BIB-VERSION:: CS-TR-v2.0 ID:: ncstrl.dartmouthcs//TR93-198 ENTRY:: January 20, 1995 ORGANIZATION:: Dartmouth College, Computer Science TITLE:: The Expected Lifetime of "Single-Address-Space" Operating Systems TYPE:: Technical Report (paper) REVISION:: 3 AUTHOR:: Kotz, David AUTHOR:: Crow, Preston NOTE:: The 'January' in DATE is an arbitrary placeholder. DATE:: January 1993 RETRIEVAL:: For a paper copy, email RETRIEVAL:: For a paper copy, write to Technical Report Librarian Department of Computer Science Dartmouth College 6211 Sudikoff Laboratory Hanover, NH 03755-3510 USA RETRIEVAL:: Compressed Postscript at http://www.cs.dartmouth.edu/reports/TR93-198.ps.Z ABSTRACT:: Trends toward shared-memory programming paradigms, large (64-bit) address spaces, and memory-mapped files have led some to propose the use of a single virtual-address space, shared by all processes and processors. Typical proposals require the single address space to contain all process-private data, shared data, and stored files. To simplify management of an address space where stale pointers make it difficult to re-use addresses, some have claimed that a 64-bit address space is sufficiently large that there is no need to ever re-use addresses. Unfortunately, there has been no data to either support or refute these claims, or to aid in the design of appropriate address-space management policies. In this paper, we present the results of extensive kernel-level tracing of the workstations in our department, and discuss the implications for single-address-space operating systems. We found that single-address-space systems will not outgrow the available address space, but only if reasonable space-allocation policies are used, and only if the system can adapt as larger address spaces become available. NOTE:: The on-line version is a revision of March 15, 1996. An earlier revised version appeared in SIGMETRICS '94. The original technical report is not available on-line. END:: ncstrl.dartmouthcs//TR93-198