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-rw-r--r--mm/oom_kill.c40
1 files changed, 25 insertions, 15 deletions
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index d7f345e47e73..33b58615072c 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -31,6 +31,7 @@
#include <linux/memcontrol.h>
#include <linux/mempolicy.h>
#include <linux/security.h>
+#include <linux/ptrace.h>
int sysctl_panic_on_oom;
int sysctl_oom_kill_allocating_task;
@@ -316,22 +317,29 @@ static struct task_struct *select_bad_process(unsigned int *ppoints,
if (test_tsk_thread_flag(p, TIF_MEMDIE))
return ERR_PTR(-1UL);
- /*
- * This is in the process of releasing memory so wait for it
- * to finish before killing some other task by mistake.
- *
- * However, if p is the current task, we allow the 'kill' to
- * go ahead if it is exiting: this will simply set TIF_MEMDIE,
- * which will allow it to gain access to memory reserves in
- * the process of exiting and releasing its resources.
- * Otherwise we could get an easy OOM deadlock.
- */
if (p->flags & PF_EXITING) {
- if (p != current)
- return ERR_PTR(-1UL);
-
- chosen = p;
- *ppoints = 1000;
+ /*
+ * If p is the current task and is in the process of
+ * releasing memory, we allow the "kill" to set
+ * TIF_MEMDIE, which will allow it to gain access to
+ * memory reserves. Otherwise, it may stall forever.
+ *
+ * The loop isn't broken here, however, in case other
+ * threads are found to have already been oom killed.
+ */
+ if (p == current) {
+ chosen = p;
+ *ppoints = 1000;
+ } else {
+ /*
+ * If this task is not being ptraced on exit,
+ * then wait for it to finish before killing
+ * some other task unnecessarily.
+ */
+ if (!(task_ptrace(p->group_leader) &
+ PT_TRACE_EXIT))
+ return ERR_PTR(-1UL);
+ }
}
points = oom_badness(p, mem, nodemask, totalpages);
@@ -493,6 +501,8 @@ static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
list_for_each_entry(child, &t->children, sibling) {
unsigned int child_points;
+ if (child->mm == p->mm)
+ continue;
/*
* oom_badness() returns 0 if the thread is unkillable
*/