[patch V2 46/67] metag/perf: Convert to hotplug state machine

Anna-Maria Gleixner
2016-07-13T17:16:49Z

[-- Attachment #1: 0045-metag-perf-Convert-to-hotplug-state-machine.patch --]
[-- Type: text/plain, Size: 2893 bytes --]

From: Richard Cochran <rcochran@linutronix.de>

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

Signed-off-by: Richard Cochran <rcochran@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-metag@vger.kernel.org
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
---
arch/metag/kernel/perf/perf_event.c | 26 +++++++-------------------
include/linux/cpuhotplug.h | 1 +
2 files changed, 8 insertions(+), 19 deletions(-)

diff --git a/arch/metag/kernel/perf/perf_event.c b/arch/metag/kernel/perf/perf_event.c
index 33a365f..052cba2 100644
--- a/arch/metag/kernel/perf/perf_event.c
+++ b/arch/metag/kernel/perf/perf_event.c
@@ -806,25 +806,16 @@ static struct metag_pmu _metag_pmu = {
};

/* PMU CPU hotplug notifier */
-static int metag_pmu_cpu_notify(struct notifier_block *b, unsigned long action,
- void *hcpu)
+static int metag_pmu_starting_cpu(unsigned int cpu)
{
- unsigned int cpu = (unsigned int)hcpu;
struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu);

- if ((action & ~CPU_TASKS_FROZEN) != CPU_STARTING)
- return NOTIFY_DONE;
-
memset(cpuc, 0, sizeof(struct cpu_hw_events));
raw_spin_lock_init(&cpuc->pmu_lock);

- return NOTIFY_OK;
+ return 0;
}

-static struct notifier_block metag_pmu_notifier = {
- .notifier_call = metag_pmu_cpu_notify,
-};
-
/* PMU Initialisation */
static int __init init_hw_perf_events(void)
{
@@ -876,16 +867,13 @@ static int __init init_hw_perf_events(void)
metag_out32(0, PERF_COUNT(0));
metag_out32(0, PERF_COUNT(1));

- for_each_possible_cpu(cpu) {
- struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu);
+ cpuhp_setup_state(CPUHP_AP_PERF_METAG_STARTING,
+ "AP_PERF_METAG_STARTING", metag_pmu_starting_cpu,
+ NULL);

- memset(cpuc, 0, sizeof(struct cpu_hw_events));
- raw_spin_lock_init(&cpuc->pmu_lock);
- }
-
- register_cpu_notifier(&metag_pmu_notifier);
ret = perf_pmu_register(&pmu, metag_pmu->name, PERF_TYPE_RAW);
-out:
+ if (ret)
+ cpuhp_remove_state_nocalls(CPUHP_AP_PERF_METAG_STARTING);
return ret;
}
early_initcall(init_hw_perf_events);
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 0a36e61..5c66102 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -35,6 +35,7 @@ enum cpuhp_state {
CPUHP_AP_PERF_X86_CQM_STARTING,
CPUHP_AP_PERF_X86_CSTATE_STARTING,
CPUHP_AP_PERF_XTENSA_STARTING,
+ CPUHP_AP_PERF_METAG_STARTING,
CPUHP_AP_ARM_VFP_STARTING,
CPUHP_AP_PERF_ARM_STARTING,
CPUHP_AP_ARM_ARCH_TIMER_STARTING,
--
2.8.1