDomainDumpXML() function also call qemuMonitorGetBalloonInfo() > so maybe the check should be duplicated there, I left that out of the > patch for now as this is an operation which sounds less time critical. > Or maybe the test should be added to qemuMonitorGetBalloonInfo() too > since it's exported from src/qemu/qemu_monitor.h and may end up being > used from other places in the future, Nah, putting it in qemu_driver is the correct place. The qemu_monitor.h files are designed to not have any awareness of the virDomainDef structures - just simple commaands to talk to the monitor. We should add the same to DumpXML as you say.