From e3d617fe6ac7294974fc513dc5e4d8ada8080fd1 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Wed, 13 Jul 2016 17:16:22 +0000 Subject: [PATCH] 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: Sebastian Andrzej Siewior Signed-off-by: Anna-Maria Gleixner Cc: Christian Borntraeger Cc: Heiko Carstens Cc: Hendrik Brueckner Cc: Linus Torvalds Cc: Martin Schwidefsky Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-s390@vger.kernel.org Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160713153334.518084858@linutronix.de Signed-off-by: Ingo Molnar --- arch/s390/kernel/perf_cpum_sf.c | 43 ++++++++++++++------------------- include/linux/cpuhotplug.h | 1 + 2 files changed, 19 insertions(+), 25 deletions(-) diff --git a/arch/s390/kernel/perf_cpum_sf.c b/arch/s390/kernel/perf_cpum_sf.c index a8e832166417..f4a4c118f8b4 100644 --- a/arch/s390/kernel/perf_cpum_sf.c +++ b/arch/s390/kernel/perf_cpum_sf.c @@ -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; - } + local_irq_disable(); + setup_pmc_cpu(&flags); + local_irq_enable(); + return 0; +} - return NOTIFY_OK; +static int s390_pmu_sf_online_cpu(unsigned int cpu) +{ + return cpusf_pmu_setup(cpu, PMC_INIT); +} + +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; } diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index d4e09cb0c100..fea66667d190 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -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,