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- Newsgroups: comp.sys.sun.misc
- Path: sparky!uunet!island!coney!hue
- From: hue@island.COM (Pond Scum)
- Subject: Re: System Mode Swamp on Sparc 2
- Message-ID: <hue.726709501@coney>
- Sender: usenet@island.COM (The Usenet mail target)
- Organization: Island Graphics Corp.
- References: <FMRCO!MSOMMER.93Jan7093547@ampere.uunet.uu.net>
- Distribution: usa
- Date: Sun, 10 Jan 1993 23:45:01 GMT
- Lines: 21
-
- fmrco!msommer@uunet.uu.net (Mark Sommer) writes:
- >My program calls a Fortran function to solve a large quadratic
- >programming problem. The program is extremely computationally
- >intensive and it runs very large (>10MB), but my machine has 48MB of
- >memory and lots of swap space (>80MB), so I would have expected it to
- >spend most of its time in user mode. In fact, according to many
- >indicators (such as gprof), it spends most of its time in kernel mode.
-
- Warning: I really have no idea what's going on here, this is just a guess,
- plus I have a bad memory.
-
- Could it be that your program is generating a lot of exceptions
- (floating point exceptions) and is having to drop into the kernel to
- handle these exceptions?
-
- Another possibility is that your program was compiled to use some
- sort of floating point coprocessor, and it's not present so you're
- trapping on every operation and the kernel is emulating it. I think
- this used to happen on Sun-4/110s.
-
- -Jonathan hue@island.COM
-