Physical Sciences and Mathematics Commons^™

Scalable Approaches For Supporting Mpi-Io Atomicity, Peter Aarestad, George K. Thiruvathukal, Avery Ching, Alok Choudhary

Computer Science: Faculty Publications and Other Works

Scalable atomic and parallel access to noncontiguous regions of a file is essential to exploit high performance I/O as required by large-scale applications. Parallel I/O frameworks such as MPI I/O conceptually allow I/O to be defined on regions of a file using derived datatypes. Access to regions of a file can be automatically computed on a perprocessor basis using the datatype, resulting in a list of (offset, length) pairs. We describe three approaches for implementing lock serving (whole file, region locking, and byterange locking) and compare the various approaches using three noncontiguous I/O benchmarks. We present the details of the …