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Commit 11ab244c authored by Heiko Carstens's avatar Heiko Carstens Committed by Martin Schwidefsky
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[S390] Make sure enabled wait psw is loaded in default_idle. 



If both NO_IDLE_HZ and VIRT_TIMER are disabled default_idle won't load
an enabled wait psw and busy loop instead. This is because the
idle_chain is empty and the return value of atomic_notifier_call_chain
will be NOTIFY_DONE, which causes default_idle to return instead of
loading an enabled wait psw.
Fix this by calling __atomic_notifier_call_chain instead and add proper
return value handling.

Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 057c5cb3

arch/s390/kernel/process.c

+9 −6
Original line number Diff line number Diff line
@@ -114,24 +114,27 @@ extern void s390_handle_mcck(void); 
static void default_idle(void)

{

	int cpu, rc;

	int nr_calls = 0;

	void *hcpu;

#ifdef CONFIG_SMP

	struct s390_idle_data *idle;

#endif



	/* CPU is going idle. */

	cpu = smp_processor_id();



	hcpu = (void *)(long)cpu;

	local_irq_disable();

	if (need_resched()) {

		local_irq_enable();

		return;

	}



	rc = atomic_notifier_call_chain(&idle_chain,

					S390_CPU_IDLE, (void *)(long) cpu);

	if (rc != NOTIFY_OK && rc != NOTIFY_DONE)

		BUG();

	if (rc != NOTIFY_OK) {

	rc = __atomic_notifier_call_chain(&idle_chain, S390_CPU_IDLE, hcpu, -1,

					  &nr_calls);

	if (rc == NOTIFY_BAD) {

		nr_calls--;

		__atomic_notifier_call_chain(&idle_chain, S390_CPU_NOT_IDLE,

					     hcpu, nr_calls, NULL);

		local_irq_enable();

		return;

	}