On 05/31, Michal Hocko wrote: > > On Mon 30-05-16 20:18:16, Oleg Nesterov wrote: > > > > perhaps the is_global_init() == T case needs a warning too? the previous changes > > take care about vfork() from /sbin/init, so the only reason we can see it true > > is that /sbin/init shares the memory with a memory hog... Nevermind, forget. > > I have another two patches waiting for this to settle and one of them > adds a warning to that path. Good, > > This is a bit off-topic, but perhaps we can also change the PF_KTHREAD check later. > > Of course we should not try to kill this kthread, but can_oom_reap can be true in > > this case. A kernel thread which does use_mm() should handle the errors correctly > > if (say) get_user() fails because we unmap the memory. > > I was worried that the kernel thread would see a zero page so this could > lead to a data corruption. We can't avoid this anyway. use_mm(victim->mm) can be called after we decide to kill the victim. So I think that we should always ignore kthreads, and in task_will_free_mem() too. But let me repeat, I agree we should discuss this later, I am not trying to suggest this change right now. Oleg. -- 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>