# Re: \[PATCH -mm v9 6/8\] proc: add kpageidle file

- From: Vladimir Davydov \<hidden\>
- Date: 2015-07-24 14:17:53 
- List: linux-api
- Page: https://ratatoskr.run/linux-api/2015/07/4542485
- Thread: https://ratatoskr.run/linux-api/2015/07/4538187/t.md

```text
On Fri, Jul 24, 2015 at 10:08:25AM -0400, Paul Gortmaker wrote:

> fs/proc/page.c:341:4: error: implicit declaration of function
> 'pmdp_clear_young_notify' [-Werror=implicit-function-declaration]
> fs/proc/page.c:347:4: error: implicit declaration of function
> 'ptep_clear_young_notify' [-Werror=implicit-function-declaration]
> cc1: some warnings being treated as errors
> make[3]: *** [fs/proc/page.o] Error 1
> make[2]: *** [fs/proc] Error 2

My bad, sorry.

It's already been reported by the kbuild-test-robot, see

  [linux-next:master 3983/4215] fs/proc/page.c:332:4: error: implicit declaration of function 'pmdp_clear_young_notify'

The fix is:

From: Vladimir Davydov <redacted>
Subject: [PATCH] mmu_notifier: add missing stubs for clear_young

This is a compilation fix for !CONFIG_MMU_NOTIFIER.

Fixes: mmu-notifier-add-clear_young-callback
Signed-off-by: Vladimir Davydov <redacted>

diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index a5b17137c683..a1a210d59961 100644
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -471,6 +471,8 @@ static inline void mmu_notifier_mm_destroy(struct mm_struct *mm)
 
 #define ptep_clear_flush_young_notify ptep_clear_flush_young
 #define pmdp_clear_flush_young_notify pmdp_clear_flush_young
+#define ptep_clear_young_notify ptep_test_and_clear_young
+#define pmdp_clear_young_notify pmdp_test_and_clear_young
 #define	ptep_clear_flush_notify ptep_clear_flush
 #define pmdp_huge_clear_flush_notify pmdp_huge_clear_flush
 #define pmdp_huge_get_and_clear_notify pmdp_huge_get_and_clear
```