mm: oom_reaper: remove some bloat

mmput_async is currently used only from the oom_reaper which is defined only for CONFIG_MMU. We can save work_struct in mm_struct for !CONFIG_MMU. [[email protected]: fix typo, per Minchan] Link: http://lkml.kernel.org/r/[email protected] Reported-by: Minchan Kim <[email protected]> Signed-off-by: Michal Hocko <[email protected]> Acked-by: Minchan Kim <[email protected]> Cc: Tetsuo Handa <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
ambv · May 26, 2016 · 7ef949d · 7ef949d
1 parent 1ebab2d
commit 7ef949d
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Showing 3 changed files with 7 additions and 1 deletion.
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
@@ -514,7 +514,9 @@ struct mm_struct {
 #ifdef CONFIG_HUGETLB_PAGE
 	atomic_long_t hugetlb_usage;
 #endif
+#ifdef CONFIG_MMU
 	struct work_struct async_put_work;
+#endif
 };
 
 static inline void mm_init_cpumask(struct mm_struct *mm)

diff --git a/include/linux/sched.h b/include/linux/sched.h
@@ -2745,10 +2745,12 @@ static inline bool mmget_not_zero(struct mm_struct *mm)
 
 /* mmput gets rid of the mappings and all user-space */
 extern void mmput(struct mm_struct *);
-/* same as above but performs the slow path from the async kontext. Can
+#ifdef CONFIG_MMU
+/* same as above but performs the slow path from the async context. Can
  * be called from the atomic context as well
  */
 extern void mmput_async(struct mm_struct *);
+#endif
 
 /* Grab a reference to a task's mm, if it is not already going away */
 extern struct mm_struct *get_task_mm(struct task_struct *task);

diff --git a/kernel/fork.c b/kernel/fork.c
@@ -736,6 +736,7 @@ void mmput(struct mm_struct *mm)
 }
 EXPORT_SYMBOL_GPL(mmput);
 
+#ifdef CONFIG_MMU
 static void mmput_async_fn(struct work_struct *work)
 {
 	struct mm_struct *mm = container_of(work, struct mm_struct, async_put_work);
@@ -749,6 +750,7 @@ void mmput_async(struct mm_struct *mm)
 		schedule_work(&mm->async_put_work);
 	}
 }
+#endif
 
 /**
  * set_mm_exe_file - change a reference to the mm's executable file