Using unix without the pretty OS...

Hi Mike,
It doesn't work consistently on Tiger but you can try logging in with the following username:

console

Don't put anything in the password field.

512MB is cramped but doable for most purposes. If this is the only problem you're having then it may not be worth it to get more RAM but it usually helps to get more.

It's also possible that you're running into a limit on the number of processes. It's easy to fork processes in Perl and while parallel processing helps up to a point, I've seen many scripters go overboard. Most of the scripts crash when a fork fails but maybe this one handles the error and keeps trying to spawn new ones. That could also cause a noticeable slowdown. While the script is running you could run "ps -auxww" and see if you have more than a hundred processes.
--
Gary
~~~~
Food for thought is no substitute for the real thing.
-- Walt Kelly, "Potluck Pogo"

i.e. I ran a memory hungry process and it choked at the same point that it choked when I was running the script with the regular aqua business running.

*nix boxes don't choke when they have too little memory, they slow to a crawl because they're swapping and in extreme cases thrashing. If the box is swapping, it would be swapping to the swap files in /var/vm. These appear to be regular files, so if you do:

ls -l /var/vm

you should see mod times on them.

You may also want to try running (in another terminal window):

top -o cpu

while you run these perl scripts to see where resources are going.

Roger

Before you do that, you should probably take a look at the kernel parameters. Apple has some "interesting" settings that quite probably need to be changed for the stuff that you're doing.

sysctl -a | more

Roger

ulimit -d

the value may not be set high enough. on my system it's defaulting to
around 6144KB.

try bumping it up some.

ulimit -d <value>

check the manpage for the shell that you're using to find out more.

Andy

The ulimit limits are manipulated through the shell. The sysctl parameters can be manipulated through the sysctl command, and made persistent by putting them in /etc/sysctl.conf (which will need to be created). Some kernel parameters (usally of the on/off type) can be changed on a running machine, others require a restart.

On my XServe, I've found that the /etc/rc scripts sets some values after /etc/sysctl.conf is processed, so you may want to move those parameters into /etc/sysctl.conf and comment out the lines in /etc/rc.

The sysctl man page will explain the syntax involved for both the command line and sysctl.conf.

From Nils' post, it sounds more like ulimit, especially is you're running this stuff as an unprivledged user may be a better first choice. Kernel tuning isn't really for the faint of heart.

/etc/bashrc will make any ulimit changes persist.

Roger

This is strange, you shouldn't get a seg fault, you should just get a NULL from malloc.

Does your memory have to be contiguous? Can you malloc a bunch of lines using a linked list?

he might get a segfault, if malloc returns a null. if the app doesn't check the return value.

Yeah, my point exactly, it is a poorly programmed app.

oh. sorry.