On Fri, Nov 17, 2017 at 18:17:31 -0500, John Ferlan wrote:
https://bugzilla.redhat.com/show_bug.cgi?id=916061
If the QEMU version running is new enough (based on QEMU_CAPS_QUERY_DUMP) we can add a 'detach' boolean to the dump-guest-memory command in order to tell QEMU to run in a thread. Then, use the qemuDumpWaitForCompletion in order to 'watch' the dump and save the stats into the jobInfo data so that tools (such as virsh) can pick up and display the completion percentage. The processing is similar to qemuMigrationWaitForCompletion at least with respect to calling the query-dump in a while loop that gets a micro sleep in order for qemuDomainGetJobInfo to be able to pull out the changed migration stats values.
Looks like the code was inspired by our old migration flow with a lot of copy&paste work. However, I don't think this is necessary. Does QEMU provide any event when a detached dump completes? If so, we should use it. If QEMU does not provide the event, I think we should only add support for detached dump once the event is implemented in QEMU. In other words, we should never poll for dump progress every 50ms. Jirka