Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1220443

Re: [PATCH V2 2/9] cpufreq: conservative: remove 'enable' field

Show all headers | View raw

On 08-09-15, 02:17, Rafael J. Wysocki wrote:
> >  static inline unsigned int get_freq_target(struct cs_dbs_tuners *cs_tuners,
> >  					   struct cpufreq_policy *policy)
> >  {
> > @@ -119,12 +132,14 @@ static int dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
> >  	struct cpufreq_freqs *freq = data;
> >  	struct cs_cpu_dbs_info_s *dbs_info =
> >  					&per_cpu(cs_cpu_dbs_info, freq->cpu);
> > -	struct cpufreq_policy *policy;
> > +	struct cpufreq_policy *policy = cpufreq_cpu_get(freq->cpu);
> >  
> > -	if (!dbs_info->enable)
> > +	if (!policy)
> >  		return 0;
> >  
> > -	policy = dbs_info->cdbs.shared->policy;
> 
> So here we could get to the policy directly.  After the change we have to:
> 
> - acquire cpufreq_rwsem
> - acquire cpufreq_driver_lock
> - go the kobject_get on policy->kobj

Hmm, actually we can do cpufreq_cpu_get_raw() here as this is getting
called from notifier and policy isn't going to get freed for sure.

And then it wouldn't be that bad.

> and then finally drop the reference to the kobject when we're done.
> 
> So may I ask where exactly is the improvement?

Agree. Let me resend it quickly.

> > +	/* policy isn't governed by conservative governor */
> > +	if (policy->governor != &cpufreq_gov_conservative)
> > +		goto policy_put;
> >  
> >  	/*
> >  	 * we only care if our internally tracked freq moves outside the 'valid'
> 
> Thanks,
> Rafael

-- 
viresh
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Re: [PATCH V2 2/9] cpufreq: conservative: remove 'enable' field "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2015-09-08 02:00 +0200
  Re: [PATCH V2 2/9] cpufreq: conservative: remove 'enable' field Viresh Kumar <viresh.kumar@linaro.org> - 2015-09-08 03:40 +0200
  [PATCH V3 2/9] cpufreq: conservative: remove 'enable' field Viresh Kumar <viresh.kumar@linaro.org> - 2015-09-08 03:50 +0200

csiph-web