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Commit e3d617fe authored by Sebastian Andrzej Siewior's avatar Sebastian Andrzej Siewior Committed by Ingo Molnar
Browse files

s390/perf: Convert the hotplug notifier to state machine callbacks (Sampling) 



Install the callbacks via the state machine and let the core invoke the
callbacks on the already online CPUs.

Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: default avatarAnna-Maria Gleixner <anna-maria@linutronix.de>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-s390@vger.kernel.org
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153334.518084858@linutronix.de


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 4f0f8217

arch/s390/kernel/perf_cpum_sf.c

+19 −26
Original line number Diff line number Diff line
@@ -1506,37 +1506,28 @@ static void cpumf_measurement_alert(struct ext_code ext_code, 
		sf_disable();

	}

}



static int cpumf_pmu_notifier(struct notifier_block *self,

			      unsigned long action, void *hcpu)

static int cpusf_pmu_setup(unsigned int cpu, int flags)

{

	int flags;



	/* Ignore the notification if no events are scheduled on the PMU.

	 * This might be racy...

	 */

	if (!atomic_read(&num_events))

		return NOTIFY_OK;

		return 0;



	switch (action & ~CPU_TASKS_FROZEN) {

	case CPU_ONLINE:

	case CPU_DOWN_FAILED:

		flags = PMC_INIT;

		local_irq_disable();

		setup_pmc_cpu(&flags);

		local_irq_enable();

		break;

	case CPU_DOWN_PREPARE:

		flags = PMC_RELEASE;

	local_irq_disable();

	setup_pmc_cpu(&flags);

	local_irq_enable();

		break;

	default:

		break;

	return 0;

}



static int s390_pmu_sf_online_cpu(unsigned int cpu)

{

	return cpusf_pmu_setup(cpu, PMC_INIT);

}



	return NOTIFY_OK;

static int s390_pmu_sf_offline_cpu(unsigned int cpu)

{

	return cpusf_pmu_setup(cpu, PMC_RELEASE);

}



static int param_get_sfb_size(char *buffer, const struct kernel_param *kp)
@@ -1636,7 +1627,9 @@ static int __init init_cpum_sampling_pmu(void) 
					cpumf_measurement_alert);

		goto out;

	}

	perf_cpu_notifier(cpumf_pmu_notifier);



	cpuhp_setup_state(CPUHP_AP_PERF_S390_SF_ONLINE, "AP_PERF_S390_SF_ONLINE",

			  s390_pmu_sf_online_cpu, s390_pmu_sf_offline_cpu);

out:

	return err;

}

include/linux/cpuhotplug.h

+1 −0
Original line number Diff line number Diff line
@@ -43,6 +43,7 @@ enum cpuhp_state { 
	CPUHP_AP_PERF_X86_CQM_ONLINE,

	CPUHP_AP_PERF_X86_CSTATE_ONLINE,

	CPUHP_AP_PERF_S390_CF_ONLINE,

	CPUHP_AP_PERF_S390_SF_ONLINE,

	CPUHP_AP_NOTIFY_ONLINE,

	CPUHP_AP_ONLINE_DYN,

	CPUHP_AP_ONLINE_DYN_END		= CPUHP_AP_ONLINE_DYN + 30,