Re: [PATCH v6 2/2] cpufreq: covert the cpufreq_data_lock to a spinlock

From: Rafael J. Wysocki
Date: Tue Apr 02 2013 - 08:40:36 EST


On Tuesday, April 02, 2013 10:34:21 AM Viresh Kumar wrote:
> On 2 April 2013 06:26, Nathan Zimmer <nzimmer@xxxxxxx> wrote:
> > On Mon, Apr 01, 2013 at 10:41:27PM +0200, Rafael J. Wysocki wrote:
> >> On Monday, April 01, 2013 03:11:09 PM Nathan Zimmer wrote:
> >> > This eliminates the rest of the contention found in __cpufreq_cpu_get.
> >> > I am not seeing a way to use the rcu so we will have to make due with a
> >> > rwlock for now.
> >> >
> >> > Cc: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
> >> > Cc: "Rafael J. Wysocki" <rjw@xxxxxxx>
> >> > Signed-off-by: Nathan Zimmer <nzimmer@xxxxxxx>
> >>
> >> I've already applied this one.
> >>
> >> Can you please check if the version in my tree is OK?
> >>
> >> Rafael
> >>
> >
> > Nope, the previous version was too different, probably best to just replace it.
>
> Nathan,
>
> First of all I should accept that I didn't had your last patch while
> reviewing this
> one earlier. Thanks Rafael.
>
> Now, I believe the previous patch which Rafael has pushed was good and we
> can simply keep it. What you can do is, just add a patch over it (which would
> mostly be 1/2 of your patchset), that simply separates rcu stuff out of the lock
> and leave lock for cpufreq_data..

Yeah, I'd very much prefer that.

Nathan, I'm going to keep the rwlock patch unless it is demonstrably incorrect.

Thanks,
Rafael


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