36e89f928c
a standard configuration similar to [NO_]ADAPTIVE_MUTEXES. This feature causes Giant to be included in the set of mutexes adaptively spun on. It appears to have a positive effect on performance on SMP across several workloads, including measurements of a 16% improvement on buildworld, and 30%+ improvement for MySQL using the supersmack benchmark with Giant over the network stack; a 6% improvement without Giant on the network stack (as a result of less giant contention).