linux-hardened/include/linux/vtime.h
Frederic Weisbecker e592539466 sched/cputime: Introduce vtime accounting check for readers
Readers need to know if vtime runs at all on some CPU somewhere, this
is a fast-path check to determine if we need to check further the need
to add up any tickless cputime delta.

This fast path check uses context tracking state because vtime is tied
to context tracking as of now. This check appears to be confusing though
so lets use a vtime function that deals with context tracking details
in vtime implementation instead.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E . McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1447948054-28668-7-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-12-04 10:34:45 +01:00

136 lines
4 KiB
C

#ifndef _LINUX_KERNEL_VTIME_H
#define _LINUX_KERNEL_VTIME_H
#include <linux/context_tracking_state.h>
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
#include <asm/vtime.h>
#endif
struct task_struct;
/*
* vtime_accounting_cpu_enabled() definitions/declarations
*/
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
static inline bool vtime_accounting_cpu_enabled(void) { return true; }
#endif /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
/*
* Checks if vtime is enabled on some CPU. Cputime readers want to be careful
* in that case and compute the tickless cputime.
* For now vtime state is tied to context tracking. We might want to decouple
* those later if necessary.
*/
static inline bool vtime_accounting_enabled(void)
{
return context_tracking_is_enabled();
}
static inline bool vtime_accounting_cpu_enabled(void)
{
if (vtime_accounting_enabled()) {
if (context_tracking_cpu_is_enabled())
return true;
}
return false;
}
#endif /* CONFIG_VIRT_CPU_ACCOUNTING_GEN */
#ifndef CONFIG_VIRT_CPU_ACCOUNTING
static inline bool vtime_accounting_cpu_enabled(void) { return false; }
#endif /* !CONFIG_VIRT_CPU_ACCOUNTING */
/*
* Common vtime APIs
*/
#ifdef CONFIG_VIRT_CPU_ACCOUNTING
#ifdef __ARCH_HAS_VTIME_TASK_SWITCH
extern void vtime_task_switch(struct task_struct *prev);
#else
extern void vtime_common_task_switch(struct task_struct *prev);
static inline void vtime_task_switch(struct task_struct *prev)
{
if (vtime_accounting_cpu_enabled())
vtime_common_task_switch(prev);
}
#endif /* __ARCH_HAS_VTIME_TASK_SWITCH */
extern void vtime_account_system(struct task_struct *tsk);
extern void vtime_account_idle(struct task_struct *tsk);
extern void vtime_account_user(struct task_struct *tsk);
#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 */
#else /* !CONFIG_VIRT_CPU_ACCOUNTING */
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_user(struct task_struct *tsk) { }
static inline void vtime_account_irq_enter(struct task_struct *tsk) { }
#endif /* !CONFIG_VIRT_CPU_ACCOUNTING */
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
extern void arch_vtime_task_switch(struct task_struct *tsk);
extern void vtime_gen_account_irq_exit(struct task_struct *tsk);
static inline void vtime_account_irq_exit(struct task_struct *tsk)
{
if (vtime_accounting_cpu_enabled())
vtime_gen_account_irq_exit(tsk);
}
extern void vtime_user_enter(struct task_struct *tsk);
static inline void vtime_user_exit(struct task_struct *tsk)
{
vtime_account_user(tsk);
}
extern void vtime_guest_enter(struct task_struct *tsk);
extern void vtime_guest_exit(struct task_struct *tsk);
extern void vtime_init_idle(struct task_struct *tsk, int cpu);
#else /* !CONFIG_VIRT_CPU_ACCOUNTING_GEN */
static inline void vtime_account_irq_exit(struct task_struct *tsk)
{
/* On hard|softirq exit we always account to hard|softirq cputime */
vtime_account_system(tsk);
}
static inline void vtime_user_enter(struct task_struct *tsk) { }
static inline void vtime_user_exit(struct task_struct *tsk) { }
static inline void vtime_guest_enter(struct task_struct *tsk) { }
static inline void vtime_guest_exit(struct task_struct *tsk) { }
static inline void vtime_init_idle(struct task_struct *tsk, int cpu) { }
#endif
#ifdef CONFIG_IRQ_TIME_ACCOUNTING
extern void irqtime_account_irq(struct task_struct *tsk);
#else
static inline void irqtime_account_irq(struct task_struct *tsk) { }
#endif
static inline void account_irq_enter_time(struct task_struct *tsk)
{
vtime_account_irq_enter(tsk);
irqtime_account_irq(tsk);
}
static inline void account_irq_exit_time(struct task_struct *tsk)
{
vtime_account_irq_exit(tsk);
irqtime_account_irq(tsk);
}
#endif /* _LINUX_KERNEL_VTIME_H */