user/sven/linux.git/include/linux/cpufreq.h, branch v4.7

cpufreq: Call cpufreq_disable_fast_switch() in sugov_exit()

2016-04-08T20:41:36Z

Due to differences in the cpufreq core's handling of runtime CPU offline and nonboot CPUs disabling during system suspend-to-RAM, fast frequency switching gets disabled after a suspend-to-RAM and resume cycle on all of the nonboot CPUs. To prevent that from happening, move the invocation of cpufreq_disable_fast_switch() from cpufreq_exit_governor() to sugov_exit(), as the schedutil governor is the only user of fast frequency switching today anyway. That simply prevents cpufreq_disable_fast_switch() from being called without invoking the ->governor callback for the CPUFREQ_GOV_POLICY_EXIT event (which happens during system suspend now). Fixes: b7898fda5bc7 (cpufreq: Support for fast frequency switching) Signed-off-by: Rafael J. Wysocki Acked-by: Viresh Kumar

cpufreq: Support for fast frequency switching

2016-04-01T23:09:03Z

Modify the ACPI cpufreq driver to provide a method for switching CPU frequencies from interrupt context and update the cpufreq core to support that method if available. Introduce a new cpufreq driver callback, ->fast_switch, to be invoked for frequency switching from interrupt context by (future) governors supporting that feature via (new) helper function cpufreq_driver_fast_switch(). Add two new policy flags, fast_switch_possible, to be set by the cpufreq driver if fast frequency switching can be used for the given policy and fast_switch_enabled, to be set by the governor if it is going to use fast frequency switching for the given policy. Also add a helper for setting the latter. Since fast frequency switching is inherently incompatible with cpufreq transition notifiers, make it possible to set the fast_switch_enabled only if there are no transition notifiers already registered and make the registration of new transition notifiers fail if fast_switch_enabled is set for at least one policy. Implement the ->fast_switch callback in the ACPI cpufreq driver and make it set fast_switch_possible during policy initialization as appropriate. Signed-off-by: Rafael J. Wysocki Acked-by: Viresh Kumar

cpufreq: Move governor symbols to cpufreq.h

2016-04-01T23:09:02Z

Move definitions of symbols related to transition latency and sampling rate to include/linux/cpufreq.h so they can be used by (future) goverernors located outside of drivers/cpufreq/. No functional changes. Signed-off-by: Rafael J. Wysocki Acked-by: Viresh Kumar

cpufreq: Move governor attribute set headers to cpufreq.h

2016-04-01T23:09:02Z

Move definitions and function headers related to struct gov_attr_set to include/linux/cpufreq.h so they can be used by (future) goverernors located outside of drivers/cpufreq/. No functional changes. Signed-off-by: Rafael J. Wysocki Acked-by: Viresh Kumar

Merge branch 'pm-cpufreq-governor' into pm-cpufreq

2016-03-10T19:46:03Z

cpufreq: Move scheduler-related code to the sched directory

2016-03-10T19:44:47Z

Create cpufreq.c under kernel/sched/ and move the cpufreq code related to the scheduler to that file and to sched.h. Redefine cpufreq_update_util() as a static inline function to avoid function calls at its call sites in the scheduler code (as suggested by Peter Zijlstra). Also move the definition of struct update_util_data and declaration of cpufreq_set_update_util_data() from include/linux/cpufreq.h to include/linux/sched.h. Signed-off-by: Rafael J. Wysocki Acked-by: Peter Zijlstra (Intel)

cpufreq: Remove 'policy->governor_enabled'

2016-03-09T13:41:12Z

The entire sequence of events (like INIT/START or STOP/EXIT) for which cpufreq_governor() is called, is guaranteed to be protected by policy->rwsem now. The additional checks that were added earlier (as we were forced to drop policy->rwsem before calling cpufreq_governor() for EXIT event), aren't required anymore. Over that, they weren't sufficient really. They just take care of START/STOP events, but not INIT/EXIT and the state machine was never maintained properly by them. Kill the unnecessary checks and policy->governor_enabled field. Signed-off-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki

Revert "cpufreq: Drop rwsem lock around CPUFREQ_GOV_POLICY_EXIT"

2016-03-09T13:40:59Z

Earlier, when the struct freq-attr was used to represent governor attributes, the standard cpufreq show/store sysfs attribute callbacks were applied to the governor tunable attributes and they always acquire the policy->rwsem lock before carrying out the operation. That could have resulted in an ABBA deadlock if governor tunable attributes are removed under policy->rwsem while one of them is being accessed concurrently (if sysfs attributes removal wins the race, it will wait for the access to complete with policy->rwsem held while the attribute callback will block on policy->rwsem indefinitely). We attempted to address this issue by dropping policy->rwsem around governor tunable attributes removal (that is, around invocations of the ->governor callback with the event arg equal to CPUFREQ_GOV_POLICY_EXIT) in cpufreq_set_policy(), but that opened up race conditions that had not been possible with policy->rwsem held all the time. The previous commit, "cpufreq: governor: New sysfs show/store callbacks for governor tunables", fixed the original ABBA deadlock by adding new governor specific show/store callbacks. We don't have to drop rwsem around invocations of governor event CPUFREQ_GOV_POLICY_EXIT anymore, and original fix can be reverted now. Fixes: 955ef4833574 (cpufreq: Drop rwsem lock around CPUFREQ_GOV_POLICY_EXIT) Signed-off-by: Viresh Kumar Reported-by: Juri Lelli Tested-by: Juri Lelli Tested-by: Shilpasri G Bhat Signed-off-by: Rafael J. Wysocki

cpufreq: Add mechanism for registering utilization update callbacks

2016-03-09T13:39:19Z

Introduce a mechanism by which parts of the cpufreq subsystem ("setpolicy" drivers or the core) can register callbacks to be executed from cpufreq_update_util() which is invoked by the scheduler's update_load_avg() on CPU utilization changes. This allows the "setpolicy" drivers to dispense with their timers and do all of the computations they need and frequency/voltage adjustments in the update_load_avg() code path, among other things. The update_load_avg() changes were suggested by Peter Zijlstra. Signed-off-by: Rafael J. Wysocki Acked-by: Viresh Kumar Acked-by: Peter Zijlstra (Intel) Acked-by: Ingo Molnar

cpufreq: Simplify the cpufreq_for_each_valid_entry()

2016-02-26T21:11:56Z

That macro uses an internal static inline function that is first totally unnecessary and second hard to read, so simplify it and get rid of that monster. No functional changes. Signed-off-by: Rafael J. Wysocki Acked-by: Viresh Kumar