Re: [PATCH 2/2] cpufreq: don't call cpufreq_update_policy() on CPU addition

From: Rafael J. Wysocki
Date: Sun Feb 16 2014 - 19:07:52 EST


On Friday, February 14, 2014 04:30:41 PM Viresh Kumar wrote:
> cpufreq_update_policy() is called from two places currently. From a workqueue
> handled queued from cpufreq_bp_resume() for boot CPU and from
> cpufreq_cpu_callback() whenever a CPU is added.
>
> The first one makes sure that boot CPU is running on the frequency present in
> policy->cpu. But we don't really need a call from cpufreq_cpu_callback(),
> because we always call cpufreq_driver->init() (which will set policy->cur
> correctly) whenever first CPU of any policy is added back. And so every policy
> structure is guaranteed to have the right frequency in policy->cur.

That sounds good, but doing the extra cpufreq_update_policy() shouldn't actually
hurt, should it?

So, that would be a cleanup rather than a fix, right?

> Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
> ---
> drivers/cpufreq/cpufreq.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> index 383362b..b6eb4ed 100644
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -2194,7 +2194,6 @@ static int cpufreq_cpu_callback(struct notifier_block *nfb,
> switch (action & ~CPU_TASKS_FROZEN) {
> case CPU_ONLINE:
> __cpufreq_add_dev(dev, NULL, frozen);
> - cpufreq_update_policy(cpu);
> break;
>
> case CPU_DOWN_PREPARE:
>

--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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