On Wed, Apr 05, 2017 at 05:27:58PM +0800, jemmy858...@gmail.com wrote: > From: Lidong Chen <lidongc...@tencent.com> > > when migration with high speed, mig_save_device_bulk invoke > bdrv_is_allocated too frequently, and cause vnc reponse slowly. > this patch limit the time used for bdrv_is_allocated.
Can you explain why calling bdrv_is_allocated is impacting VNC performance ? Migration is running in a background thread, so shouldn't be impacting the main thread which handles VNC, unless the block layer is perhaps acquiring the global qemu lock ? I wouldn't expect such a lock to be held for just the bdrv_is_allocated call though. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://entangle-photo.org -o- http://search.cpan.org/~danberr/ :|
