Commit 2b91ec9f authored by Frederic Weisbecker's avatar Frederic Weisbecker Committed by Thomas Gleixner
Browse files

s390/vtime: Use the generic IRQ entry accounting 



s390 has its own version of IRQ entry accounting because it doesn't
account the idle time the same way the other architectures do. Only
the actual idle sleep time is accounted as idle time, the rest of the
idle task execution is accounted as system time.

Make the generic IRQ entry accounting aware of architectures that have
their own way of accounting idle time and convert s390 to use it.

This prepares s390 to get involved in further consolidations of IRQ
time accounting.

Signed-off-by: default avatarFrederic Weisbecker <frederic@kernel.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201202115732.27827-3-frederic@kernel.org
parent 7197688b

arch/Kconfig

+6 −1
Original line number Diff line number Diff line
@@ -627,6 +627,12 @@ config HAVE_TIF_NOHZ 
config HAVE_VIRT_CPU_ACCOUNTING

	bool



config HAVE_VIRT_CPU_ACCOUNTING_IDLE

	bool

	help

	  Architecture has its own way to account idle CPU time and therefore

	  doesn't implement vtime_account_idle().



config ARCH_HAS_SCALED_CPUTIME

	bool
@@ -641,7 +647,6 @@ config HAVE_VIRT_CPU_ACCOUNTING_GEN 
	  some 32-bit arches may require multiple accesses, so proper

	  locking is needed to protect against concurrent accesses.





config HAVE_IRQ_TIME_ACCOUNTING

	bool

	help

arch/s390/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -181,6 +181,7 @@ config S390 
	select HAVE_RSEQ

	select HAVE_SYSCALL_TRACEPOINTS

	select HAVE_VIRT_CPU_ACCOUNTING

	select HAVE_VIRT_CPU_ACCOUNTING_IDLE

	select IOMMU_HELPER		if PCI

	select IOMMU_SUPPORT		if PCI

	select MODULES_USE_ELF_RELA

arch/s390/include/asm/vtime.h

+0 −1
Original line number Diff line number Diff line
@@ -2,7 +2,6 @@ 
#ifndef _S390_VTIME_H

#define _S390_VTIME_H



#define __ARCH_HAS_VTIME_ACCOUNT

#define __ARCH_HAS_VTIME_TASK_SWITCH



#endif /* _S390_VTIME_H */

arch/s390/kernel/vtime.c

+0 −4
Original line number Diff line number Diff line
@@ -247,10 +247,6 @@ void vtime_account_kernel(struct task_struct *tsk) 
}

EXPORT_SYMBOL_GPL(vtime_account_kernel);



void vtime_account_irq_enter(struct task_struct *tsk)

__attribute__((alias("vtime_account_kernel")));





/*

 * Sorted add to a list. List is linear searched until first bigger

 * element is found.

kernel/sched/cputime.c

+2 −11
Original line number Diff line number Diff line
@@ -417,23 +417,14 @@ void vtime_task_switch(struct task_struct *prev) 
}

# endif



/*

 * Archs that account the whole time spent in the idle task

 * (outside irq) as idle time can rely on this and just implement

 * vtime_account_kernel() and vtime_account_idle(). Archs that

 * have other meaning of the idle time (s390 only includes the

 * time spent by the CPU when it's in low power mode) must override

 * vtime_account().

 */

#ifndef __ARCH_HAS_VTIME_ACCOUNT

void vtime_account_irq_enter(struct task_struct *tsk)

{

	if (!in_interrupt() && is_idle_task(tsk))

	if (!IS_ENABLED(CONFIG_HAVE_VIRT_CPU_ACCOUNTING_IDLE) &&

	    !in_interrupt() && is_idle_task(tsk))

		vtime_account_idle(tsk);

	else

		vtime_account_kernel(tsk);

}

#endif /* __ARCH_HAS_VTIME_ACCOUNT */



void cputime_adjust(struct task_cputime *curr, struct prev_cputime *prev,

		    u64 *ut, u64 *st)

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