linux-kernel - Re: [Update][PATCH] cpufreq: Do not hold driver module references for additional policy CPUs

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Message-ID: <51FB85F5.6060600@linux.vnet.ibm.com>
Date:	Fri, 02 Aug 2013 15:42:05 +0530
From:	"Srivatsa S. Bhat" <srivatsa.bhat@...ux.vnet.ibm.com>
To:	Viresh Kumar <viresh.kumar@...aro.org>
CC:	"Rafael J. Wysocki" <rjw@...k.pl>,
	Linux PM list <linux-pm@...r.kernel.org>,
	cpufreq@...r.kernel.org, LKML <linux-kernel@...r.kernel.org>,
	Lists linaro-kernel <linaro-kernel@...ts.linaro.org>
Subject: Re: [Update][PATCH] cpufreq: Do not hold driver module references
 for additional policy CPUs

On 08/02/2013 03:06 PM, Viresh Kumar wrote:
> On 2 August 2013 12:19, Srivatsa S. Bhat
> <srivatsa.bhat@...ux.vnet.ibm.com> wrote:
>> On 08/02/2013 10:07 AM, Viresh Kumar wrote:
>>> So, we can't rmmod the module as soon as it is inserted and so the
>>> problem stays as is. :(
>>>
>>
>> No, we get one step closer to the solution, since we fix the inconsistency
>> between refcounts. Next step would be to get rid of refcounts and use
>> locking like you suggested. Then we can rmmod it easily. I'm assuming
>> Rafael has the same plan.
> 
> Not really. We are putting the reference at the end of add_dev() and
> so refcount would be zero when we aren't running any critical sections.
> And so, we can rmmod the module now and that problem is gone.
> 

Ah, yes, you are right.

> @Rafael: I will try to do generic cleanups in cpufreq in coming time
> and will take care to remove .owner field completely in that. Until that
> point your patches look fine:
> 
> For both of your patches:
> Acked-by: Viresh Kumar <viresh.kumar@...aro.org>
> 
 
Regards,
Srivatsa S. Bhat

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