Re: [PATCH v10 1/3] cpufreq: Add mechanism for registering utilization update callbacks
From: Rafael J. Wysocki
Date: Wed Mar 09 2016 - 08:23:15 EST
On Wed, Mar 9, 2016 at 1:35 PM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> On Mon, Feb 15, 2016 at 10:47:22PM +0100, Rafael J. Wysocki wrote:
>> From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>> 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 <rafael.j.wysocki@xxxxxxxxx>
>> Acked-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
>> drivers/cpufreq/cpufreq.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
>> include/linux/cpufreq.h | 34 ++++++++++++++++++++++++++++++++++
>> kernel/sched/deadline.c | 4 ++++
>> kernel/sched/fair.c | 26 +++++++++++++++++++++++++-
>> kernel/sched/rt.c | 4 ++++
>> kernel/sched/sched.h | 1 +
>> 6 files changed, 113 insertions(+), 1 deletion(-)
> So with the understanding that we'll work on getting rid of
That definitely is the plan.
> Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
> Also, Vincent had some concerns about the exact placement of the
> callback, and I see no problem in moving it if there's need.
Yup, same here.