Summary: Anonymous RPC:
Low­Latency Protection in a 64­Bit Address Space
Curtis Yarvin, Richard Bukowski, and Thomas Anderson
Computer Science Division
University of California at Berkeley
Abstract
In this paper, we propose a method of reducing the latency of cross­domain remote procedure
call (RPC). Traditional systems use separate address spaces to provide memory protection
between separate processes, but even with a highly optimized RPC system, the cost of switching
between address spaces can make cross­domain RPC's prohibitively expensive.
Our approach is to use anonymity instead of hardware page tables for protection. Logically
independent memory segments are placed at random locations in the same address space and
protection domain. With 64­bit virtual addresses, it is unlikely that a process will be able to
locate any other segment by accidental or malicious memory probes; it impossible to corrupt
a segment without knowing its location. The benefit is that a cross­domain RPC need not
involve a hardware context switch. Measurements of our prototype implementation show that
a round­trip null RPC takes only 7.7¯s on an Intel 486­33.
1 Introduction
A traditional function of operating systems is providing protection domains, or areas of memory
accessible only by the process which owns them. UNIX, for example, keeps every process in an entirely

Source: Anderson, Tom - Department of Computer Science and Engineering, University of Washington at Seattle

Collections: Computer Technologies and Information Sciences