linux-kernel - Re: [PATCH v2 1/4] cpufreq: Introduce governor flags

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: <20201110024126.v4yxai5hpguj5p5b@vireshk-i7>
Date:   Tue, 10 Nov 2020 08:11:26 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     "Rafael J. Wysocki" <rjw@...ysocki.net>
Cc:     Linux PM <linux-pm@...r.kernel.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>,
        Zhang Rui <rui.zhang@...el.com>,
        LKML <linux-kernel@...r.kernel.org>,
        Doug Smythies <dsmythies@...us.net>
Subject: Re: [PATCH v2 1/4] cpufreq: Introduce governor flags

On 09-11-20, 17:51, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> 
> A new cpufreq governor flag will be added subsequently, so replace
> the bool dynamic_switching fleid in struct cpufreq_governor with a
> flags field and introduce CPUFREQ_GOV_FLAG_DYN_SWITCH to set for
> the "dynamic switching" governors instead of it.
> 
> No intentional functional impact.
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> ---
>  drivers/cpufreq/cpufreq.c          |    2 +-
>  drivers/cpufreq/cpufreq_governor.h |    2 +-
>  include/linux/cpufreq.h            |    9 +++++++--
>  kernel/sched/cpufreq_schedutil.c   |    2 +-
>  4 files changed, 10 insertions(+), 5 deletions(-)
> 
> Index: linux-pm/drivers/cpufreq/cpufreq.c
> ===================================================================
> --- linux-pm.orig/drivers/cpufreq/cpufreq.c
> +++ linux-pm/drivers/cpufreq/cpufreq.c
> @@ -2254,7 +2254,7 @@ static int cpufreq_init_governor(struct
>  		return -EINVAL;
>  
>  	/* Platform doesn't want dynamic frequency switching ? */
> -	if (policy->governor->dynamic_switching &&

I completely forgot that we had something like this :)

> +	if (policy->governor->flags & CPUFREQ_GOV_FLAG_DYN_SWITCH &&
>  	    cpufreq_driver->flags & CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING) {
>  		struct cpufreq_governor *gov = cpufreq_fallback_governor();
>  
> Index: linux-pm/drivers/cpufreq/cpufreq_governor.h
> ===================================================================
> --- linux-pm.orig/drivers/cpufreq/cpufreq_governor.h
> +++ linux-pm/drivers/cpufreq/cpufreq_governor.h
> @@ -156,7 +156,7 @@ void cpufreq_dbs_governor_limits(struct
>  #define CPUFREQ_DBS_GOVERNOR_INITIALIZER(_name_)			\
>  	{								\
>  		.name = _name_,						\
> -		.dynamic_switching = true,				\
> +		.flags = CPUFREQ_GOV_FLAG_DYN_SWITCH,			\
>  		.owner = THIS_MODULE,					\
>  		.init = cpufreq_dbs_governor_init,			\
>  		.exit = cpufreq_dbs_governor_exit,			\
> Index: linux-pm/include/linux/cpufreq.h
> ===================================================================
> --- linux-pm.orig/include/linux/cpufreq.h
> +++ linux-pm/include/linux/cpufreq.h
> @@ -565,12 +565,17 @@ struct cpufreq_governor {
>  					 char *buf);
>  	int	(*store_setspeed)	(struct cpufreq_policy *policy,
>  					 unsigned int freq);
> -	/* For governors which change frequency dynamically by themselves */
> -	bool			dynamic_switching;
>  	struct list_head	governor_list;
>  	struct module		*owner;
> +	u8			flags;
>  };
>  
> +/* Governor flags */
> +
> +/* For governors which change frequency dynamically by themselves */
> +#define CPUFREQ_GOV_FLAG_DYN_SWITCH	BIT(0)

Maybe just drop the FLAG_ part as we don't use it for other cpufreq related
flags as well. That will also give us space to write DYN as DYNAMIC (it may be
better as we use the full name in CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING).

Acked-by: Viresh Kumar <viresh.kumar@...aro.org>

-- 
viresh