Messages in this thread | | | Subject | Re: [PATCH V6 2/3] cpuidle: play_idle: Specify play_idle with an idle state | From | Daniel Lezcano <> | Date | Wed, 13 Nov 2019 13:37:14 +0100 |
| |
On 08/11/2019 02:20, Rafael J. Wysocki wrote: > 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.
[ ... ]
>> /** >> 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).
I'm confused with the "... ugly, *or* ...". In any case we have to specify a latency constraint to play_idle(), no?
> 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!).
-- <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs
Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook | <http://twitter.com/#!/linaroorg> Twitter | <http://www.linaro.org/linaro-blog/> Blog
| |