My kernel version is 3.10 ,but the 4.3 is the same
and the newest code is

        for_each_process(p) {
                if (!process_shares_mm(p, mm))
                        continue;
                if (same_thread_group(p, victim))
                        continue;
                if (unlikely(p->flags & PF_KTHREAD))
                        continue;
                if (p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
                        continue;

so this not add the !is_global_init also.

when we vfork (CLONE_VM) a process,the copy_mm
        if (clone_flags & CLONE_VM) {
                atomic_inc(&oldmm->mm_users);
                mm = oldmm;
                goto good_mm;
        }
use the parent mm.




On 2015/11/30 11:08, Andrew Morton wrote:
On Mon, 30 Nov 2015 18:54:29 +0800 <chenj...@huawei.com> wrote:

From: chenjie <chenj...@huawei.com>

when oom happened we can see:
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

That's because:
        the busybox init will vfork a process,oom_kill_process found
the init not the children,their mm is the same when vfork.

...

--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -513,7 +513,7 @@ void oom_kill_process(struct task_struct *p, gfp_t 
gfp_mask, int order,
        rcu_read_lock();
        for_each_process(p)
                if (p->mm == mm && !same_thread_group(p, victim) &&
-                   !(p->flags & PF_KTHREAD)) {
+                   !(p->flags & PF_KTHREAD) && !is_global_init(p)) {
                        if (p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
                                continue;

What kernel version are you using?

I don't think this can happen in current code...

.


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