MemoryInUse[] reports wrong numbers?
- To: mathgroup at yoda.physics.unc.edu
- Subject: MemoryInUse[] reports wrong numbers?
- From: David Harrison <harrison%faraday at yoda.physics.unc.edu>
- Date: Thu, 22 Apr 1993 09:11:52 -0400
We are running MMA 2.1 on an HP9000/750 (HP-UX 8.07). When a MMA session gets fairly large ( >~ 8 Megabytes or so), MemoryInUse[] gives results which are greatly different from those reported by either HP's Glance, top, or vmstat(1), all three of which agree that MemoryInUse[] is returning a number about a factor of 2 too small. Note that I am comparing the resident program size from Glance/top/vmstat to MemoryInUse[], not the total program size. Further, Glance/top/vmstat seem to be correct since the UNIX kernel begins paging when MMA has eaten all the RAM. As an undergraduate computing facility, we placed a governor on the size of a MMA session based on David Withoff's <withoff at wri.com> posted automatic invocation of Share for large kernels, supplemented by Todd Gayley's <tgayley at wri.com> extension invoking ClearInOut and CleanSlate if Share doesn't sufficiently reduce the size of the kernel, and further extended by me to Exit[1] if those don't do the job. We now limit to MemoryInUse[] of 8000000 (8 Megs) to get an effective limit of 16 Megs. Is this a generic bug or HP specific? Am I misinterpreting something and it isn't a bug at all? Finally, could it be related to Jesus Rivero's recent post to this group of problems with big packages under Windows? -- David Harrison | "We place no reliance on virgin Dept. of Physics, Univ. of Toronto | or pigeon, Inet: harrison at faraday.physics.utoronto.ca | Our method is science, or aim Tel: 416-978-2977 Fax: 416-978-5848 | is religion." Aleister Crowley