Yesterday i make a test like this in a virtual console not as root(X is not running).
I started the program and after a few seconds it began to give the message below. ./test: fork: try again then i changed th virtual console and try pressing Ctrl-Alt-Del but the system didn't respond. The after 10 minutes i pressed the reset button. i think too that there must be a way to restrict the processes to call them recursively in a limit. ---------- Forwarded message ---------- Date: Thu, 05 Dec 1996 20:06:57 +0100 From: [EMAIL PROTECTED] To: "ken (k.y.) chan" <[EMAIL PROTECTED]> Cc: debian-user@lists.debian.org Subject: Re: A newbie recursion problem...:-)))) Resent-Date: Thu, 5 Dec 1996 22:06:11 +0300 Resent-From: debian-user@lists.debian.org ken (k.y.) chan wrote: > > In message "A newbie recursion problem...:-))))", > '[EMAIL PROTECTED]' writes: > > >Hi to all, > > > >well I do not know whether this is a bug or not... > >Suppose a user would create a file with say ten lines, each line > >containig just the word test. Then s/he will save it as test and s/he > >will make it executable. Now s/he will open say 4 xterminals and in each > >he will just type test & (followed by enter). On my Debian this will > >cause the system to nearly "stop" and the load of the system will never > >end... > > In fact, if you have 10 lines of "test &" in each test file instead, > you would be creating new process at a rate of 4*10 process per > *cycle* :). > > Also, you don't need to have ten lines of "test" in your executable > called test. All you need is one line of "test", then you will have > an infinite execution recursion if you are running it under the > same directory..etc, at a rate of 4 new processes per *execution* :) > > >I remember that when this user types test & in each line of the file the > >system will slow down too and I think it never stops swapping... > >The system did not crash but was no more usable untill killing of X. > >Well I'm a newbie, but someone knows, whether there is a cure to this??? > >I think that the kernel should prevent this recursion...any > >propositions??? Solutions are welcome.... > > > If you are not running as a root, then you should be restricted to > a limited of number of processes that you can have at any time (I > forgot where it is defined). Linux should always reserve one process > *space* in the system so that if you have too many processes running, > you can still > spawn a KILL process to kill them all. If not, I consider that > a bug in the kernel. I was running as a user not root, and I think that I was not restricted to a limited number of processes, well in a way... I only got the error Message: ./test: fork: Try again This message "never" stopped and the system slowed down every second... The only way for me to stop all this was to close the xterminal...the time I could move the pointer...or later only by killing X with <Ctrl-Alt-F1> I suppose that this IS a bug, because I know, that e.g. on a sparc or dec or HP a recursion like this is just killed by the OS. My system has 40MB of RAM and finally I had just 400KB of free memory, only after running this little recursion...:-))) BTW I'm running the 2.0.25 kernel. Oh...where can I define the max number of processes for a user??? Greetings Andreas -- TO UNSUBSCRIBE FROM THIS MAILING LIST: e-mail the word "unsubscribe" to [EMAIL PROTECTED] . Trouble? e-mail to [EMAIL PROTECTED] -- TO UNSUBSCRIBE FROM THIS MAILING LIST: e-mail the word "unsubscribe" to [EMAIL PROTECTED] . Trouble? e-mail to [EMAIL PROTECTED]
