| Message ID | 20170705085905.6558-8-juri.lelli@arm.com (mailing list archive) |
|---|---|
| State | RFC, archived |
| Headers | show |
On Wed, 5 Jul 2017 09:59:04 +0100 Juri Lelli <juri.lelli@arm.com> wrote: > Currently, frequency and cpu capacity scaling is only performed on > CONFIG_SMP systems (as CFS PELT signals are only present for such > systems). However, other scheduling classes want to do freq/cpu scaling, > and for !CONFIG_SMP configurations as well. > > arch_scale_freq_capacity is useful to implement frequency scaling even > on !CONFIG_SMP platforms, so we simply move it outside CONFIG_SMP > ifdeffery. > > Even if arch_scale_cpu_capacity is not useful on !CONFIG_SMP platforms, > we make a default implementation available for such configurations anyway > to simplify scheduler code doing CPU scale invariance. > Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> -- Steve > Signed-off-by: Juri Lelli <juri.lelli@arm.com> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Ingo Molnar <mingo@kernel.org> > --- > include/linux/sched/topology.h | 12 ++++++------ > kernel/sched/sched.h | 13 ++++++++++--- > 2 files changed, 16 insertions(+), 9 deletions(-) > > diff --git a/include/linux/sched/topology.h b/include/linux/sched/topology.h > index 7d065abc7a47..953cf4f889ec 100644 > --- a/include/linux/sched/topology.h > +++ b/include/linux/sched/topology.h > @@ -6,6 +6,12 @@ > #include <linux/sched/idle.h> > > /* > + * Increase resolution of cpu_capacity calculations > + */ > +#define SCHED_CAPACITY_SHIFT SCHED_FIXEDPOINT_SHIFT > +#define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT) > + > +/* > * sched-domains (multiprocessor balancing) declarations: > */ > #ifdef CONFIG_SMP > @@ -26,12 +32,6 @@ > #define SD_OVERLAP 0x2000 /* sched_domains of this level overlap */ > #define SD_NUMA 0x4000 /* cross-node balancing */ > > -/* > - * Increase resolution of cpu_capacity calculations > - */ > -#define SCHED_CAPACITY_SHIFT SCHED_FIXEDPOINT_SHIFT > -#define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT) > - > #ifdef CONFIG_SCHED_SMT > static inline int cpu_smt_flags(void) > { > diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h > index ec5769288927..178f4a5df2fa 100644 > --- a/kernel/sched/sched.h > +++ b/kernel/sched/sched.h > @@ -1668,9 +1668,6 @@ static inline int hrtick_enabled(struct rq *rq) > > #endif /* CONFIG_SCHED_HRTICK */ > > -#ifdef CONFIG_SMP > -extern void sched_avg_update(struct rq *rq); > - > #ifndef arch_scale_freq_capacity > static __always_inline > unsigned long arch_scale_freq_capacity(int cpu) > @@ -1679,6 +1676,9 @@ unsigned long arch_scale_freq_capacity(int cpu) > } > #endif > > +#ifdef CONFIG_SMP > +extern void sched_avg_update(struct rq *rq); > + > #ifndef arch_scale_cpu_capacity > static __always_inline > unsigned long arch_scale_cpu_capacity(struct sched_domain *sd, int cpu) > @@ -1696,6 +1696,13 @@ static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) > sched_avg_update(rq); > } > #else > +#ifndef arch_scale_cpu_capacity > +static __always_inline > +unsigned long arch_scale_cpu_capacity(void __always_unused *sd, int cpu) > +{ > + return SCHED_CAPACITY_SCALE; > +} > +#endif > static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) { } > static inline void sched_avg_update(struct rq *rq) { } > #endif
diff --git a/include/linux/sched/topology.h b/include/linux/sched/topology.h index 7d065abc7a47..953cf4f889ec 100644 --- a/include/linux/sched/topology.h +++ b/include/linux/sched/topology.h @@ -6,6 +6,12 @@ #include <linux/sched/idle.h> /* + * Increase resolution of cpu_capacity calculations + */ +#define SCHED_CAPACITY_SHIFT SCHED_FIXEDPOINT_SHIFT +#define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT) + +/* * sched-domains (multiprocessor balancing) declarations: */ #ifdef CONFIG_SMP @@ -26,12 +32,6 @@ #define SD_OVERLAP 0x2000 /* sched_domains of this level overlap */ #define SD_NUMA 0x4000 /* cross-node balancing */ -/* - * Increase resolution of cpu_capacity calculations - */ -#define SCHED_CAPACITY_SHIFT SCHED_FIXEDPOINT_SHIFT -#define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT) - #ifdef CONFIG_SCHED_SMT static inline int cpu_smt_flags(void) { diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index ec5769288927..178f4a5df2fa 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1668,9 +1668,6 @@ static inline int hrtick_enabled(struct rq *rq) #endif /* CONFIG_SCHED_HRTICK */ -#ifdef CONFIG_SMP -extern void sched_avg_update(struct rq *rq); - #ifndef arch_scale_freq_capacity static __always_inline unsigned long arch_scale_freq_capacity(int cpu) @@ -1679,6 +1676,9 @@ unsigned long arch_scale_freq_capacity(int cpu) } #endif +#ifdef CONFIG_SMP +extern void sched_avg_update(struct rq *rq); + #ifndef arch_scale_cpu_capacity static __always_inline unsigned long arch_scale_cpu_capacity(struct sched_domain *sd, int cpu) @@ -1696,6 +1696,13 @@ static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) sched_avg_update(rq); } #else +#ifndef arch_scale_cpu_capacity +static __always_inline +unsigned long arch_scale_cpu_capacity(void __always_unused *sd, int cpu) +{ + return SCHED_CAPACITY_SCALE; +} +#endif static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) { } static inline void sched_avg_update(struct rq *rq) { } #endif
Currently, frequency and cpu capacity scaling is only performed on CONFIG_SMP systems (as CFS PELT signals are only present for such systems). However, other scheduling classes want to do freq/cpu scaling, and for !CONFIG_SMP configurations as well. arch_scale_freq_capacity is useful to implement frequency scaling even on !CONFIG_SMP platforms, so we simply move it outside CONFIG_SMP ifdeffery. Even if arch_scale_cpu_capacity is not useful on !CONFIG_SMP platforms, we make a default implementation available for such configurations anyway to simplify scheduler code doing CPU scale invariance. Signed-off-by: Juri Lelli <juri.lelli@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> --- include/linux/sched/topology.h | 12 ++++++------ kernel/sched/sched.h | 13 ++++++++++--- 2 files changed, 16 insertions(+), 9 deletions(-)