Re: lug-bg: Elegantly wasting system resources (Was: problem)

[danchev@xxxxxxxxx (George Danchev)]

On Sunday 16 December 2001 10:43, you wrote:
> Vizh komandata ulimit i file-a /etc/security/limits.conf Povecheto sistemi
> po default sa taka natroeni, che shte zaspqt neprobudno pri izpylnenie na
> programa ot sorta:
>
> int main()
> {
>   fork();
>   main();
> }
>
> Ako si ogranichil obache maksimalniq broj procesi na user-a s podoben red
> v /etc/security/limits.conf
>
> haralampi            hard    nproc            64
>
> to mashinata shte ostane na kraka. Analogichno mozhesh da regulirash
> maksimalnata golemina na stack-a, pametta za proces, procesorno vreme,
> otvoreni file-ove...
>
> Petko
mda maj tova me interesuvashe. pak nesto ne sym dopro4el.
No vse pak mi se struva 4e haralampi mozhe da se izmukne i da tormozi 
sistemata postoqnno v ramkite na dopystimoto....
da kazhem VM s nesto ot sorta:
---allocate.c---------
#include <stdlib.h>
main()
{
    /* allocate about 20 megs, ili tam kolkoto */
    /* trqbva za da se vmesti v ograni4eniqta  */

    void *ptr = (void *)calloc(5000000, sizeof(int)); 
    
    /* naro4no ne q  osvobozhdava => load (losho)     */
    /* namesva se OOM killer-a i pokraj tozi proces     */
    /* mozhe da killne i nqkoj vazhen proces    */
    /* kojto haralampi nqma prava da kill           */ 
    /*   ste se radva da vidi:               */
    /* VM: killing process "us"                 */
    /* VM: killing process bash                 */
    /* VM: killing process apache               */
    /*      and so on ...  *grinz*           */
                                             
    /* free(ptr);                               */
}
-------------------------

led koeto q startira gurbo, kernel-a ste se bori s zubi i nokti za da zapazi 
machinata *up*. Spravq se, no tyrpi tormoz, da kezhem v ramkite na 
dopystimoto.... a tova mozhe da se slu4va permanentno. damn.

----avalanche.sh----------    
#!/bin/bash
z=0;
while [ $z != 1 ] ; do
./allocate &
done
-------------------------------

ili po-kulturno, ve4e kontroliruemo. Ako trea ste opredeli MemFree+SwapFree i 
ste se opita da shruska kolkoto mozhe ot tqh.

------avalanche2.sh----------------------
# naprimer: 3/4 of RAM+SWAP sa Free, startirajki
# allocate (zaemasta po 20 megs/time) N pyti 
# N = 3/4 * (RAM+SWAP)/20 ve4e ne sa free.
z=0;
while [ $z != 1 ] ; do
#   running "allocate" N times.
    for i in 1 2 3 4 5 6 7 8 9 10 11 12 ; do
    ./allocate &
done
done
---------------------------

Sled tova ste se seti da pridizvika severe disk I/O activity ... i t.n. 
Ste my setna quotas, i gornite ograni4eniq, ama vinagi mozhe da si dovle4e 
source ili binaries v home dir-a i da si pravi experimenti.

10x, kakto i da e ... ste pomislq za limits.conf.

-- 
Greets, 
fr33zb1
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