Enabling Caches
You are advised to enable caches in an environment with sufficient memory to improve the performance of MPI tasks. Add -mca coll_ucg_max_rcache_size 1024 to the command line. This parameter can control the cache size in the communication domain. Caches in different communication domains are independent of each other. After the communication domain is destroyed, the caches are automatically destroyed.
Parent topic: Command Description and Example