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-rw-r--r--kernels/linux-libre-rt/defer-thermal-wakups-to-threads.patch143
1 files changed, 143 insertions, 0 deletions
diff --git a/kernels/linux-libre-rt/defer-thermal-wakups-to-threads.patch b/kernels/linux-libre-rt/defer-thermal-wakups-to-threads.patch
new file mode 100644
index 000000000..451242da3
--- /dev/null
+++ b/kernels/linux-libre-rt/defer-thermal-wakups-to-threads.patch
@@ -0,0 +1,143 @@
+From 8334ac498f104c00e5d93e3e83d3bcec1a993cec Mon Sep 17 00:00:00 2001
+From: Daniel Wagner <wagi@monom.org>
+Date: Tue, 17 Feb 2015 09:37:44 +0100
+Subject: [PATCH] thermal: Defer thermal wakups to threads
+
+On RT the spin lock in pkg_temp_thermal_platfrom_thermal_notify will
+call schedule while we run in irq context.
+
+[<ffffffff816850ac>] dump_stack+0x4e/0x8f
+[<ffffffff81680f7d>] __schedule_bug+0xa6/0xb4
+[<ffffffff816896b4>] __schedule+0x5b4/0x700
+[<ffffffff8168982a>] schedule+0x2a/0x90
+[<ffffffff8168a8b5>] rt_spin_lock_slowlock+0xe5/0x2d0
+[<ffffffff8168afd5>] rt_spin_lock+0x25/0x30
+[<ffffffffa03a7b75>] pkg_temp_thermal_platform_thermal_notify+0x45/0x134 [x86_pkg_temp_thermal]
+[<ffffffff8103d4db>] ? therm_throt_process+0x1b/0x160
+[<ffffffff8103d831>] intel_thermal_interrupt+0x211/0x250
+[<ffffffff8103d8c1>] smp_thermal_interrupt+0x21/0x40
+[<ffffffff8169415d>] thermal_interrupt+0x6d/0x80
+
+Let's defer the work to a kthread.
+
+Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
+[bigeasy: reoder init/denit position. TODO: flush swork on exit]
+Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+---
+ drivers/thermal/x86_pkg_temp_thermal.c | 51 ++++++++++++++++++++++++++++++++--
+ 1 file changed, 48 insertions(+), 3 deletions(-)
+
+diff --git a/drivers/thermal/x86_pkg_temp_thermal.c b/drivers/thermal/x86_pkg_temp_thermal.c
+index 9ea3d9d49ffc..ab7c400a9d5c 100644
+--- a/drivers/thermal/x86_pkg_temp_thermal.c
++++ b/drivers/thermal/x86_pkg_temp_thermal.c
+@@ -29,6 +29,7 @@
+ #include <linux/pm.h>
+ #include <linux/thermal.h>
+ #include <linux/debugfs.h>
++#include <linux/work-simple.h>
+ #include <asm/cpu_device_id.h>
+ #include <asm/mce.h>
+
+@@ -352,7 +353,7 @@ static void pkg_temp_thermal_threshold_work_fn(struct work_struct *work)
+ }
+ }
+
+-static int pkg_temp_thermal_platform_thermal_notify(__u64 msr_val)
++static void platform_thermal_notify_work(struct swork_event *event)
+ {
+ unsigned long flags;
+ int cpu = smp_processor_id();
+@@ -369,7 +370,7 @@ static int pkg_temp_thermal_platform_thermal_notify(__u64 msr_val)
+ pkg_work_scheduled[phy_id]) {
+ disable_pkg_thres_interrupt();
+ spin_unlock_irqrestore(&pkg_work_lock, flags);
+- return -EINVAL;
++ return;
+ }
+ pkg_work_scheduled[phy_id] = 1;
+ spin_unlock_irqrestore(&pkg_work_lock, flags);
+@@ -378,9 +379,48 @@ static int pkg_temp_thermal_platform_thermal_notify(__u64 msr_val)
+ schedule_delayed_work_on(cpu,
+ &per_cpu(pkg_temp_thermal_threshold_work, cpu),
+ msecs_to_jiffies(notify_delay_ms));
++}
++
++#ifdef CONFIG_PREEMPT_RT_FULL
++static struct swork_event notify_work;
++
++static int thermal_notify_work_init(void)
++{
++ int err;
++
++ err = swork_get();
++ if (!err)
++ return err;
++
++ INIT_SWORK(&notify_work, platform_thermal_notify_work);
+ return 0;
+ }
+
++static void thermal_notify_work_cleanup(void)
++{
++ swork_put();
++}
++
++static int pkg_temp_thermal_platform_thermal_notify(__u64 msr_val)
++{
++ swork_queue(&notify_work);
++ return 0;
++}
++
++#else /* !CONFIG_PREEMPT_RT_FULL */
++
++static int thermal_notify_work_init(void) { return 0; }
++
++static int thermal_notify_work_cleanup(void) { }
++
++static int pkg_temp_thermal_platform_thermal_notify(__u64 msr_val)
++{
++ platform_thermal_notify_work(NULL);
++
++ return 0;
++}
++#endif /* CONFIG_PREEMPT_RT_FULL */
++
+ static int find_siblings_cpu(int cpu)
+ {
+ int i;
+@@ -584,6 +624,9 @@ static int __init pkg_temp_thermal_init(void)
+ if (!x86_match_cpu(pkg_temp_thermal_ids))
+ return -ENODEV;
+
++ if (!thermal_notify_work_init())
++ return -ENODEV;
++
+ spin_lock_init(&pkg_work_lock);
+ platform_thermal_package_notify =
+ pkg_temp_thermal_platform_thermal_notify;
+@@ -594,6 +637,7 @@ static int __init pkg_temp_thermal_init(void)
+ for_each_online_cpu(i)
+ if (get_core_online(i))
+ goto err_ret;
++
+ __register_hotcpu_notifier(&pkg_temp_thermal_notifier);
+ cpu_notifier_register_done();
+
+@@ -608,7 +652,7 @@ static int __init pkg_temp_thermal_init(void)
+ kfree(pkg_work_scheduled);
+ platform_thermal_package_notify = NULL;
+ platform_thermal_package_rate_control = NULL;
+-
++ thermal_notify_work_cleanup();
+ return -ENODEV;
+ }
+
+@@ -633,6 +677,7 @@ static void __exit pkg_temp_thermal_exit(void)
+ mutex_unlock(&phy_dev_list_mutex);
+ platform_thermal_package_notify = NULL;
+ platform_thermal_package_rate_control = NULL;
++ thermal_notify_work_cleanup();
+ for_each_online_cpu(i)
+ cancel_delayed_work_sync(
+ &per_cpu(pkg_temp_thermal_threshold_work, i));