linux-kernel - Re: [PATCH v2.1 4/4] cpufreq: schedutil: Always call driver if need_freq

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20201028035702.75f6rnbkvfaic4si@vireshk-i7>
Date:   Wed, 28 Oct 2020 09:27:02 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     "Rafael J. Wysocki" <rjw@...ysocki.net>
Cc:     Linux PM <linux-pm@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>,
        Zhang Rui <rui.zhang@...el.com>
Subject: Re: [PATCH v2.1 4/4] cpufreq: schedutil: Always call driver if
 need_freq_update is set

On 27-10-20, 16:35, Rafael J. Wysocki wrote:
> Index: linux-pm/kernel/sched/cpufreq_schedutil.c
> ===================================================================
> --- linux-pm.orig/kernel/sched/cpufreq_schedutil.c
> +++ linux-pm/kernel/sched/cpufreq_schedutil.c
> @@ -102,11 +102,12 @@ static bool sugov_should_update_freq(str
>  static bool sugov_update_next_freq(struct sugov_policy *sg_policy, u64 time,
>  				   unsigned int next_freq)
>  {
> -	if (sg_policy->next_freq == next_freq)
> +	if (sg_policy->next_freq == next_freq && !sg_policy->need_freq_update)
>  		return false;
>  
>  	sg_policy->next_freq = next_freq;
>  	sg_policy->last_freq_update_time = time;
> +	sg_policy->need_freq_update = false;
>  
>  	return true;
>  }
> @@ -161,10 +162,12 @@ static unsigned int get_next_freq(struct
>  
>  	freq = map_util_freq(util, freq, max);
>  
> -	if (freq == sg_policy->cached_raw_freq && !sg_policy->need_freq_update)
> +	if (cpufreq_driver_test_flags(CPUFREQ_NEED_UPDATE_LIMITS))
> +		sg_policy->need_freq_update = true;
> +	else if (freq == sg_policy->cached_raw_freq &&
> +		 !sg_policy->need_freq_update)
>  		return sg_policy->next_freq;
>  
> -	sg_policy->need_freq_update = false;
>  	sg_policy->cached_raw_freq = freq;
>  	return cpufreq_driver_resolve_freq(policy, freq);
>  }

What about just this instead ?

  static bool sugov_update_next_freq(struct sugov_policy *sg_policy, u64 time,
  				   unsigned int next_freq)
  {
 -	if (sg_policy->next_freq == next_freq)
 +	if (sg_policy->next_freq == next_freq &&
 +          !cpufreq_driver_test_flags(CPUFREQ_NEED_UPDATE_LIMITS))
  		return false;
  
  	sg_policy->next_freq = next_freq;
  	sg_policy->last_freq_update_time = time;
  
  	return true;
  }

-- 
viresh