Cache Spinlock Contention

Number of times an engine encountered spinlock contention on the cache, and had to wait, as a percentage of the total spinlock requests for that cache. This is meaningful only in SMP environments.

When a user task makes any changes to a cache, a spinlock denies all other tasks access to the cache while the changes are being made. Although spinlocks are held for extremely brief durations, they can slow performance in multiprocessor systems with high transaction rates. If spinlock contention is more than 10%, consider using named caches or adding cache partitions.

See Chapter 5, “Memory Use and Performance,” in Performance and Tuning: Basics for information on adding caches.