Comment 9 for bug 1254872

I faced the same issue on http://logs.openstack.org/97/71197/2/gate/gate-tempest-dsvm-full/7498458/logs/ .

The operation of update_available_resource() was stalled on n-cpu process with having the semaphore "compute_resources" in long time due to this problem.
And all "create a server" operations failed because the operations could not get the semaphore "compute_resources".

Current e-r query of this problem cannot catch it now, and I have posted the patch for it.
https://review.openstack.org/#/c/74925/