From: Chen Jie <[email protected]>
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.
[[email protected]: rewrote changelog]
Acked-by: Michal Hocko <[email protected]>
Signed-off-by: Chen Jie <[email protected]>
Signed-off-by: David Rientjes <[email protected]>
---
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.
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;
On Wed 02-12-15 15:10:28, David Rientjes wrote:
> From: Chen Jie <[email protected]>
>
> 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.
>
> [[email protected]: rewrote changelog]
> Acked-by: Michal Hocko <[email protected]>
> Signed-off-by: Chen Jie <[email protected]>
> Signed-off-by: David Rientjes <[email protected]>
> ---
> 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
>
> From: Chen Jie <[email protected]>
>
> 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.
>
> [[email protected]: rewrote changelog]
> Acked-by: Michal Hocko <[email protected]>
> Signed-off-by: Chen Jie <[email protected]>
> Signed-off-by: David Rientjes <[email protected]>
> ---
Acked-by: Hillf Danton <[email protected]>
> 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.
>
> 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;
>
> --