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Path: sserve!newshost.anu.edu.au!harbinger.cc.monash.edu.au!bunyip.cc.uq.oz.au!munnari.oz.au!news.Hawaii.Edu!ames!agate!howland.reston.ans.net!swrinde!news.uh.edu!moocow.cs.uh.edu!wjin From: wjin@moocow.cs.uh.edu (Woody Jin) Newsgroups: comp.os.386bsd.bugs Subject: Re: Possible Swapping bug (or design flaw?) Date: 12 Jul 1994 17:13:58 GMT Organization: University of Houston Lines: 38 Message-ID: <2vuj0m$bhf@masala.cc.uh.edu> References: <5JUL199421385862@acad3.alaska.edu> <hk4RJ35.dysonj@delphi.com> NNTP-Posting-Host: moocow.cs.uh.edu In article <hk4RJ35.dysonj@delphi.com>, John Dyson <dysonj@delphi.com> wrote: >KIENENBERGER MIKE L <fxmlk@acad3.alaska.edu> writes: > >>The problem is that while a "ps aux" shows that the child process has exited >>and isn't using any memory, "/usr/sbin/swapinfo -k" shows that the virtual >>memory in use was never freed. Additional forks() will use additional virtual >>memory until the system finally freezes up when we run out of virtual memory. >>Terminating the original process (the parent of each child) finally releases >>the swap space allocated and the operating system returns to normal. > >to make this problem essentially go-away. The problem has to do with >VM objects being left around after a child process exits, etc. It is >a difficult problem to solve and the obvious solutions can be *very* >inefficient. We have modified the swap pager and written some missing >bits in the VM code and all but totally eliminated the problem. There >are still some possible second-order problems that we did not solve, but >they are very difficult to demonstrate. If any user *ever* demonstrates >the problem -- I will be very motivated to fix it (they would be using >the system *very* aggressively in *very* special circumstances.) I am not sure whether my problem can be used for the demonstation you want. My configuration is : 386/25 with 8M, running FreeBSD1.1.5. with XFree 2.11. The problem happens when I run Mosaic (non-shared). For sometime after I type 'Mosaic', I can hear disk drive grinding sound, then it becomes quite. The cursor disappears. I just can't do anything. I am patient. So, I wait. I can hear a very short duration of disk drive grinding sound once in a while, but system still looks freezed. The Mosaic screen appears after 10 min. After then the system behaves normal. It seems strange to me that it takes so long time, even though Mosaic's binary is huge. But anyway, my system is low-end and I am just happy that it works. I just always leave the Mosaic's window open. Woody Jin