mirror of
				https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux
				synced 2025-10-31 06:54:45 +10:00 
			
		
		
		
	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 <fweisbec@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> [fixed kvm module related build errors] Signed-off-by: Sedat Dilek <sedat.dilek@gmail.com>
		
			
				
	
	
		
			70 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			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 */
 |