On Wed 02-12-15 15:10:28, David Rientjes wrote: > From: Chen Jie <chenjie6@xxxxxxxxxx> > > It's possible that an oom killed victim shares an ->mm with the init > process and thus oom_kill_process() would end up trying to kill init as > well. > > This has been shown in practice: > > Out of memory: Kill process 9134 (init) score 3 or sacrifice child > Killed process 9134 (init) total-vm:1868kB, anon-rss:84kB, file-rss:572kB > Kill process 1 (init) sharing same memory > ... > Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009 > > And this will result in a kernel panic. > > If a process is forked by init and selected for oom kill while still > sharing init_mm, then it's likely this system is in a recoverable state. > However, it's better not to try to kill init and allow the machine to > panic due to unkillable processes. > > [rientjes@xxxxxxxxxx: rewrote changelog] > Acked-by: Michal Hocko <mhocko@xxxxxxxx> > Signed-off-by: Chen Jie <chenjie6@xxxxxxxxxx> > Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx> > --- > I removed stable from this patch since the alternative would most likely > be to panic the system for no killable processes anyway. There's a very > small likelihood this patch would allow for a recoverable system. Agreed. > mm/oom_kill.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/mm/oom_kill.c b/mm/oom_kill.c > --- a/mm/oom_kill.c > +++ b/mm/oom_kill.c > @@ -608,6 +608,8 @@ void oom_kill_process(struct oom_control *oc, struct task_struct *p, > continue; > if (unlikely(p->flags & PF_KTHREAD)) > continue; > + if (!is_global_init(p)) > + continue; > if (p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) > continue; > -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>