On Tue, Mar 22, 2011 at 8:08 PM, KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> wrote: > When plenty processes (eg fork bomb) are running, the TIF_MEMDIE task > never exit, at least, human feel it's never. therefore kernel become > hang-up. > > "perf sched" tell us a hint. > > Â------------------------------------------------------------------------------ > ÂTask         Â|  Runtime ms Â| Average delay ms | Maximum delay ms | > Â------------------------------------------------------------------------------ > Âpython:1754      |   Â0.197 ms | avg: 1731.727 ms | max: 3433.805 ms | > Âpython:1843      |   Â0.489 ms | avg: 1707.433 ms | max: 3622.955 ms | > Âpython:1715      |   Â0.220 ms | avg: 1707.125 ms | max: 3623.246 ms | > Âpython:1818      |   Â2.127 ms | avg: 1527.331 ms | max: 3622.553 ms | > Â... > Â... > > Processes flood makes crazy scheduler delay. and then the victim process > can't run enough. Grr. Should we do? > > Fortunately, we already have anti process flood framework, autogroup! > This patch reuse this framework and avoid kernel live lock. That's cool idea but I have a concern. You remove boosting priority in [2/5] and move victim tasks into autogroup. If I understand autogroup right, victim process and threads in the process take less schedule chance than now. Could it make unnecessary killing of other tasks? I am not sure. Just out of curiosity. Thanks for nice work, Kosaki. -- Kind regards, Minchan Kim -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href