Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!samsung!uunet!mcsun!hp4nl!orcenl!hbergh From: hbergh@oracle.nl (Herbert van den Bergh) Newsgroups: comp.unix.aix Subject: Re: '6000 performance issue Message-ID: <1131@nlsun1.oracle.nl> Date: 20 Nov 90 12:55:00 GMT References: <1990Nov19.042905.26880@i88.isc.com> Reply-To: hbergh@oracle.nl (Herbert van den Bergh) Organization: Oracle Europe, The Netherlands Lines: 25 In article marc@arnor.uucp writes: >Of course, each process has its own copy of any data pages it has >touched. Can you tell me if this is also the case when a process only reads a data page from a shared library? Is it not copied on write? And what happens to data pages from an executable file? If they are only referenced for reading, does each process still get its own copy? We're trying some time now to figure out how efficient AIX memory usage is related to our applications. When running a client-server application, each client forks and executes a process that communicates with the server. This process currently has a data segment of 180Kb, of which about 100Kb is never modified. You can imagine what performance improvement sharing this data could give. We haven't found a way to figure out exactly how much memory is in use by a certain process (virual and real) and by all processes together in the system. The getrusage() routine doesn't seem to tell the truth, and we're not sure about ps. -- Herbert van den Bergh, Email: hbergh@oracle.nl, hbergh@oracle.com ORACLE Europe