[RFC 1/2] mm: oom: expose expedite_reclaim to use oom_reaper outside of oom_kill.c

Suren Baghdasaryan
2019-04-11T01:44:07Z

Create an API to allow users outside of oom_kill.c to mark a victim and
wake up oom_reaper thread for expedited memory reclaim of the process being
killed.

Signed-off-by: Suren Baghdasaryan <surenb@google.com>
---
include/linux/oom.h | 1 +
mm/oom_kill.c | 15 +++++++++++++++
2 files changed, 16 insertions(+)

diff --git a/include/linux/oom.h b/include/linux/oom.h
index d07992009265..6c043c7518c1 100644
--- a/include/linux/oom.h
+++ b/include/linux/oom.h
@@ -112,6 +112,7 @@ extern unsigned long oom_badness(struct task_struct *p,
unsigned long totalpages);

extern bool out_of_memory(struct oom_control *oc);
+extern bool expedite_reclaim(struct task_struct *task);

extern void exit_oom_victim(void);

diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 3a2484884cfd..6449710c8a06 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -1102,6 +1102,21 @@ bool out_of_memory(struct oom_control *oc)
return !!oc->chosen;
}

+bool expedite_reclaim(struct task_struct *task)
+{
+ bool res = false;
+
+ task_lock(task);
+ if (task_will_free_mem(task)) {
+ mark_oom_victim(task);
+ wake_oom_reaper(task);
+ res = true;
+ }
+ task_unlock(task);
+
+ return res;
+}
+
/*
* The pagefault handler calls here because it is out of memory, so kill a
* memory-hogging task. If oom_lock is held by somebody else, a parallel oom
--
2.21.0.392.gf8f6787159e-goog