Massively parallel computers are increasingly being used to solve large, I/O intensive applications in many different fields. For such applications, the I/O requirements quite often present a significant obstacle in the way of achieving good performance, and an important area of current research is the development of techniques by which these costs can be reduced. One such approach is collective I/O, where the processors cooperatively develop an I/O strategy that reduces the number, and increases the size, of I/O requests, making a much better use of the I/O subsystem. Collective I/O has been shown to significantly reduce the cost of performing I/O in many large, parallel applications, and for this reason serves as an important base upon which we can explore other mechanisms which can further reduce these costs. One promising approach is to use threads to perform the collective I/O in the background while the main thread continues with other computation in the foreground. In this pape...
Phillip M. Dickens, Rajeev Thakur