On 12 August 2014 17:03, Prarit Bhargava <[email protected]> wrote: > Okay, this is what I have and I can reproduce this *easily* 100% of the time. > > I've used your above config options and have enabled LOCKDEP. > > In order to restore the locking, I've applied the following patch to the > cpufreq > core (sorry for the cut-and-paste): > > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c > index d9fdedd..dfda238 100644 > --- a/drivers/cpufreq/cpufreq.c > +++ b/drivers/cpufreq/cpufreq.c > @@ -2192,9 +2192,7 @@ static int cpufreq_set_policy(struct cpufreq_policy > *polic > /* end old governor */ > if (old_gov) { > __cpufreq_governor(policy, CPUFREQ_GOV_STOP); > - up_write(&policy->rwsem); > __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT); > - down_write(&policy->rwsem); > } > > /* start new governor */ > @@ -2203,9 +2201,7 @@ static int cpufreq_set_policy(struct cpufreq_policy > *polic > if (!__cpufreq_governor(policy, CPUFREQ_GOV_START)) > goto out; > > - up_write(&policy->rwsem); > __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT); > - down_write(&policy->rwsem); > } > > /* new governor failed, so re-start old one */ > > > I've modified the acpi-cpufreq driver to include (sorry for the cut-and-paste) > > diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c > index b0c18ed..97653c3 100644 > --- a/drivers/cpufreq/acpi-cpufreq.c > +++ b/drivers/cpufreq/acpi-cpufreq.c > @@ -884,6 +884,9 @@ static struct freq_attr *acpi_cpufreq_attr[] = { > }; > > static struct cpufreq_driver acpi_cpufreq_driver = { > + .flags = CPUFREQ_STICKY | > + CPUFREQ_HAVE_GOVERNOR_PER_POLICY | > + CPUFREQ_NEED_INITIAL_FREQ_CHECK, > .verify = cpufreq_generic_frequency_table_verify, > .target_index = acpi_cpufreq_target, > .bios_limit = acpi_processor_get_bios_limit, > > I do a > > cat /sys/devices/system/cpu/cpu2/cpufreq/conservative/* > echo ondemand > /sys/devices/system/cpu/cpu2/cpufreq/scaling_governor > > and then I immediately see the stack trace.
What's your system configuration? How many clusters/cpus/etc.. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
