On Fri, Nov 09, 2001 at 04:55:52PM -0800, rpc wrote: > On Wed, 1 Jan 1997, Ralf Dreibrodt wrote: > > Hi, > > >while running "vi `perl -e 'print "." x 90000000'`" on > > >a 2.2.20 linux kernel as a normal user, I've noticed: > > >forsaken:~$ dmesg > > >VM: killing process snmpd > > >forsaken:~$ uname -rs > > >Linux 2.2.20 > > >snmpd was running as root (this machine has 64MBytes of RAM) > > the user is not allowed to kill a process owned by root, the user is allowed > > to use all RAM (and probably swap). > > > > you can test whether he is allowed to and what will happen, when you execute > > something like this: > > > > while true; do temp=$(echo temp$temp$temp$temp); done > > No, this is an artifact of Rik van Riel's OOM (out of memory) Kill code of > the linux VM. When system resources are low, a process is chosen with a > 'badness' algorithm (oom_kill.c in the kernel source tree). it always a good idea to set system limit per users (ulimit) which lets you to avoid DOS from local user: for example there was this beautifoul piece of code on to an attachment of a guy ... :(){:|:&};: which cause to gain all system resources and freeze your machine ... . with ulimit you can avoid problems depended from ppl trying to catch all system resources and so avoid that problem you specify. Samuele -- Samuele Tonon <samuat_private> http://www.linuxasylum.net/~samu/ Acid -- better living through chemistry. Timothy Leary
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