On 06/25/2013 10:19 AM, Jacob Shin wrote: > On Tue, Jun 25, 2013 at 12:26:14PM +0530, Viresh Kumar wrote: >> On 24 June 2013 22:29, Tim Gardner <[email protected]> wrote: >>> This is from Ubuntu Saucy based on 3.10-rc7: >>> >>> [ 12.911676] BUG: unable to handle kernel NULL pointer dereference at >>> 0000000000000070 >>> [ 12.911691] IP: [<ffffffff8156e572>] od_set_powersave_bias+0x92/0xc0 >>> >> >> Can you please look into this bug? It occurred after your >> patch... This is the boot log crash we have: > > Hi, > > Yes, so sorry about that, it looks like I failed to test with: > > CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE=y > CONFIG_CPU_FREQ_GOV_PERFORMANCE=y > CONFIG_CPU_FREQ_GOV_ONDEMAND=y > CONFIG_X86_AMD_FREQ_SENSITIVITY=m > > The following patch fixes this, Tim, could you please test ? : > > ---8<--- > > From 3c727b1f775448599e67c5fb2121d79448e80c90 Mon Sep 17 00:00:00 2001 > From: Jacob Shin <[email protected]> > Date: Tue, 25 Jun 2013 10:40:54 -0500 > Subject: [PATCH 1/1] cpufreq: fix NULL pointer deference at > od_set_powersave_bias() > > When initializing the default powersave_bias value, we need to first > make sure that this policy is running the ondemand governor. > > Reported-by: Tim Gardner <[email protected]> > Signed-off-by: Jacob Shin <[email protected]> > --- > drivers/cpufreq/cpufreq_ondemand.c | 17 +++++++++++++---- > 1 file changed, 13 insertions(+), 4 deletions(-) > > diff --git a/drivers/cpufreq/cpufreq_ondemand.c > b/drivers/cpufreq/cpufreq_ondemand.c > index 4b9bb5d..93eb5cb 100644 > --- a/drivers/cpufreq/cpufreq_ondemand.c > +++ b/drivers/cpufreq/cpufreq_ondemand.c > @@ -47,6 +47,8 @@ static struct od_ops od_ops; > static struct cpufreq_governor cpufreq_gov_ondemand; > #endif > > +static unsigned int default_powersave_bias; > + > static void ondemand_powersave_bias_init_cpu(int cpu) > { > struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, cpu); > @@ -543,7 +545,7 @@ static int od_init(struct dbs_data *dbs_data) > > tuners->sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR; > tuners->ignore_nice = 0; > - tuners->powersave_bias = 0; > + tuners->powersave_bias = default_powersave_bias; > tuners->io_is_busy = should_io_be_busy(); > > dbs_data->tuners = tuners; > @@ -585,6 +587,7 @@ static void od_set_powersave_bias(unsigned int > powersave_bias) > unsigned int cpu; > cpumask_t done; > > + default_powersave_bias = powersave_bias; > cpumask_clear(&done); > > get_online_cpus(); > @@ -593,11 +596,17 @@ static void od_set_powersave_bias(unsigned int > powersave_bias) > continue; > > policy = per_cpu(od_cpu_dbs_info, cpu).cdbs.cur_policy; > - dbs_data = policy->governor_data; > - od_tuners = dbs_data->tuners; > - od_tuners->powersave_bias = powersave_bias; > + if (!policy) > + continue; > > cpumask_or(&done, &done, policy->cpus); > + > + if (policy->governor != &cpufreq_gov_ondemand) > + continue; > + > + dbs_data = policy->governor_data; > + od_tuners = dbs_data->tuners; > + od_tuners->powersave_bias = default_powersave_bias; > } > put_online_cpus(); > } >
That appears to have done the trick. You can add my Tested-by. rtg -- Tim Gardner [email protected] -- 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/
