Commit 6472a2dc authored by Heiko Carstens's avatar Heiko Carstens
Browse files

s390/irq,idle: simplify idle check 



Use the per-cpu CIF_ENABLED_WAIT flag to decide if an interrupt
occurred while a cpu was idle, instead of checking two conditions
within the old psw.

Also move clearing of the CIF_ENABLED_WAIT bit to the early interrupt
handler, which in turn makes arch_vcpu_is_preempted() also a bit more
precise, since the flag is now cleared before interrupt handlers have
been called.

Reviewed-by: default avatarSven Schnelle <svens@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
parent f96f41aa

arch/s390/include/asm/idle.h

+0 −1
Original line number Diff line number Diff line
@@ -23,6 +23,5 @@ extern struct device_attribute dev_attr_idle_count; 
extern struct device_attribute dev_attr_idle_time_us;



void psw_idle(struct s390_idle_data *data, unsigned long psw_mask);

void psw_idle_exit(void);



#endif /* _S390_IDLE_H */

arch/s390/kernel/idle.c

+0 −1
Original line number Diff line number Diff line
@@ -28,7 +28,6 @@ void account_idle_time_irq(void) 
	u64 cycles_new[8];

	int i;



	clear_cpu_flag(CIF_ENABLED_WAIT);

	if (smp_cpu_mtid) {

		stcctm(MT_DIAG, smp_cpu_mtid, cycles_new);

		for (i = 0; i < smp_cpu_mtid; i++)

arch/s390/kernel/irq.c

+4 −4
Original line number Diff line number Diff line
@@ -136,7 +136,7 @@ void noinstr do_io_irq(struct pt_regs *regs) 
{

	irqentry_state_t state = irqentry_enter(regs);

	struct pt_regs *old_regs = set_irq_regs(regs);

	int from_idle;

	bool from_idle;



	irq_enter_rcu();
@@ -146,7 +146,7 @@ void noinstr do_io_irq(struct pt_regs *regs) 
			current->thread.last_break = regs->last_break;

	}



	from_idle = !user_mode(regs) && regs->psw.addr == (unsigned long)psw_idle_exit;

	from_idle = test_and_clear_cpu_flag(CIF_ENABLED_WAIT);

	if (from_idle)

		account_idle_time_irq();
@@ -171,7 +171,7 @@ void noinstr do_ext_irq(struct pt_regs *regs) 
{

	irqentry_state_t state = irqentry_enter(regs);

	struct pt_regs *old_regs = set_irq_regs(regs);

	int from_idle;

	bool from_idle;



	irq_enter_rcu();
@@ -185,7 +185,7 @@ void noinstr do_ext_irq(struct pt_regs *regs) 
	regs->int_parm = S390_lowcore.ext_params;

	regs->int_parm_long = S390_lowcore.ext_params2;



	from_idle = !user_mode(regs) && regs->psw.addr == (unsigned long)psw_idle_exit;

	from_idle = test_and_clear_cpu_flag(CIF_ENABLED_WAIT);

	if (from_idle)

		account_idle_time_irq();