From 539a0a5991dfe1a702ff89fe962be0c8288f2392 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 13 Dec 2010 16:33:39 +0100 Subject: [PATCH 203/365] 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 fold in: |From: Mike Galbraith |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 |[bigeasy: use ULL instead of u64 cast] |Signed-off-by: Sebastian Andrzej Siewior --- 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 07188a012492..6af5d3590271 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -41,6 +41,7 @@ #include #include #include +#include #include #include @@ -1368,7 +1369,7 @@ 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) { @@ -1377,32 +1378,18 @@ 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))) { @@ -1425,7 +1412,7 @@ 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); } /* @@ -1433,7 +1420,7 @@ 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); @@ -1448,7 +1435,7 @@ 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) @@ -1758,7 +1745,7 @@ 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; @@ -1767,16 +1754,17 @@ 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); } @@ -2521,6 +2509,8 @@ 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(); @@ -2543,6 +2533,7 @@ 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. */ @@ -2550,7 +2541,6 @@ 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: @@ -2570,11 +2560,9 @@ 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; } -- 2.28.0