Commit 3e1df4f5 authored by Frederic Weisbecker's avatar Frederic Weisbecker
Browse files

cputime: Separate irqtime accounting from generic vtime 



vtime_account() doesn't have the same role in
CONFIG_VIRT_CPU_ACCOUNTING and CONFIG_IRQ_TIME_ACCOUNTING.

In the first case it handles time accounting in any context. In
the second case it only handles irq time accounting.

So when vtime_account() is called from outside vtime_account_irq_*()
this call is pointless to CONFIG_IRQ_TIME_ACCOUNTING.

To fix the confusion, change vtime_account() to irqtime_account_irq()
in CONFIG_IRQ_TIME_ACCOUNTING. This way we ensure future account_vtime()
calls won't waste useless cycles in the irqtime APIs.

Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
parent fa5058f3

include/linux/vtime.h

+8 −10
Original line number Diff line number Diff line
@@ -8,17 +8,18 @@ extern void vtime_task_switch(struct task_struct *prev); 
extern void __vtime_account_system(struct task_struct *tsk);

extern void vtime_account_system(struct task_struct *tsk);

extern void __vtime_account_idle(struct task_struct *tsk);

extern void vtime_account(struct task_struct *tsk);

#else

static inline void vtime_task_switch(struct task_struct *prev) { }

static inline void __vtime_account_system(struct task_struct *tsk) { }

static inline void vtime_account_system(struct task_struct *tsk) { }

static inline void vtime_account(struct task_struct *tsk) { }

#endif



#if !defined(CONFIG_VIRT_CPU_ACCOUNTING) && !defined(CONFIG_IRQ_TIME_ACCOUNTING)

static inline void vtime_account(struct task_struct *tsk)

{

}

#ifdef CONFIG_IRQ_TIME_ACCOUNTING

extern void irqtime_account_irq(struct task_struct *tsk);

#else

extern void vtime_account(struct task_struct *tsk);

static inline void irqtime_account_irq(struct task_struct *tsk) { }

#endif



static inline void vtime_account_irq_enter(struct task_struct *tsk)
@@ -33,17 +34,14 @@ static inline void vtime_account_irq_enter(struct task_struct *tsk) 
	 * the idle time is flushed on hardirq time already.

	 */

	vtime_account(tsk);

	irqtime_account_irq(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

	irqtime_account_irq(tsk);

}



#endif /* _LINUX_KERNEL_VTIME_H */

kernel/sched/cputime.c

+2 −2
Original line number Diff line number Diff line
@@ -43,7 +43,7 @@ DEFINE_PER_CPU(seqcount_t, irq_time_seq); 
 * Called before incrementing preempt_count on {soft,}irq_enter

 * and before decrementing preempt_count on {soft,}irq_exit.

 */

void vtime_account(struct task_struct *curr)

void irqtime_account_irq(struct task_struct *curr)

{

	unsigned long flags;

	s64 delta;
@@ -73,7 +73,7 @@ void vtime_account(struct task_struct *curr) 
	irq_time_write_end();

	local_irq_restore(flags);

}

EXPORT_SYMBOL_GPL(vtime_account);

EXPORT_SYMBOL_GPL(irqtime_account_irq);



static int irqtime_account_hi_update(void)

{