linux-kernel - Re: [PATCH V3 8/9] cpufreq: Keep policy->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 for Android: free password hash cracker in your pocket

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

Message-ID: <20160603234854.GF14579@graphite.smuckle.net>
Date:	Fri, 3 Jun 2016 16:48:54 -0700
From:	Steve Muckle <steve.muckle@...aro.org>
To:	Viresh Kumar <viresh.kumar@...aro.org>
Cc:	Rafael Wysocki <rjw@...ysocki.net>,
	Benjamin Herrenschmidt <benh@...nel.crashing.org>,
	Paul Mackerras <paulus@...ba.org>,
	Michael Ellerman <mpe@...erman.id.au>,
	linaro-kernel@...ts.linaro.org, linux-pm@...r.kernel.org,
	linux-kernel@...r.kernel.org, steve.muckle@...aro.org,
	linuxppc-dev@...ts.ozlabs.org,
	Dmitry Eremin-Solenikov <dbaryshkov@...il.com>,
	Krzysztof Kozlowski <k.kozlowski@...sung.com>,
	Kukjin Kim <kgene@...nel.org>,
	Shawn Guo <shawn.guo@...escale.com>,
	Steven Miao <realmz6@...il.com>
Subject: Re: [PATCH V3 8/9] cpufreq: Keep policy->freq_table sorted in
 ascending order

On Fri, Jun 03, 2016 at 07:05:14PM +0530, Viresh Kumar wrote:
...
> @@ -468,20 +469,15 @@ unsigned int acpi_cpufreq_fast_switch(struct cpufreq_policy *policy,
>  	struct acpi_cpufreq_data *data = policy->driver_data;
>  	struct acpi_processor_performance *perf;
>  	struct cpufreq_frequency_table *entry;
> -	unsigned int next_perf_state, next_freq, freq;
> +	unsigned int next_perf_state, next_freq, index;
>  
>  	/*
>  	 * Find the closest frequency above target_freq.
> -	 *
> -	 * The table is sorted in the reverse order with respect to the
> -	 * frequency and all of the entries are valid (see the initialization).
>  	 */
> -	entry = policy->freq_table;
> -	do {
> -		entry++;
> -		freq = entry->frequency;
> -	} while (freq >= target_freq && freq != CPUFREQ_TABLE_END);
> -	entry--;
> +	index = cpufreq_frequency_table_target(policy, target_freq,
> +					       CPUFREQ_RELATION_L);

Can we call cpufreq_find_index_l directly here? Seems like we could
phase out cpufreq_frequency_table_target() for the most part and call
the helpers directly. It would avoid some code bloat, an unnecessary
switch statement and an error check for an invalid frequency table which
seems unnecessary for every frequency table lookup.

thanks,
Steve