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Re: [PATCH v2 12/12] cpufreq: governor: Narrow down the dbs_data_mutex coverage

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On 18-02-16, 18:58, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> Subject: [PATCH] cpufreq: governor: Narrow down the dbs_data_mutex coverage
> 
> Since cpufreq_governor_dbs() is now always called with policy->rwsem
> held, it cannot be executed twice in parallel for the same policy.
> Thus it is not necessary to hold dbs_data_mutex around the invocations
> of cpufreq_governor_start/stop/limits() from it as those functions
> never modify any data that can be shared between different policies.
> 
> However, cpufreq_governor_dbs() may be executed twice in parallal
> for different policies using the same gov->gdbs_data object and
> dbs_data_mutex is still necessary to protect that object against
> concurrent updates.
> 
> For this reason, narrow down the dbs_data_mutex locking to
> cpufreq_governor_init/exit() where it is needed and rename the
> mutex to gov_dbs_data_mutex to reflect its purpose.
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
>  drivers/cpufreq/cpufreq_governor.c |   46 ++++++++++++++++++-------------------
>  1 file changed, 23 insertions(+), 23 deletions(-)

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

-- 
viresh

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[PATCH 0/12] cpufreq: More governor code reorganization "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-02-18 02:40 +0100
  [PATCH 11/12] cpufreq: governor: Make dbs_data_mutex static "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-02-18 02:50 +0100
    Re: [PATCH 11/12] cpufreq: governor: Make dbs_data_mutex static Viresh Kumar <viresh.kumar@linaro.org> - 2016-02-18 07:10 +0100
  [PATCH 4/12] cpufreq: governor: Drop unused governor callback and data fields "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-02-18 02:50 +0100
    Re: [PATCH 4/12] cpufreq: governor: Drop unused governor callback  and data fields Viresh Kumar <viresh.kumar@linaro.org> - 2016-02-18 06:40 +0100
  [PATCH 5/12] cpufreq: ondemand: Drop one more callback from struct od_ops "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-02-18 02:50 +0100
    Re: [PATCH 5/12] cpufreq: ondemand: Drop one more callback from  struct od_ops Viresh Kumar <viresh.kumar@linaro.org> - 2016-02-18 06:40 +0100
  [PATCH 8/12] cpufreq: governor: Make governor private data per-policy "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-02-18 02:50 +0100
    Re: [PATCH 8/12] cpufreq: governor: Make governor private data  per-policy Viresh Kumar <viresh.kumar@linaro.org> - 2016-02-18 07:10 +0100
      [PATCH v2 8/12] cpufreq: governor: Make governor private data per-policy "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-02-18 19:00 +0100
        Re: [PATCH v2 8/12] cpufreq: governor: Make governor private data  per-policy Viresh Kumar <viresh.kumar@linaro.org> - 2016-02-19 03:40 +0100
  [PATCH 6/12] cpufreq: governor: Fix CPU load information updates via ->store "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-02-18 02:50 +0100
    Re: [PATCH 6/12] cpufreq: governor: Fix CPU load information updates  via ->store Viresh Kumar <viresh.kumar@linaro.org> - 2016-02-18 06:50 +0100
      Re: [PATCH 6/12] cpufreq: governor: Fix CPU load information updates  via ->store "Rafael J. Wysocki" <rafael@kernel.org> - 2016-02-18 18:40 +0100
  [PATCH 7/12] cpufreq: ondemand: Rework the handling of powersave bias updates "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-02-18 02:50 +0100
    Re: [PATCH 7/12] cpufreq: ondemand: Rework the handling of powersave  bias updates Viresh Kumar <viresh.kumar@linaro.org> - 2016-02-18 07:00 +0100
  [PATCH 12/12] cpufreq: governor: Narrow down the dbs_data_mutex coverage "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-02-18 02:50 +0100
    Re: [PATCH 12/12] cpufreq: governor: Narrow down the dbs_data_mutex  coverage Viresh Kumar <viresh.kumar@linaro.org> - 2016-02-18 07:30 +0100
      Re: [PATCH 12/12] cpufreq: governor: Narrow down the dbs_data_mutex coverage "Rafael J. Wysocki" <rafael@kernel.org> - 2016-02-18 17:40 +0100
      [PATCH v2 12/12] cpufreq: governor: Narrow down the dbs_data_mutex coverage "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-02-18 19:00 +0100
        Re: [PATCH v2 12/12] cpufreq: governor: Narrow down the  dbs_data_mutex coverage Viresh Kumar <viresh.kumar@linaro.org> - 2016-02-19 03:40 +0100

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