From: Petr Mladek <pmladek@suse.com>
To: Jacob Pan <jacob.jun.pan@linux.intel.com>,
Zhang Rui <rui.zhang@intel.com>,
Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Eduardo Valentin <edubezval@gmail.com>, Tejun Heo <tj@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
Petr Mladek <pmladek@suse.com>
Subject: [PATCH 3/3] thermal/intel_powerclamp: Convert to CPU hotplug state
Date: Mon, 17 Oct 2016 14:32:52 +0200 [thread overview]
Message-ID: <1476707572-32215-4-git-send-email-pmladek@suse.com> (raw)
In-Reply-To: <1476707572-32215-1-git-send-email-pmladek@suse.com>
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
This is a conversation to the new hotplug state machine with
the difference that CPU_DEAD becomes CPU_PREDOWN.
At the same time it makes the handling of the two states symmetrical.
stop_power_clamp_worker() is called unconditionally and the controversial
error message is removed.
Finally, the hotplug state callbacks are removed after the powerclamping
is stopped to avoid a potential race.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
[pmladek@suse.com: Fixed the possible race in powerclamp_exit()]
Signed-off-by: Petr Mladek <pmladek@suse.com>
---
drivers/thermal/intel_powerclamp.c | 69 +++++++++++++++++++-------------------
1 file changed, 35 insertions(+), 34 deletions(-)
diff --git a/drivers/thermal/intel_powerclamp.c b/drivers/thermal/intel_powerclamp.c
index a94f7c849a4e..390e50b97324 100644
--- a/drivers/thermal/intel_powerclamp.c
+++ b/drivers/thermal/intel_powerclamp.c
@@ -622,43 +622,35 @@ static void end_power_clamp(void)
}
}
-static int powerclamp_cpu_callback(struct notifier_block *nfb,
- unsigned long action, void *hcpu)
+static int powerclamp_cpu_online(unsigned int cpu)
{
- unsigned long cpu = (unsigned long)hcpu;
+ if (clamping == false)
+ return 0;
+ start_power_clamp_worker(cpu);
+ /* prefer BSP as controlling CPU */
+ if (cpu == 0) {
+ control_cpu = 0;
+ smp_mb();
+ }
+ return 0;
+}
- if (false == clamping)
- goto exit_ok;
+static int powerclamp_cpu_predown(unsigned int cpu)
+{
+ if (clamping == false)
+ return 0;
- switch (action) {
- case CPU_ONLINE:
- start_power_clamp_worker(cpu);
- /* prefer BSP as controlling CPU */
- if (cpu == 0) {
- control_cpu = 0;
- smp_mb();
- }
- break;
- case CPU_DEAD:
- if (test_bit(cpu, cpu_clamping_mask)) {
- pr_err("cpu %lu dead but powerclamping thread is not\n",
- cpu);
- stop_power_clamp_worker(cpu);
- }
- if (cpu == control_cpu) {
- control_cpu = smp_processor_id();
- smp_mb();
- }
- }
+ stop_power_clamp_worker(cpu);
+ if (cpu != control_cpu)
+ return 0;
-exit_ok:
- return NOTIFY_OK;
+ control_cpu = cpumask_first(cpu_online_mask);
+ if (control_cpu == cpu)
+ control_cpu = cpumask_next(cpu, cpu_online_mask);
+ smp_mb();
+ return 0;
}
-static struct notifier_block powerclamp_cpu_notifier = {
- .notifier_call = powerclamp_cpu_callback,
-};
-
static int powerclamp_get_max_state(struct thermal_cooling_device *cdev,
unsigned long *state)
{
@@ -788,6 +780,8 @@ static inline void powerclamp_create_debug_files(void)
debugfs_remove_recursive(debug_dir);
}
+static enum cpuhp_state hp_state;
+
static int __init powerclamp_init(void)
{
int retval;
@@ -805,7 +799,14 @@ static int __init powerclamp_init(void)
/* set default limit, maybe adjusted during runtime based on feedback */
window_size = 2;
- register_hotcpu_notifier(&powerclamp_cpu_notifier);
+ retval = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
+ "thermal/intel_powerclamp:online",
+ powerclamp_cpu_online,
+ powerclamp_cpu_predown);
+ if (retval < 0)
+ goto exit_free;
+
+ hp_state = retval;
worker_data = alloc_percpu(struct powerclamp_worker_data);
if (!worker_data) {
@@ -830,7 +831,7 @@ static int __init powerclamp_init(void)
exit_free_thread:
free_percpu(worker_data);
exit_unregister:
- unregister_hotcpu_notifier(&powerclamp_cpu_notifier);
+ cpuhp_remove_state_nocalls(hp_state);
exit_free:
kfree(cpu_clamping_mask);
return retval;
@@ -839,8 +840,8 @@ static int __init powerclamp_init(void)
static void __exit powerclamp_exit(void)
{
- unregister_hotcpu_notifier(&powerclamp_cpu_notifier);
end_power_clamp();
+ cpuhp_remove_state_nocalls(hp_state);
free_percpu(worker_data);
thermal_cooling_device_unregister(cooling_dev);
kfree(cpu_clamping_mask);
--
1.8.5.6
next prev parent reply other threads:[~2016-10-17 12:34 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-17 12:32 [PATCH 0/3] thermal/intel_powerclamp: Conversion to kthread worker API and new CPU hotplug state Petr Mladek
2016-10-17 12:32 ` [PATCH 1/3] thermal/intel_powerclamp: Remove duplicated code that starts the kthread Petr Mladek
2016-10-17 12:32 ` [PATCH 2/3] thermal/intel_powerclamp: Convert the kthread to kthread worker API Petr Mladek
2016-10-17 12:32 ` Petr Mladek [this message]
2016-10-21 20:21 ` [PATCH 3/3] thermal/intel_powerclamp: Convert to CPU hotplug state Jacob Pan
2016-10-24 15:48 ` Petr Mladek
2016-10-24 16:55 ` Jacob Pan
2016-10-27 14:53 ` Petr Mladek
2016-10-27 15:17 ` Sebastian Andrzej Siewior
2016-10-27 20:27 ` Jacob Pan
2016-11-11 9:33 ` Petr Mladek
2016-11-11 10:07 ` Petr Mladek
2016-11-11 17:34 ` Petr Mladek
2016-11-14 19:12 ` Jacob Pan
2016-11-15 11:36 ` Zhang Rui
2016-11-15 16:40 ` Jacob Pan
2016-11-21 11:57 ` Petr Mladek
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