Re: [PATCH] cpufreq: create per policy rwsem instead of per cpu cpu_policy_rwsem

[Viresh Kumar]

On 18 September 2013 12:39, Srivatsa S. Bhat
<srivatsa.bhat@xxxxxxxxxxxxxxxxxx> wrote:
> On 09/17/2013 09:20 PM, Viresh Kumar wrote:

> The code looks good, but the patch doesn't apply properly, because of the code
> change that went in in your patch "cpufreq: Clear policy->cpus bits in
> __cpufreq_remove_dev_finish()".

Hmm.. Because of the number of patches floating now a days, it is getting more
and more complex..

I will sort things out once Rafael starts picking stuff for 3.13..

>> diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h

>> +     /*
>> +      * The rules for this semaphore:
>> +      * - Any routine that wants to read from the policy structure will
>> +      *   do a down_read on this semaphore.
>> +      * - Any routine that will write to the policy structure and/or may take away
>> +      *   the policy altogether (eg. CPU hotplug), will hold this lock in write
>> +      *   mode before doing so.
>> +      *
>> +      * Additional rules:
>> +      * - Governor routines that can be called in cpufreq hotplug path should not
>> +      *   take this sem as top level hotplug notifier handler takes this.
>
> I think this comment is obsolete. I don't see the top-level hotplug notifier handler
> (cpufreq_cpu_callback) acquiring the rwsem. Good to fix this comment while we are
> at it, perhaps in a separate patch. (The comment above __cpufreq_remove_dev about
> the policy-rwsem appears to be similarly out of date).

Yeah.. Will get that done, but will send these again only once Rafael is picking
stuff for 3.13..
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/