On Friday, February 05, 2016 12:23:41 PM Viresh Kumar wrote: > On 05-02-16, 03:14, Rafael J. Wysocki wrote: > > From: Rafael J. Wysocki <rafael.j.wyso...@intel.com> > > > > Every governor relying on the common code in cpufreq_governor.c > > has to provide its own mutex in struct common_dbs_data. However, > > there actually is no need to have a separate mutex per governor > > for this purpose, they may be using the same global mutex just > > fine. Accordingly, introduce a single common mutex for that and > > drop the mutex field from struct common_dbs_data. > > > > That at least will ensure that the mutex is always present and > > initialized regardless of what the particular governors do. > > > > Another benefit is that the common code does not need a pointer to > > a governor-related structure to get to the mutex which sometimes > > helps. > > > > Finally, it makes the code generally easier to follow. > > > > Signed-off-by: Rafael J. Wysocki <rafael.j.wyso...@intel.com> > > Acked-by: Saravana Kannan <skan...@codeaurora.org> > > Acked-by: Viresh Kumar <viresh.ku...@linaro.org>
Thanks! One more observation here. If we are able to eliminate dbs_data_mutex from update_sampling_rate(), then cpufreq_governor_dbs() becomes the only user of that lock. Further, if we can guarantee that the governor's ->governor callback will always be invoked under policy->rwsem, dbs_data_mutex becomes unnecessary and may be dropped. Thanks, Rafael
