On mercoledì 9 maggio 2007, [EMAIL PROTECTED] wrote:
> Hi all,
>
> I tryed to drop a forkbomb into a uml.
> The host system is a Debian testing(lenny) with a vanilla kernel 2.6.20,
> the latest skas patch for that kernel and sarge guest fs with 2.6.18
> shipped with debian stable(etch).
>
> As far as I could try I launched 3 uml's I logd via ssh to root and :(){
> :|:&};:
:(){ :|:&};:
> after some times( between 20 and 40 seconds of forks errorAhah! Forks errors. Only the one below or other ones? I expect you to get EAGAIN, because there is too little free memory to start all those processes. Normally a forkbomb exhausts CPU faster than memory (because there is also swap configured). With 32M or 64M of RAM and swap disabled, I get multiple OOM. Have you enabled swap for your UML? The more you give it, the more it will thrash. > I've see the > forks procesess terminating and the terminal of that guest up again, > I have no limits setted on the host nor into the uml, maybe someone have > an explanation :). > For who can be interested this is tail -f /var/log/kern.log of the guest, > nothing on the host: > > May 9 09:50:35 vm01 kernel: BUG: warning at > kernel/rtmutex-debug.c:126/rt_mutex_debug_task_free() > May 9 09:50:35 vm01 kernel: 0b997b6c: [<0806cdbc>] dump_stack+0x4c/0x5e > May 9 09:50:35 vm01 kernel: 0b997b84: [<080fd242>] > rt_mutex_debug_task_free+0xaa/0x124 > May 9 09:50:35 vm01 kernel: 0b997ba0: [<080b3771>] free_task+0x36/0x66 > May 9 09:50:35 vm01 kernel: 0b997bb4: [<080b847b>] > copy_process+0x2a06/0x2a54 > May 9 09:50:35 vm01 kernel: 0b997be0: [<080b87bb>] do_fork+0x1eb/0x52f > May 9 09:50:35 vm01 kernel: 0b997c3c: [<080ab285>] sys_clone+0xca/0x108 > May 9 09:50:35 vm01 kernel: 0b997c64: [<080713a3>] > handle_syscall+0xd7/0x10e > May 9 09:50:35 vm01 kernel: 0b997cb4: [<080a5b74>] userspace+0x446/0x557 > May 9 09:50:35 vm01 kernel: 0b997cfc: [<08070cee>] > fork_handler+0x1ec/0x202 May 9 09:50:35 vm01 kernel: 0b997d1c: > [<08470098>] __restore+0x0/0x8 > > Is this some real bug or just as result of the forkbomb? This is a warning I haven't had the time to investigate over. -- Inform me of my mistakes, so I can add them to my list! Paolo Giarrusso, aka Blaisorblade http://www.user-mode-linux.org/~blaisorblade ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ User-mode-linux-user mailing list User-mode-linux-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user
