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x86/oprofile/nmi: Convert to hotplug state machine 

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 <bigeasy@linutronix.de>
Cc: Robert Richter <rric@kernel.org>
Cc: oprofile-list@lists.sf.net
Cc: rt@linuxtronix.de
Link: http://lkml.kernel.org/r/20161117183541.8588-20-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Sebastian Andrzej Siewior 2016-11-17 19:35:40 +01:00 committed by Thomas Gleixner
parent 08ed487c81
commit 89666c5047
1 changed files with 18 additions and 43 deletions
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61
arch/x86/oprofile/nmi_int.c
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@ -339,10 +339,11 @@ static int allocate_msrs(void)
return 0;
}
static void nmi_cpu_setup(void *dummy)
static void nmi_cpu_setup(void)
{
int cpu = smp_processor_id();
struct op_msrs *msrs = &per_cpu(cpu_msrs, cpu);
nmi_cpu_save_registers(msrs);
raw_spin_lock(&oprofilefs_lock);
model->setup_ctrs(model, msrs);
@ -369,7 +370,7 @@ static void nmi_cpu_restore_registers(struct op_msrs *msrs)
}
}
static void nmi_cpu_shutdown(void *dummy)
static void nmi_cpu_shutdown(void)
{
unsigned int v;
int cpu = smp_processor_id();
@ -387,24 +388,26 @@ static void nmi_cpu_shutdown(void *dummy)
nmi_cpu_restore_registers(msrs);
}
static void nmi_cpu_up(void)
static int nmi_cpu_online(unsigned int cpu)
{
local_irq_disable();
if (nmi_enabled)
nmi_cpu_setup(NULL);
nmi_cpu_setup();
if (ctr_running)
nmi_cpu_start(NULL);
local_irq_enable();
return 0;
}
static void nmi_cpu_down(void)
static int nmi_cpu_down_prep(unsigned int cpu)
{
local_irq_disable();
if (ctr_running)
nmi_cpu_stop(NULL);
if (nmi_enabled)
nmi_cpu_shutdown(NULL);
nmi_cpu_shutdown();
local_irq_enable();
return 0;
}
static int nmi_create_files(struct dentry *root)
@ -437,24 +440,7 @@ static int nmi_create_files(struct dentry *root)
return 0;
}
static int oprofile_cpu_notifier(struct notifier_block *b, unsigned long action,
void *data)
{
switch (action & ~CPU_TASKS_FROZEN) {
case CPU_DOWN_FAILED:
case CPU_ONLINE:
nmi_cpu_up();
break;
case CPU_DOWN_PREPARE:
nmi_cpu_down();
break;
}
return NOTIFY_DONE;
}
static struct notifier_block oprofile_cpu_nb = {
.notifier_call = oprofile_cpu_notifier
};
static enum cpuhp_state cpuhp_nmi_online;
static int nmi_setup(void)
{
@ -497,20 +483,17 @@ static int nmi_setup(void)
if (err)
goto fail;
cpu_notifier_register_begin();
/* Use get/put_online_cpus() to protect 'nmi_enabled' */
get_online_cpus();
nmi_enabled = 1;
/* make nmi_enabled visible to the nmi handler: */
smp_mb();
on_each_cpu(nmi_cpu_setup, NULL, 1);
__register_cpu_notifier(&oprofile_cpu_nb);
put_online_cpus();
cpu_notifier_register_done();
err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/oprofile:online",
nmi_cpu_online, nmi_cpu_down_prep);
if (err < 0)
goto fail_nmi;
cpuhp_nmi_online = err;
return 0;
fail_nmi:
unregister_nmi_handler(NMI_LOCAL, "oprofile");
fail:
free_msrs();
return err;
@ -520,17 +503,9 @@ static void nmi_shutdown(void)
{
struct op_msrs *msrs;
cpu_notifier_register_begin();
/* Use get/put_online_cpus() to protect 'nmi_enabled' & 'ctr_running' */
get_online_cpus();
on_each_cpu(nmi_cpu_shutdown, NULL, 1);
cpuhp_remove_state(cpuhp_nmi_online);
nmi_enabled = 0;
ctr_running = 0;
__unregister_cpu_notifier(&oprofile_cpu_nb);
put_online_cpus();
cpu_notifier_register_done();
/* make variables visible to the nmi handler: */
smp_mb();