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pC++ processes are BIG!
- Date: Sat, 18 Feb 1995 14:47:42 -0500
- From: "Vladimir Menkov" <vmenkov@cs.indiana.edu>
- To: sage-bugs@cica.indiana.edu
- Subject: pC++ processes are BIG!
(I tried to send this message a couple days ago, but am not
sure if it got through then with all the rainier problems).
Hello,
I wonder why pC++ programs take _so_ much space when run on SGI
machines. I took the simple.pc program from
TestSuite/Simple/simple.pc, inserted a busy wait loop
somewhere into it
double x = 1, y;
for(i=0; i<1000000; i++) {
y = x*2;
x = y/1.999999;
}
so that I would have some time to observe the program's behavior,
and compiled it for sgimp (sgi4k architecture), and ran it on ireland,
with the option -pcxx_PROCNUM 1. (After all, there is only 1 processor
on ireland).
"top" (the SGI program for monitoring the machine load) showed the
following statistics:
IRIX ireland 5.2 02282014 IP17 Load[0.18,0.05,0.01] 17:46:17 86 procs
user pid pgrp %cpu proc pri size rss time command
vmenkov 17383 17383 147.65 * 94 33093 66 0:12 sgimp
vmenkov 17033 17033 1.02 0 60 388 100 0:18 top
....
Acccording to the manual for "top", "size" here is "process size (in
pages)". I was told that a page is 4 kbytes, but I am not sure (I did
not call getpagesize(), after all).
Anyhow, 120 Megabytes seems a tad too much for a program that,
essentially, prints "Hello world!". Any guesses about where memory
goes, and what can be done to reduce the process size?
programs compiled for uniproc don't request particularly lareg amounts
of memory, BTW.
--Vladimir