[patch] oom: thaw threads if oom killed thread is frozen before deferring

David Rientjes
2011-09-27T18:35:14Z

On Tue, 27 Sep 2011, Michal Hocko wrote:

> diff --git a/mm/oom_kill.c b/mm/oom_kill.c
> index 626303b..c419a7e 100644
> --- a/mm/oom_kill.c
> +++ b/mm/oom_kill.c
> @@ -32,6 +32,7 @@
> #include <linux/mempolicy.h>
> #include <linux/security.h>
> #include <linux/ptrace.h>
> +#include <linux/freezer.h>
>
> int sysctl_panic_on_oom;
> int sysctl_oom_kill_allocating_task;
> @@ -451,10 +452,15 @@ static int oom_kill_task(struct task_struct *p, struct mem_cgroup *mem)
> task_pid_nr(q), q->comm);
> task_unlock(q);
> force_sig(SIGKILL, q);
> +
> + if (frozen(q))
> + thaw_process(q);
> }
>
> set_tsk_thread_flag(p, TIF_MEMDIE);
> force_sig(SIGKILL, p);
> + if (frozen(p))
> + thaw_process(p);
>
> return 0;
> }

Also needs this...

oom: thaw threads if oom killed thread is frozen before deferring

If a thread has been oom killed and is frozen, thaw it before returning
to the page allocator. Otherwise, it can stay frozen indefinitely and
no memory will be freed.

Signed-off-by: David Rientjes <rientjes@google.com>
---
mm/oom_kill.c | 5 ++++-
1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/mm/oom_kill.c b/mm/oom_kill.c
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -318,8 +318,11 @@ static struct task_struct *select_bad_process(unsigned int *ppoints,
* blocked waiting for another task which itself is waiting
* for memory. Is there a better alternative?
*/
- if (test_tsk_thread_flag(p, TIF_MEMDIE))
+ if (test_tsk_thread_flag(p, TIF_MEMDIE)) {
+ if (unlikely(frozen(p)))
+ thaw_process(p);
return ERR_PTR(-1UL);
+ }
if (!p->mm)
continue;