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authorSebastian Andrzej Siewior <bigeasy@linutronix.de>2016-09-06 20:04:45 +0300
committerThomas Gleixner <tglx@linutronix.de>2016-09-19 22:44:28 +0300
commita4e0591ece7d88634a802c4076db8c0debbde805 (patch)
treef6ecce0922ff64ac53d808e582589d6ad9eaa676
parent9a659f43dfea27cca423d4e80809be447f4c9ce7 (diff)
downloadlinux-a4e0591ece7d88634a802c4076db8c0debbde805.tar.xz
oprofile/timer: Convert to hotplug state machine
Install the callbacks via the state machine and let the core invoke the callbacks on the already online CPUs. Since the online target runs always on the target CPU we can drop smp_call_function_single(). The functions is invoked with interrupts off to keep the old calling convention. If the maintainer things that this function can be called with interrupts enabled then it can be removed :) Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Robert Richter <rric@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: oprofile-list@lists.sf.net Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160906170457.32393-10-bigeasy@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
-rw-r--r--drivers/oprofile/timer_int.c44
1 files changed, 23 insertions, 21 deletions
diff --git a/drivers/oprofile/timer_int.c b/drivers/oprofile/timer_int.c
index bdef916e5dda..2498a6cd7c24 100644
--- a/drivers/oprofile/timer_int.c
+++ b/drivers/oprofile/timer_int.c
@@ -74,37 +74,39 @@ static void oprofile_hrtimer_stop(void)
put_online_cpus();
}
-static int oprofile_cpu_notify(struct notifier_block *self,
- unsigned long action, void *hcpu)
+static int oprofile_timer_online(unsigned int cpu)
{
- long cpu = (long) hcpu;
-
- switch (action) {
- case CPU_ONLINE:
- case CPU_ONLINE_FROZEN:
- smp_call_function_single(cpu, __oprofile_hrtimer_start,
- NULL, 1);
- break;
- case CPU_DEAD:
- case CPU_DEAD_FROZEN:
- __oprofile_hrtimer_stop(cpu);
- break;
- }
- return NOTIFY_OK;
+ local_irq_disable();
+ __oprofile_hrtimer_start(NULL);
+ local_irq_enable();
+ return 0;
}
-static struct notifier_block __refdata oprofile_cpu_notifier = {
- .notifier_call = oprofile_cpu_notify,
-};
+static int oprofile_timer_prep_down(unsigned int cpu)
+{
+ __oprofile_hrtimer_stop(cpu);
+ return 0;
+}
+
+static enum cpuhp_state hp_online;
static int oprofile_hrtimer_setup(void)
{
- return register_hotcpu_notifier(&oprofile_cpu_notifier);
+ int ret;
+
+ ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
+ "oprofile/timer:online",
+ oprofile_timer_online,
+ oprofile_timer_prep_down);
+ if (ret < 0)
+ return ret;
+ hp_online = ret;
+ return 0;
}
static void oprofile_hrtimer_shutdown(void)
{
- unregister_hotcpu_notifier(&oprofile_cpu_notifier);
+ cpuhp_remove_state_nocalls(hp_online);
}
int oprofile_timer_init(struct oprofile_operations *ops)