Addresses https://github.com/valkey-io/valkey/issues/1393
Changes:
* During AOF loading or long running script, this allows defrag to be
initiated.
* The AOF defrag test was corrected to eliminate the wait period and
rely on non-timer invocations.
* Logic for "overage" time in defrag was changed. It previously
accumulated underage leading to large latencies in extreme tests having
very high CPU percentage. After several simple stages were completed
during infrequent blocked processing, a large cycle time would be
experienced.
Signed-off-by: Jim Brunner <brunnerj@amazon.com>
0c8ad5cd34