Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [PATCH V6 2/3] cpuidle: play_idle: Specify play_idle with an idle state | Date | Fri, 08 Nov 2019 02:20:27 +0100 |
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On Wednesday, October 30, 2019 8:51:40 AM CET Daniel Lezcano wrote: > Currently, the play_idle function does not allow to tell which idle > state we want to go. Improve this by passing the idle state as > parameter to the function. > > Export cpuidle_find_deepest_state() symbol as it is used from the > intel_powerclamp driver as a module. > > There is no functional changes, the cpuidle state is the deepest one. > > Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> > Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org> > Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> > --- > V6: > - Change variable name 'state' -> 'index': > https://lkml.org/lkml/2019/10/28/874 > V4: > - Add EXPORT_SYMBOL_GPL(cpuidle_find_deepest_state) for the > intel_powerclamp driver when this one is compiled as a module > V3: > - Add missing cpuidle.h header > --- > drivers/cpuidle/cpuidle.c | 1 + > drivers/powercap/idle_inject.c | 4 +++- > drivers/thermal/intel/intel_powerclamp.c | 4 +++- > include/linux/cpu.h | 2 +- > kernel/sched/idle.c | 4 ++-- > 5 files changed, 10 insertions(+), 5 deletions(-) > > diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c > index 18523ea6b11b..b871fc2e8e67 100644 > --- a/drivers/cpuidle/cpuidle.c > +++ b/drivers/cpuidle/cpuidle.c > @@ -126,6 +126,7 @@ int cpuidle_find_deepest_state(void) > > return find_deepest_state(drv, dev, UINT_MAX, 0, false); > } > +EXPORT_SYMBOL_GPL(cpuidle_find_deepest_state);
That doesn't appear to be really necessary to me.
> > #ifdef CONFIG_SUSPEND > static void enter_s2idle_proper(struct cpuidle_driver *drv, > diff --git a/drivers/powercap/idle_inject.c b/drivers/powercap/idle_inject.c > index cd1270614cc6..233c878cbf46 100644 > --- a/drivers/powercap/idle_inject.c > +++ b/drivers/powercap/idle_inject.c > @@ -38,6 +38,7 @@ > #define pr_fmt(fmt) "ii_dev: " fmt > > #include <linux/cpu.h> > +#include <linux/cpuidle.h> > #include <linux/hrtimer.h> > #include <linux/kthread.h> > #include <linux/sched.h> > @@ -138,7 +139,8 @@ static void idle_inject_fn(unsigned int cpu) > */ > iit->should_run = 0; > > - play_idle(READ_ONCE(ii_dev->idle_duration_us)); > + play_idle(READ_ONCE(ii_dev->idle_duration_us), > + cpuidle_find_deepest_state());
The next patch changes this again and I'm not sure why this intermediate change is useful.
> } > > /** > diff --git a/drivers/thermal/intel/intel_powerclamp.c b/drivers/thermal/intel/intel_powerclamp.c > index 53216dcbe173..b55786c169ae 100644 > --- a/drivers/thermal/intel/intel_powerclamp.c > +++ b/drivers/thermal/intel/intel_powerclamp.c > @@ -29,6 +29,7 @@ > #include <linux/delay.h> > #include <linux/kthread.h> > #include <linux/cpu.h> > +#include <linux/cpuidle.h> > #include <linux/thermal.h> > #include <linux/slab.h> > #include <linux/tick.h> > @@ -430,7 +431,8 @@ static void clamp_idle_injection_func(struct kthread_work *work) > if (should_skip) > goto balance; > > - play_idle(jiffies_to_usecs(w_data->duration_jiffies)); > + play_idle(jiffies_to_usecs(w_data->duration_jiffies), > + cpuidle_find_deepest_state());
I don't see a reason for changing the code here like this.
What you really need is to have a way to set a limit on the idle state exit latency for idle injection on ARM.
For that you can pass the exit latency limit to play_idle(), but then you need to change powerclamp to pass UNIT_MAX or similar which is ugly, or you can redefine cpuidle_use_deepest_state() to take the exit latency limit as the arg (with 0 meaning use_deepest_state == false).
In the latter case, it would be quite straightforward to add an exit_latency argument to cpuidle_find_deepest_state() and note that find_deepest_state() takes a max_latency arg already, so that would be a trivial change (hint!).
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