From: Grygorii Strashko <Grygorii.Strashko@linaro.org>
Date: Tue, 21 Jul 2015 19:43:56 +0300
Subject: [PATCH 132/353] pid.h: include atomic.h
Origin: https://git.kernel.org/cgit/linux/kernel/git/rt/linux-stable-rt.git/commit?id=d5cd905ca7ce7ab06694717b22dd20b102a4ad36

This patch fixes build error:
  CC      kernel/pid_namespace.o
In file included from kernel/pid_namespace.c:11:0:
include/linux/pid.h: In function 'get_pid':
include/linux/pid.h:78:3: error: implicit declaration of function 'atomic_inc' [-Werror=implicit-function-declaration]
   atomic_inc(&pid->count);
   ^
which happens when
 CONFIG_PROVE_LOCKING=n
 CONFIG_DEBUG_SPINLOCK=n
 CONFIG_DEBUG_MUTEXES=n
 CONFIG_DEBUG_LOCK_ALLOC=n
 CONFIG_PID_NS=y

Vanilla gets this via spinlock.h.

Signed-off-by: Grygorii Strashko <Grygorii.Strashko@linaro.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 include/linux/pid.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/pid.h b/include/linux/pid.h
index 14a9a39da9c7..a9026a5da196 100644
--- a/include/linux/pid.h
+++ b/include/linux/pid.h
@@ -3,6 +3,7 @@
 #define _LINUX_PID_H
 
 #include <linux/rculist.h>
+#include <linux/atomic.h>
 
 enum pid_type
 {