Microsoft SQL Server - Defect ID: 2410400

SOS_BLOCKALLOCPARTIALLIST spinlock contention and elevated CPU utilization occur on large-memory machines. DBCC DROPCLEANBUFFERS provides temporary mitigation for this issue when encountered. This occurs when multiple threads concurrently attempt to gain access to a spinlock-protected list used by the SQL operating system for memory management purposes. The following trace flags are required to enable the fix: - TF 8142 partitions list by count of CPU, up to 64 partitions - TF 8145 modifies the partitioning to be count of soft-NUMA nodes These trace flags must be applied as startup parameters to take effect. If SOS_BLOCKALLOCPARTIALLIST spinlock contention is encountered and DBCC DROPCLEANBUFFERS provides temporary mitigation, it's recommended to apply this fix first with both trace flags, and remove Trace Flag 8145 only if symptoms persist.