Abstract: Technical solutions are described for executing a plurality of computer-executable synchronous input/output (I/O) commands received by a storage control unit in a multiple virtual storage system. An example method includes receiving a set of synchronous I/O commands, each of the commands received from a respective operating system from a plurality of operating systems. The method further includes selecting, from the set of synchronous I/O operations, a subset of synchronous I/O commands, and allocating a shared resource to the subset of synchronous I/O commands. The method further includes executing each synchronous I/O command from the selected subset of synchronous I/O commands concurrently.

Abstract: A method may involve assigning each of a plurality of freelists and a plurality of hashlists used to implement a cache to one of a plurality of lock groups and acquiring one of a plurality of locks. Objects on each freelist and hashlist that are assigned to the same lock group are allocated from the same one of a plurality of memory allocation pools. Each lock group is associated with a respective one of the plurality of locks. Acquiring the lock locks a freelist and several hashlists included in an associated lock group of the plurality of lock groups.