Messages in this thread Patch in this message | | | From | Juri Lelli <> | Subject | [RFC PATCH v1 1/8] sched/cpufreq_schedutil: make use of DEADLINE utilization signal | Date | Wed, 5 Jul 2017 09:58:58 +0100 |
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SCHED_DEADLINE tracks active utilization signal with a per dl_rq variable named running_bw.
Make use of that to drive cpu frequency selection: add up FAIR and DEADLINE contribution to get the required CPU capacity to handle both requirements (while RT still selects max frequency).
Co-authored-by: Claudio Scordino <claudio@evidence.eu.com> Signed-off-by: Juri Lelli <juri.lelli@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Luca Abeni <luca.abeni@santannapisa.it> --- Changes from RFCv0:
- use BW_SHIFT (Peter) - add comment about guaranteed and requested freq (Peter) - modify comment about go to max behaviour (Claudio) --- include/linux/sched/cpufreq.h | 2 -- kernel/sched/cpufreq_schedutil.c | 25 +++++++++++++++---------- 2 files changed, 15 insertions(+), 12 deletions(-)
diff --git a/include/linux/sched/cpufreq.h b/include/linux/sched/cpufreq.h index d2be2ccbb372..39640bb3a8ee 100644 --- a/include/linux/sched/cpufreq.h +++ b/include/linux/sched/cpufreq.h @@ -11,8 +11,6 @@ #define SCHED_CPUFREQ_DL (1U << 1) #define SCHED_CPUFREQ_IOWAIT (1U << 2) -#define SCHED_CPUFREQ_RT_DL (SCHED_CPUFREQ_RT | SCHED_CPUFREQ_DL) - #ifdef CONFIG_CPU_FREQ struct update_util_data { void (*func)(struct update_util_data *data, u64 time, unsigned int flags); diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index 076a2e31951c..f2494d1fc8ef 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -157,12 +157,17 @@ static unsigned int get_next_freq(struct sugov_policy *sg_policy, static void sugov_get_util(unsigned long *util, unsigned long *max) { struct rq *rq = this_rq(); - unsigned long cfs_max; + unsigned long dl_util = (rq->dl.running_bw * SCHED_CAPACITY_SCALE) + >> BW_SHIFT; - cfs_max = arch_scale_cpu_capacity(NULL, smp_processor_id()); + *max = arch_scale_cpu_capacity(NULL, smp_processor_id()); - *util = min(rq->cfs.avg.util_avg, cfs_max); - *max = cfs_max; + /* + * Ideally we would like to set util_dl as min/guaranteed freq and + * util_cfs + util_dl as requested freq. However, cpufreq is not yet + * ready for such an interface. So, we only do the latter for now. + */ + *util = min(rq->cfs.avg.util_avg + dl_util, *max); } static void sugov_set_iowait_boost(struct sugov_cpu *sg_cpu, u64 time, @@ -226,7 +231,7 @@ static void sugov_update_single(struct update_util_data *hook, u64 time, busy = sugov_cpu_is_busy(sg_cpu); - if (flags & SCHED_CPUFREQ_RT_DL) { + if (flags & SCHED_CPUFREQ_RT) { next_f = policy->cpuinfo.max_freq; } else { sugov_get_util(&util, &max); @@ -266,7 +271,7 @@ static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu, u64 time) j_sg_cpu->iowait_boost = 0; continue; } - if (j_sg_cpu->flags & SCHED_CPUFREQ_RT_DL) + if (j_sg_cpu->flags & SCHED_CPUFREQ_RT) return policy->cpuinfo.max_freq; j_util = j_sg_cpu->util; @@ -302,7 +307,7 @@ static void sugov_update_shared(struct update_util_data *hook, u64 time, sg_cpu->last_update = time; if (sugov_should_update_freq(sg_policy, time)) { - if (flags & SCHED_CPUFREQ_RT_DL) + if (flags & SCHED_CPUFREQ_RT) next_f = sg_policy->policy->cpuinfo.max_freq; else next_f = sugov_next_freq_shared(sg_cpu, time); @@ -332,9 +337,9 @@ static void sugov_irq_work(struct irq_work *irq_work) sg_policy = container_of(irq_work, struct sugov_policy, irq_work); /* - * For RT and deadline tasks, the schedutil governor shoots the - * frequency to maximum. Special care must be taken to ensure that this - * kthread doesn't result in the same behavior. + * For RT tasks, the schedutil governor shoots the frequency to maximum. + * Special care must be taken to ensure that this kthread doesn't result + * in the same behavior. * * This is (mostly) guaranteed by the work_in_progress flag. The flag is * updated only at the end of the sugov_work() function and before that -- 2.11.0
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