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author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2016-11-28 22:44:51 +0100 |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2016-11-29 23:34:11 +0100 |
commit | cb91fef1b71954e3edc79fb4171b43f6aa2028c7 (patch) | |
tree | 5747beae6c5944d1f4cd083eef43104dc4a67751 | |
parent | thermal/intel_powerclamp: Convert the kthread to kthread worker API (diff) | |
download | linux-cb91fef1b71954e3edc79fb4171b43f6aa2028c7.tar.xz linux-cb91fef1b71954e3edc79fb4171b43f6aa2028c7.zip |
thermal/intel_powerclamp: Convert to CPU hotplug state
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>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
-rw-r--r-- | drivers/thermal/intel_powerclamp.c | 73 |
1 files changed, 36 insertions, 37 deletions
diff --git a/drivers/thermal/intel_powerclamp.c b/drivers/thermal/intel_powerclamp.c index a94f7c849a4e..c99af71c0ae7 100644 --- a/drivers/thermal/intel_powerclamp.c +++ b/drivers/thermal/intel_powerclamp.c @@ -43,7 +43,6 @@ #include <linux/kernel.h> #include <linux/delay.h> #include <linux/kthread.h> -#include <linux/freezer.h> #include <linux/cpu.h> #include <linux/thermal.h> #include <linux/slab.h> @@ -530,8 +529,7 @@ static void start_power_clamp_worker(unsigned long cpu) struct powerclamp_worker_data *w_data = per_cpu_ptr(worker_data, cpu); struct kthread_worker *worker; - worker = kthread_create_worker_on_cpu(cpu, KTW_FREEZABLE, - "kidle_inject/%ld", cpu); + worker = kthread_create_worker_on_cpu(cpu, 0, "kidle_inject/%ld", cpu); if (IS_ERR(worker)) return; @@ -622,43 +620,35 @@ 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 +778,8 @@ file_error: debugfs_remove_recursive(debug_dir); } +static enum cpuhp_state hp_state; + static int __init powerclamp_init(void) { int retval; @@ -805,7 +797,14 @@ 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 +829,7 @@ 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 +838,8 @@ module_init(powerclamp_init); 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); |