linux-kernel - [PATCH 3/5] sched: Complete cleanup of old vtime gen irqtime accounting

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Date:	Wed, 13 Jul 2016 16:50:03 +0200
From:	Frederic Weisbecker <fweisbec@...il.com>
To:	Ingo Molnar <mingo@...nel.org>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	Frederic Weisbecker <fweisbec@...il.com>,
	Paolo Bonzini <pbonzini@...hat.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Wanpeng Li <wanpeng.li@...mail.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Radim Krcmar <rkrcmar@...hat.com>,
	Mike Galbraith <efault@....de>, Rik van Riel <riel@...hat.com>
Subject: [PATCH 3/5] sched: Complete cleanup of old vtime gen irqtime accounting

Vtime generic irqtime accounting has been removed but there are a few
remains to cleanup:

* The vtime_accounting_cpu_enabled() check in irq entry was only used
  by CONFIG_VIRT_CPU_ACCOUNTING_GEN. We can safely remove it.

* Without the vtime_accounting_cpu_enabled(), we no longer need to
  have a vtime_common_account_irq_enter() indirect function.

* Move vtime_account_irq_enter() implementation under
  CONFIG_VIRT_CPU_ACCOUNTING_NATIVE which is the last user.

* The vtime_account_user() call was only used on irq entry for
  CONFIG_VIRT_CPU_ACCOUNTING_GEN. We can remove that too.

Cc: Rik van Riel <riel@...hat.com>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Ingo Molnar <mingo@...nel.org>
Cc: Paolo Bonzini <pbonzini@...hat.com>
Cc: Wanpeng Li <wanpeng.li@...mail.com>
Cc: Mike Galbraith <efault@....de>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Radim Krcmar <rkrcmar@...hat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@...il.com>
---
 include/linux/vtime.h  | 11 -----------
 kernel/sched/cputime.c | 33 ++++++++++-----------------------
 2 files changed, 10 insertions(+), 34 deletions(-)

diff --git a/include/linux/vtime.h b/include/linux/vtime.h
index d1977d84..65aef5e 100644
--- a/include/linux/vtime.h
+++ b/include/linux/vtime.h
@@ -14,18 +14,7 @@ struct task_struct;
  */
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 static inline bool vtime_accounting_cpu_enabled(void) { return true; }
-
-#ifdef __ARCH_HAS_VTIME_ACCOUNT
 extern void vtime_account_irq_enter(struct task_struct *tsk);
-#else
-extern void vtime_common_account_irq_enter(struct task_struct *tsk);
-static inline void vtime_account_irq_enter(struct task_struct *tsk)
-{
-	if (vtime_accounting_cpu_enabled())
-		vtime_common_account_irq_enter(tsk);
-}
-#endif /* __ARCH_HAS_VTIME_ACCOUNT */
-
 #endif /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
 
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index ca7e33c..16a873c 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -431,6 +431,10 @@ void vtime_common_task_switch(struct task_struct *prev)
 }
 #endif
 
+#endif /* CONFIG_VIRT_CPU_ACCOUNTING */
+
+
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 /*
  * Archs that account the whole time spent in the idle task
  * (outside irq) as idle time can rely on this and just implement
@@ -440,33 +444,16 @@ void vtime_common_task_switch(struct task_struct *prev)
  * vtime_account().
  */
 #ifndef __ARCH_HAS_VTIME_ACCOUNT
-void vtime_common_account_irq_enter(struct task_struct *tsk)
+void vtime_account_irq_enter(struct task_struct *tsk)
 {
-	if (!in_interrupt()) {
-		/*
-		 * If we interrupted user, context_tracking_in_user()
-		 * is 1 because the context tracking don't hook
-		 * on irq entry/exit. This way we know if
-		 * we need to flush user time on kernel entry.
-		 */
-		if (context_tracking_in_user()) {
-			vtime_account_user(tsk);
-			return;
-		}
-
-		if (is_idle_task(tsk)) {
-			vtime_account_idle(tsk);
-			return;
-		}
-	}
-	vtime_account_system(tsk);
+	if (!in_interrupt() && is_idle_task(tsk))
+		vtime_account_idle(tsk);
+	else
+		vtime_account_system(tsk);
 }
-EXPORT_SYMBOL_GPL(vtime_common_account_irq_enter);
+EXPORT_SYMBOL_GPL(vtime_account_irq_enter);
 #endif /* __ARCH_HAS_VTIME_ACCOUNT */
-#endif /* CONFIG_VIRT_CPU_ACCOUNTING */
 
-
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st)
 {
 	*ut = p->utime;
-- 
2.7.0