linux-kernel - Re: [PATCH 1/5] cpufreq: Use cpumask_copy instead of cpumask

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Message-ID: <20151013032301.GL5386@linux>
Date:	Tue, 13 Oct 2015 08:53:01 +0530
From:	Viresh Kumar <viresh.kumar@...aro.org>
To:	Saravana Kannan <skannan@...eaurora.org>
Cc:	Rafael Wysocki <rjw@...ysocki.net>, linaro-kernel@...ts.linaro.org,
	linux-pm@...r.kernel.org, open list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 1/5] cpufreq: Use cpumask_copy instead of cpumask_or to
 copy a mask

On 12-10-15, 12:12, Saravana Kannan wrote:
> >  	if (new_policy) {
> >  		/* related_cpus should at least include policy->cpus. */
> >-		cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus);
> >+		cpumask_copy(policy->related_cpus, policy->cpus);
> 
> Again, why? It actually seems wrong. A 4 core cluster could come up
> with just 2 cores when the policy is added. But the related CPUs
> would be 4 CPUs.

Firstly, the patch hasn't changed anything at all. related_cpus was
empty until this point, and orring or setting it with ->cpus will
result in the same output.

Secondly, this is what we always wanted. related_cpus should contain
the mask of all possible CPUs for that cluster.

-- 
viresh
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