Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [PATCH v2 2/10] cpufreq: governor: Use common mutex for dbs_data protection | Date | Sun, 07 Feb 2016 15:33:07 +0100 |
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On Sunday, February 07, 2016 03:01:12 PM Viresh Kumar wrote: > On 05-02-16, 23:59, Rafael J. Wysocki wrote: > > 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. > > That will be guaranteed with my 7 patches, which I will rebase and send again. > > But there are cases where a single dbs_data is going to be used for multiple > policies and so relying on policy->rwsem isn't going to be sufficient. > > But, yeah, we should be able to narrow down the locked area I believe.
That should only be a matter of protecting the gov->gdbs_data object and its refcount then.
Thanks, Rafael
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