From fb408cd5617b85291a046d7755a6fe5ed85a8ff8 Mon Sep 17 00:00:00 2001
From: Frederic Weisbecker <fweisbec@gmail.com>
Date: Sat, 6 Oct 2012 04:07:19 +0200
Subject: [PATCH] --- yaml --- r: 339081 b: refs/heads/master c:
 fa5058f3b63153e0147ef65bcdb3a4ee63581346 h: refs/heads/master i:   339079:
 68f3ac88c2a77fbaf89f6f531e4cd26d015ad7c9 v: v3

---
 [refs]                        |  2 +-
 trunk/include/linux/hardirq.h |  4 ++--
 trunk/include/linux/vtime.h   | 25 +++++++++++++++++++++++++
 trunk/kernel/softirq.c        |  6 +++---
 4 files changed, 31 insertions(+), 6 deletions(-)

diff --git a/[refs] b/[refs]
index 8bf1cc8b99ec..52c17f9a0ce9 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: b080935c8638e08134629d0a9ebdf35669bec14d
+refs/heads/master: fa5058f3b63153e0147ef65bcdb3a4ee63581346
diff --git a/trunk/include/linux/hardirq.h b/trunk/include/linux/hardirq.h
index b083a475423d..624ef3f45c8e 100644
--- a/trunk/include/linux/hardirq.h
+++ b/trunk/include/linux/hardirq.h
@@ -153,7 +153,7 @@ extern void rcu_nmi_exit(void);
  */
 #define __irq_enter()					\
 	do {						\
-		vtime_account(current);		\
+		vtime_account_irq_enter(current);	\
 		add_preempt_count(HARDIRQ_OFFSET);	\
 		trace_hardirq_enter();			\
 	} while (0)
@@ -169,7 +169,7 @@ extern void irq_enter(void);
 #define __irq_exit()					\
 	do {						\
 		trace_hardirq_exit();			\
-		vtime_account(current);		\
+		vtime_account_irq_exit(current);	\
 		sub_preempt_count(HARDIRQ_OFFSET);	\
 	} while (0)
 
diff --git a/trunk/include/linux/vtime.h b/trunk/include/linux/vtime.h
index b9fc4f9ab470..c35c02223da8 100644
--- a/trunk/include/linux/vtime.h
+++ b/trunk/include/linux/vtime.h
@@ -21,4 +21,29 @@ static inline void vtime_account(struct task_struct *tsk)
 extern void vtime_account(struct task_struct *tsk);
 #endif
 
+static inline void vtime_account_irq_enter(struct task_struct *tsk)
+{
+	/*
+	 * Hardirq can interrupt idle task anytime. So we need vtime_account()
+	 * that performs the idle check in CONFIG_VIRT_CPU_ACCOUNTING.
+	 * Softirq can also interrupt idle task directly if it calls
+	 * local_bh_enable(). Such case probably don't exist but we never know.
+	 * Ksoftirqd is not concerned because idle time is flushed on context
+	 * switch. Softirqs in the end of hardirqs are also not a problem because
+	 * the idle time is flushed on hardirq time already.
+	 */
+	vtime_account(tsk);
+}
+
+static inline void vtime_account_irq_exit(struct task_struct *tsk)
+{
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+	/* On hard|softirq exit we always account to hard|softirq cputime */
+	__vtime_account_system(tsk);
+#endif
+#ifdef CONFIG_IRQ_TIME_ACCOUNTING
+	vtime_account(tsk);
+#endif
+}
+
 #endif /* _LINUX_KERNEL_VTIME_H */
diff --git a/trunk/kernel/softirq.c b/trunk/kernel/softirq.c
index cc96bdc0c2c9..ed567babe789 100644
--- a/trunk/kernel/softirq.c
+++ b/trunk/kernel/softirq.c
@@ -221,7 +221,7 @@ asmlinkage void __do_softirq(void)
 	current->flags &= ~PF_MEMALLOC;
 
 	pending = local_softirq_pending();
-	vtime_account(current);
+	vtime_account_irq_enter(current);
 
 	__local_bh_disable((unsigned long)__builtin_return_address(0),
 				SOFTIRQ_OFFSET);
@@ -272,7 +272,7 @@ asmlinkage void __do_softirq(void)
 
 	lockdep_softirq_exit();
 
-	vtime_account(current);
+	vtime_account_irq_exit(current);
 	__local_bh_enable(SOFTIRQ_OFFSET);
 	tsk_restore_flags(current, old_flags, PF_MEMALLOC);
 }
@@ -341,7 +341,7 @@ static inline void invoke_softirq(void)
  */
 void irq_exit(void)
 {
-	vtime_account(current);
+	vtime_account_irq_exit(current);
 	trace_hardirq_exit();
 	sub_preempt_count(IRQ_EXIT_OFFSET);
 	if (!in_interrupt() && local_softirq_pending())