sched: mmdrop needs to be delayed on -rt

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

2 files changed, 11 insertions, 0 deletions

diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 7acc8439d9b3..bd799364147a 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -247,6 +247,9 @@ struct mm_struct {
         /* Architecture-specific MM context */
         mm_context_t context;
 
+        /* realtime bits */
+        struct list_head        delayed_drop;
+
         /* Swap token stuff */
         /*
          * Last value of global fault stamp as seen by this process.
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 2e5be662deef..ba941e448176 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2111,12 +2111,20 @@ extern struct mm_struct * mm_alloc(void);
 
 /* mmdrop drops the mm and the page tables */
 extern void __mmdrop(struct mm_struct *);
+extern void __mmdrop_delayed(struct mm_struct *);
+
 static inline void mmdrop(struct mm_struct * mm)
 {
         if (unlikely(atomic_dec_and_test(&mm->mm_count)))
                 __mmdrop(mm);
 }
 
+static inline void mmdrop_delayed(struct mm_struct * mm)
+{
+        if (atomic_dec_and_test(&mm->mm_count))
+                __mmdrop_delayed(mm);
+}
+
 /* mmput gets rid of the mappings and all user-space */
 extern void mmput(struct mm_struct *);
 /* Grab a reference to a task's mm, if it is not already going away */