Workaround: Restarting the server would ease the allocation manager contention since the internal allocation hash table gets resized based on the new partition count in the database.
Service pack informationThis issue was first fixed in the following Service Pack/CUs for SQL Server.
Service Pack 2 for SQL Server 2014
Cumulative Update 1 for SQL Server 2016
About Service packs for SQL Server
Service packs are cumulative. Each new service pack contains all the fixes that are in previous service packs, together with any new fixes. Our recommendation is to apply the latest service pack and the latest cumulative update for that service pack. You don't have to install a previous service pack before you install the latest service pack. Use Table 1 in the following article for finding more information about the latest service pack and latest cumulative update.
How to determine the version, edition and update level of SQL Server and its components?
Article ID: 3173767 - Last Review: Jul 25, 2016 - Revision: 1