| Message ID | 1409815075-4180-2-git-send-email-chuansheng.liu@intel.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On 09/04/2014 09:17 AM, Chuansheng Liu wrote: > Currently kick_all_cpus_sync() can break non-polling idle cpus > thru IPI interrupts. > > But sometimes we need to break the polling idle cpus immediately > to reselect the suitable c-state, also for non-idle cpus, we need > to do nothing if we try to wake up them. > > Here adding one new function wake_up_all_idle_cpus() to let all cpus > out of idle based on function wake_up_if_idle(). Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> > Signed-off-by: Chuansheng Liu <chuansheng.liu@intel.com> > --- > include/linux/smp.h | 2 ++ > kernel/smp.c | 22 ++++++++++++++++++++++ > 2 files changed, 24 insertions(+) > > diff --git a/include/linux/smp.h b/include/linux/smp.h > index 34347f2..93dff5f 100644 > --- a/include/linux/smp.h > +++ b/include/linux/smp.h > @@ -100,6 +100,7 @@ int smp_call_function_any(const struct cpumask *mask, > smp_call_func_t func, void *info, int wait); > > void kick_all_cpus_sync(void); > +void wake_up_all_idle_cpus(void); > > /* > * Generic and arch helpers > @@ -148,6 +149,7 @@ smp_call_function_any(const struct cpumask *mask, smp_call_func_t func, > } > > static inline void kick_all_cpus_sync(void) { } > +static inline void wake_up_all_idle_cpus(void) { } > > #endif /* !SMP */ > > diff --git a/kernel/smp.c b/kernel/smp.c > index aff8aa1..9e0d0b2 100644 > --- a/kernel/smp.c > +++ b/kernel/smp.c > @@ -13,6 +13,7 @@ > #include <linux/gfp.h> > #include <linux/smp.h> > #include <linux/cpu.h> > +#include <linux/sched.h> > > #include "smpboot.h" > > @@ -699,3 +700,24 @@ void kick_all_cpus_sync(void) > smp_call_function(do_nothing, NULL, 1); > } > EXPORT_SYMBOL_GPL(kick_all_cpus_sync); > + > +/** > + * wake_up_all_idle_cpus - break all cpus out of idle > + * wake_up_all_idle_cpus try to break all cpus which is in idle state even > + * including idle polling cpus, for non-idle cpus, we will do nothing > + * for them. > + */ > +void wake_up_all_idle_cpus(void) > +{ > + int cpu; > + > + preempt_disable(); > + for_each_online_cpu(cpu) { > + if (cpu == smp_processor_id()) > + continue; > + > + wake_up_if_idle(cpu); > + } > + preempt_enable(); > +} > +EXPORT_SYMBOL_GPL(wake_up_all_idle_cpus); >
diff --git a/include/linux/smp.h b/include/linux/smp.h index 34347f2..93dff5f 100644 --- a/include/linux/smp.h +++ b/include/linux/smp.h @@ -100,6 +100,7 @@ int smp_call_function_any(const struct cpumask *mask, smp_call_func_t func, void *info, int wait); void kick_all_cpus_sync(void); +void wake_up_all_idle_cpus(void); /* * Generic and arch helpers @@ -148,6 +149,7 @@ smp_call_function_any(const struct cpumask *mask, smp_call_func_t func, } static inline void kick_all_cpus_sync(void) { } +static inline void wake_up_all_idle_cpus(void) { } #endif /* !SMP */ diff --git a/kernel/smp.c b/kernel/smp.c index aff8aa1..9e0d0b2 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -13,6 +13,7 @@ #include <linux/gfp.h> #include <linux/smp.h> #include <linux/cpu.h> +#include <linux/sched.h> #include "smpboot.h" @@ -699,3 +700,24 @@ void kick_all_cpus_sync(void) smp_call_function(do_nothing, NULL, 1); } EXPORT_SYMBOL_GPL(kick_all_cpus_sync); + +/** + * wake_up_all_idle_cpus - break all cpus out of idle + * wake_up_all_idle_cpus try to break all cpus which is in idle state even + * including idle polling cpus, for non-idle cpus, we will do nothing + * for them. + */ +void wake_up_all_idle_cpus(void) +{ + int cpu; + + preempt_disable(); + for_each_online_cpu(cpu) { + if (cpu == smp_processor_id()) + continue; + + wake_up_if_idle(cpu); + } + preempt_enable(); +} +EXPORT_SYMBOL_GPL(wake_up_all_idle_cpus);
Currently kick_all_cpus_sync() can break non-polling idle cpus thru IPI interrupts. But sometimes we need to break the polling idle cpus immediately to reselect the suitable c-state, also for non-idle cpus, we need to do nothing if we try to wake up them. Here adding one new function wake_up_all_idle_cpus() to let all cpus out of idle based on function wake_up_if_idle(). Signed-off-by: Chuansheng Liu <chuansheng.liu@intel.com> --- include/linux/smp.h | 2 ++ kernel/smp.c | 22 ++++++++++++++++++++++ 2 files changed, 24 insertions(+)