On Thu, 2024-09-19 at 10:11 +0200, Uwe Kleine-König wrote: > notify_hwp_interrupt() is called via sysvec_thermal() -> > smp_thermal_vector() -> intel_thermal_interrupt() in hard irq > context. > For this reason it must not use a simple spin_lock that sleeps with > PREEMPT_RT enabled. So convert it to a raw spinlock. > > Reported-by: xiao sheng wen <atzlinux@xxxxxxxx> > Link: https://bugs.debian.org/1076483 > Signed-off-by: Uwe Kleine-König <ukleinek@xxxxxxxxxx> Missing Tested-by? Acked-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx> > --- > Hello, > > this is deep in x86 land where I have *very* little experience and > knowledge. Is sysvec_thermal() (defined in arch/x86/kernel/irq.c) > really > running in hard irq context? The stacktrace in the Debian bug report > suggests that. > > So please double check my reasoning before applying this patch. > This is thermal LVT and runs in hard IRQ context. > Thanks > Uwe > > drivers/cpufreq/intel_pstate.c | 16 ++++++++-------- > 1 file changed, 8 insertions(+), 8 deletions(-) > > diff --git a/drivers/cpufreq/intel_pstate.c > b/drivers/cpufreq/intel_pstate.c > index aaea9a39eced..b0018f371ea3 100644 > --- a/drivers/cpufreq/intel_pstate.c > +++ b/drivers/cpufreq/intel_pstate.c > @@ -1845,7 +1845,7 @@ static void intel_pstate_notify_work(struct > work_struct *work) > wrmsrl_on_cpu(cpudata->cpu, MSR_HWP_STATUS, 0); > } > > -static DEFINE_SPINLOCK(hwp_notify_lock); > +static DEFINE_RAW_SPINLOCK(hwp_notify_lock); > static cpumask_t hwp_intr_enable_mask; > > #define HWP_GUARANTEED_PERF_CHANGE_STATUS BIT(0) > @@ -1868,7 +1868,7 @@ void notify_hwp_interrupt(void) > if (!(value & status_mask)) > return; > > - spin_lock_irqsave(&hwp_notify_lock, flags); > + raw_spin_lock_irqsave(&hwp_notify_lock, flags); > > if (!cpumask_test_cpu(this_cpu, &hwp_intr_enable_mask)) > goto ack_intr; > @@ -1876,13 +1876,13 @@ void notify_hwp_interrupt(void) > schedule_delayed_work(&all_cpu_data[this_cpu]- > >hwp_notify_work, > msecs_to_jiffies(10)); > > - spin_unlock_irqrestore(&hwp_notify_lock, flags); > + raw_spin_unlock_irqrestore(&hwp_notify_lock, flags); > > return; > > ack_intr: > wrmsrl_safe(MSR_HWP_STATUS, 0); > - spin_unlock_irqrestore(&hwp_notify_lock, flags); > + raw_spin_unlock_irqrestore(&hwp_notify_lock, flags); > } > > static void intel_pstate_disable_hwp_interrupt(struct cpudata > *cpudata) > @@ -1895,9 +1895,9 @@ static void > intel_pstate_disable_hwp_interrupt(struct cpudata *cpudata) > /* wrmsrl_on_cpu has to be outside spinlock as this can > result in IPC */ > wrmsrl_on_cpu(cpudata->cpu, MSR_HWP_INTERRUPT, 0x00); > > - spin_lock_irq(&hwp_notify_lock); > + raw_spin_lock_irq(&hwp_notify_lock); > cancel_work = cpumask_test_and_clear_cpu(cpudata->cpu, > &hwp_intr_enable_mask); > - spin_unlock_irq(&hwp_notify_lock); > + raw_spin_unlock_irq(&hwp_notify_lock); > > if (cancel_work) > cancel_delayed_work_sync(&cpudata->hwp_notify_work); > @@ -1912,10 +1912,10 @@ static void > intel_pstate_enable_hwp_interrupt(struct cpudata *cpudata) > if (boot_cpu_has(X86_FEATURE_HWP_NOTIFY)) { > u64 interrupt_mask = HWP_GUARANTEED_PERF_CHANGE_REQ; > > - spin_lock_irq(&hwp_notify_lock); > + raw_spin_lock_irq(&hwp_notify_lock); > INIT_DELAYED_WORK(&cpudata->hwp_notify_work, > intel_pstate_notify_work); > cpumask_set_cpu(cpudata->cpu, > &hwp_intr_enable_mask); > - spin_unlock_irq(&hwp_notify_lock); > + raw_spin_unlock_irq(&hwp_notify_lock); > > if > (cpu_feature_enabled(X86_FEATURE_HWP_HIGHEST_PERF_CHANGE)) > interrupt_mask |= > HWP_HIGHEST_PERF_CHANGE_REQ; > > base-commit: 3621a2c9142bd490af0666c0c02d52d60ce0d2a5
