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Jetpack/kernel/kernel-4.9/rt-patches/0205-x86-Convert-mce-timer-...

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From 846ea583b427c227ab18830bd55c344018dc7de5 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Mon, 13 Dec 2010 16:33:39 +0100
Subject: [PATCH 205/352] x86: Convert mce timer to hrtimer
mce_timer is started in atomic contexts of cpu bringup. This results
in might_sleep() warnings on RT. Convert mce_timer to a hrtimer to
avoid this.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
fold in:
|From: Mike Galbraith <bitbucket@online.de>
|Date: Wed, 29 May 2013 13:52:13 +0200
|Subject: [PATCH] x86/mce: fix mce timer interval
|
|Seems mce timer fire at the wrong frequency in -rt kernels since roughly
|forever due to 32 bit overflow. 3.8-rt is also missing a multiplier.
|
|Add missing us -> ns conversion and 32 bit overflow prevention.
|
|Signed-off-by: Mike Galbraith <bitbucket@online.de>
|[bigeasy: use ULL instead of u64 cast]
|Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
arch/x86/kernel/cpu/mcheck/mce.c | 52 ++++++++++++++++------------------------
1 file changed, 20 insertions(+), 32 deletions(-)
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 7e6163c..d8febf3 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -41,6 +41,7 @@
#include <linux/debugfs.h>
#include <linux/irq_work.h>
#include <linux/export.h>
+#include <linux/jiffies.h>
#include <linux/jump_label.h>
#include <asm/processor.h>
@@ -1335,7 +1336,7 @@ void mce_log_therm_throt_event(__u64 status)
static unsigned long check_interval = INITIAL_CHECK_INTERVAL;
static DEFINE_PER_CPU(unsigned long, mce_next_interval); /* in jiffies */
-static DEFINE_PER_CPU(struct timer_list, mce_timer);
+static DEFINE_PER_CPU(struct hrtimer, mce_timer);
static unsigned long mce_adjust_timer_default(unsigned long interval)
{
@@ -1344,32 +1345,18 @@ static unsigned long mce_adjust_timer_default(unsigned long interval)
static unsigned long (*mce_adjust_timer)(unsigned long interval) = mce_adjust_timer_default;
-static void __restart_timer(struct timer_list *t, unsigned long interval)
+static enum hrtimer_restart __restart_timer(struct hrtimer *timer, unsigned long interval)
{
- unsigned long when = jiffies + interval;
- unsigned long flags;
-
- local_irq_save(flags);
-
- if (timer_pending(t)) {
- if (time_before(when, t->expires))
- mod_timer(t, when);
- } else {
- t->expires = round_jiffies(when);
- add_timer_on(t, smp_processor_id());
- }
-
- local_irq_restore(flags);
+ if (!interval)
+ return HRTIMER_NORESTART;
+ hrtimer_forward_now(timer, ns_to_ktime(jiffies_to_nsecs(interval)));
+ return HRTIMER_RESTART;
}
-static void mce_timer_fn(unsigned long data)
+static enum hrtimer_restart mce_timer_fn(struct hrtimer *timer)
{
- struct timer_list *t = this_cpu_ptr(&mce_timer);
- int cpu = smp_processor_id();
unsigned long iv;
- WARN_ON(cpu != data);
-
iv = __this_cpu_read(mce_next_interval);
if (mce_available(this_cpu_ptr(&cpu_info))) {
@@ -1392,7 +1379,7 @@ static void mce_timer_fn(unsigned long data)
done:
__this_cpu_write(mce_next_interval, iv);
- __restart_timer(t, iv);
+ return __restart_timer(timer, iv);
}
/*
@@ -1400,7 +1387,7 @@ static void mce_timer_fn(unsigned long data)
*/
void mce_timer_kick(unsigned long interval)
{
- struct timer_list *t = this_cpu_ptr(&mce_timer);
+ struct hrtimer *t = this_cpu_ptr(&mce_timer);
unsigned long iv = __this_cpu_read(mce_next_interval);
__restart_timer(t, interval);
@@ -1415,7 +1402,7 @@ static void mce_timer_delete_all(void)
int cpu;
for_each_online_cpu(cpu)
- del_timer_sync(&per_cpu(mce_timer, cpu));
+ hrtimer_cancel(&per_cpu(mce_timer, cpu));
}
static void mce_do_trigger(struct work_struct *work)
@@ -1755,7 +1742,7 @@ static void __mcheck_cpu_clear_vendor(struct cpuinfo_x86 *c)
}
}
-static void mce_start_timer(unsigned int cpu, struct timer_list *t)
+static void mce_start_timer(unsigned int cpu, struct hrtimer *t)
{
unsigned long iv = check_interval * HZ;
@@ -1764,16 +1751,17 @@ static void mce_start_timer(unsigned int cpu, struct timer_list *t)
per_cpu(mce_next_interval, cpu) = iv;
- t->expires = round_jiffies(jiffies + iv);
- add_timer_on(t, cpu);
+ hrtimer_start_range_ns(t, ns_to_ktime(jiffies_to_usecs(iv) * 1000ULL),
+ 0, HRTIMER_MODE_REL_PINNED);
}
static void __mcheck_cpu_init_timer(void)
{
- struct timer_list *t = this_cpu_ptr(&mce_timer);
+ struct hrtimer *t = this_cpu_ptr(&mce_timer);
unsigned int cpu = smp_processor_id();
- setup_pinned_timer(t, mce_timer_fn, cpu);
+ hrtimer_init(t, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ t->function = mce_timer_fn;
mce_start_timer(cpu, t);
}
@@ -2518,6 +2506,8 @@ static void mce_disable_cpu(void *h)
if (!mce_available(raw_cpu_ptr(&cpu_info)))
return;
+ hrtimer_cancel(this_cpu_ptr(&mce_timer));
+
if (!(action & CPU_TASKS_FROZEN))
cmci_clear();
@@ -2540,6 +2530,7 @@ static void mce_reenable_cpu(void *h)
if (b->init)
wrmsrl(msr_ops.ctl(i), b->ctl);
}
+ __mcheck_cpu_init_timer();
}
/* Get notified when a cpu comes on/off. Be hotplug friendly. */
@@ -2547,7 +2538,6 @@ static int
mce_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
{
unsigned int cpu = (unsigned long)hcpu;
- struct timer_list *t = &per_cpu(mce_timer, cpu);
switch (action & ~CPU_TASKS_FROZEN) {
case CPU_ONLINE:
@@ -2567,11 +2557,9 @@ mce_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
break;
case CPU_DOWN_PREPARE:
smp_call_function_single(cpu, mce_disable_cpu, &action, 1);
- del_timer_sync(t);
break;
case CPU_DOWN_FAILED:
smp_call_function_single(cpu, mce_reenable_cpu, &action, 1);
- mce_start_timer(cpu, t);
break;
}
--
2.7.4
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