Files
erofs-linux/include/linux/vtime.h
T
Frederic Weisbecker 6a61671bb2 cputime: Safely read cputime of full dynticks CPUs
While remotely reading the cputime of a task running in a
full dynticks CPU, the values stored in utime/stime fields
of struct task_struct may be stale. Its values may be those
of the last kernel <-> user transition time snapshot and
we need to add the tickless time spent since this snapshot.

To fix this, flush the cputime of the dynticks CPUs on
kernel <-> user transition and record the time / context
where we did this. Then on top of this snapshot and the current
time, perform the fixup on the reader side from task_times()
accessors.

Signed-off-by: Frederic Weisbecker <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Li Zhong <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: Paul Gortmaker <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Thomas Gleixner <[email protected]>
[fixed kvm module related build errors]
Signed-off-by: Sedat Dilek <[email protected]>
2013-01-27 20:35:47 +01:00

70 lines
2.3 KiB
C

#ifndef _LINUX_KERNEL_VTIME_H
#define _LINUX_KERNEL_VTIME_H
struct task_struct;
#ifdef CONFIG_VIRT_CPU_ACCOUNTING
extern void vtime_task_switch(struct task_struct *prev);
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);
extern void vtime_account_irq_enter(struct task_struct *tsk);
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
static inline bool vtime_accounting_enabled(void) { return true; }
#endif
#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) { }
static inline bool vtime_accounting_enabled(void) { return false; }
#endif
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
extern void arch_vtime_task_switch(struct task_struct *tsk);
extern void vtime_account_irq_exit(struct task_struct *tsk);
extern bool vtime_accounting_enabled(void);
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);
#else
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) { }
#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 */