On 19. 7. 19. 오전 9:42, Dmitry Osipenko wrote:
> В Thu, 18 Jul 2019 18:48:42 +0900
> Chanwoo Choi <[email protected]> пишет:
> 
>> On 19. 7. 8. 오전 7:32, Dmitry Osipenko wrote:
>>> When CPU's memory activity is low or memory activity is high such
>>> that CPU's frequency contribution to the boosting is not taken into
>>> account, then there is no need to schedule devfreq's update. This
>>> eliminates unnecessary CPU activity during of idling caused by the
>>> scheduled work.
>>>
>>> Signed-off-by: Dmitry Osipenko <[email protected]>
>>> ---
>>>  drivers/devfreq/tegra30-devfreq.c | 73
>>> +++++++++++++++++++++++++++---- 1 file changed, 64 insertions(+), 9
>>> deletions(-)  
>>
>> Patch4 add the 'cpufreq notifier' and this patch optimize the cpufreq
>> notifier. I think t hat you can combine two patches.
> 
> I'd prefer to keep them separate for a sake of git bisection.

Sorry, patch7 instead of patch4.

Patch7 made the 'tegra_actmon_cpu_notify_cb()' function
and this patch makes 'tegra_actmon_cpufreq_contribution' function
which is only called in the 'tegra_actmon_cpu_notify_cb()' function.

It is enough to make them as the only one patch related to
the cpu notifier. As I replied on patch17, you can merge
the patch if the patches has some relationship in this patchset.

> 
>>>
>>> diff --git a/drivers/devfreq/tegra30-devfreq.c
>>> b/drivers/devfreq/tegra30-devfreq.c index
>>> 43c9c5fbfe91..8d6bf6e9f1ae 100644 ---
>>> a/drivers/devfreq/tegra30-devfreq.c +++
>>> b/drivers/devfreq/tegra30-devfreq.c @@ -216,10 +216,10 @@ static
>>> inline unsigned long do_percent(unsigned long val, unsigned int
>>> pct) return val * pct / 100; }
>>>  
>>> -static unsigned long actmon_cpu_to_emc_rate(struct tegra_devfreq
>>> *tegra) +static unsigned long actmon_cpu_to_emc_rate(struct
>>> tegra_devfreq *tegra,
>>> +                                       unsigned int cpu_freq)
>>>  {
>>>     const struct tegra_actmon_emc_ratio *ratio =
>>> actmon_emc_ratios;
>>> -   unsigned int cpu_freq = cpufreq_get(0);
>>>     unsigned int i;
>>>  
>>>     for (i = 0; i < ARRAY_SIZE(actmon_emc_ratios); i++,
>>> ratio++) { @@ -239,15 +239,15 @@
>>> tegra_actmon_account_cpu_freq(struct tegra_devfreq *tegra, struct
>>> tegra_devfreq_device *dev, unsigned long target_freq)
>>>  {
>>> -   unsigned long static_cpu_emc_freq;
>>> +   unsigned long cpu_emc_freq = 0;
>>>  
>>> -   if (dev->config->avg_dependency_threshold &&
>>> -       dev->config->avg_dependency_threshold < dev->avg_freq)
>>> {
>>> -           static_cpu_emc_freq =
>>> actmon_cpu_to_emc_rate(tegra);
>>> -           target_freq = max(target_freq,
>>> static_cpu_emc_freq);
>>> -   }
>>> +   if (!dev->config->avg_dependency_threshold)
>>> +           return target_freq;
>>>  
>>> -   return target_freq;
>>> +   if (dev->avg_freq > dev->config->avg_dependency_threshold)
>>> +           cpu_emc_freq = actmon_cpu_to_emc_rate(tegra,
>>> cpufreq_get(0)); +
>>> +   return max(target_freq, cpu_emc_freq);
>>>  }
>>>  
>>>  static unsigned long tegra_actmon_lower_freq(struct tegra_devfreq
>>> *tegra, @@ -531,16 +531,71 @@ static void
>>> tegra_actmon_delayed_update(struct work_struct *work)
>>> mutex_unlock(&tegra->devfreq->lock); }
>>>  
>>> +static unsigned long
>>> +tegra_actmon_cpufreq_contribution(struct tegra_devfreq *tegra,
>>> +                             unsigned int cpu_freq)
>>> +{
>>> +   unsigned long freq, static_cpu_emc_freq;
>>> +
>>> +   /* check whether CPU's freq is taken into account at all */
>>> +   if (tegra->devices[MCCPU].avg_freq <=
>>> +       tegra->devices[MCCPU].config->avg_dependency_threshold)
>>> +           return 0;
>>> +
>>> +   static_cpu_emc_freq = actmon_cpu_to_emc_rate(tegra,
>>> cpu_freq); +
>>> +   /* compare static CPU-EMC freq with MCALL */
>>> +   freq = tegra->devices[MCALL].avg_freq +
>>> +          tegra->devices[MCALL].boost_freq;
>>> +
>>> +   freq = tegra_actmon_upper_freq(tegra, freq);
>>> +
>>> +   if (freq == tegra->max_freq || freq >= static_cpu_emc_freq)
>>> +           return 0;
>>> +
>>> +   /* compare static CPU-EMC freq with MCCPU */
>>> +   freq = tegra->devices[MCCPU].avg_freq +
>>> +          tegra->devices[MCCPU].boost_freq;
>>> +
>>> +   freq = tegra_actmon_upper_freq(tegra, freq);
>>> +
>>> +   if (freq == tegra->max_freq || freq >= static_cpu_emc_freq)
>>> +           return 0;
>>> +
>>> +   return static_cpu_emc_freq;
>>> +}
>>> +
>>>  static int tegra_actmon_cpu_notify_cb(struct notifier_block *nb,
>>>                                   unsigned long action, void
>>> *ptr) {
>>> +   struct cpufreq_freqs *freqs = ptr;
>>>     struct tegra_devfreq *tegra;
>>> +   unsigned long old, new;
>>>  
>>>     if (action != CPUFREQ_POSTCHANGE)
>>>             return NOTIFY_OK;
>>>  
>>>     tegra = container_of(nb, struct tegra_devfreq,
>>> cpu_rate_change_nb); 
>>> +   /*
>>> +    * Quickly check whether CPU frequency should be taken
>>> into account
>>> +    * at all, without blocking CPUFreq's core.
>>> +    */
>>> +   if (mutex_trylock(&tegra->devfreq->lock)) {
>>> +           old = tegra_actmon_cpufreq_contribution(tegra,
>>> freqs->old);
>>> +           new = tegra_actmon_cpufreq_contribution(tegra,
>>> freqs->new);
>>> +           mutex_unlock(&tegra->devfreq->lock);
>>> +
>>> +           /*
>>> +            * If CPU's frequency shouldn't be taken into
>>> account at
>>> +            * the moment, then there is no need to update the
>>> devfreq's
>>> +            * state because ISR will re-check CPU's frequency
>>> on the
>>> +            * next interrupt.
>>> +            */
>>> +           if (old == new)
>>> +                   return NOTIFY_OK;
>>> +   }
>>> +
>>>     /*
>>>      * CPUFreq driver should support
>>> CPUFREQ_ASYNC_NOTIFICATION in order
>>>      * to allow asynchronous notifications. This means we
>>> can't block 
>>
>>
> 
> 
> 


-- 
Best Regards,
Chanwoo Choi
Samsung Electronics

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