Re: [PATCH 3/6 v4] cpufreq: tolerate inexact values when collecting stats

Mark Langsdorf
2012-11-26T13:56:43Z

On 11/24/2012 04:05 AM, Rafael J. Wysocki wrote:
> On Saturday, November 17, 2012 03:50:48 PM Borislav Petkov wrote:
>> On Tue, Nov 13, 2012 at 02:13:38PM -0500, Mark Langsdorf wrote:
>>> Although cpufreq_driver has a flag field, no part of cpufreq_driver
>>> is directly passed to the cpufreq_stat code. Only cpufreq_policy
>>> is. It's cleaner to do passes of the while loop than to copy the
>>> cpufreq_driver.flag field into cpufreq_policy and then store it again
>>> in cpufreq_stats.
>>
>> That maybe so but this newly added loop which is only Calxeda-relevant
>> is called in cpufreq_stat_notifier_trans, which is the frequency change
>> notifier call, AFAICT.

Drivers only go through the loop if they can't find an exact frequency.
So every driver that isn't Calxeda shouldn't see the issue.

>> So you probably need to find a slick way of detecting calxeda hw
>> somewhere along the init path of cpufreq_stats_init and set a
>> hw-specific flag instead of adding that cost to each driver.
>
> Mark, I suppose you'd like me to take this series for v3.8, but the above
> comment from Boris has to be addressed for that.

I think I'd rather drop this particular patch and not have cpufreq_stat
support for Highbank. Redesigning it to meet Boris' requirements is
going to take more time than I currently have available.

Would it be acceptable to drop this patch and fix the issues with
patches 4 and 6 to get the series in?

--Mark Langsdorf
Calxeda, Inc.