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sched/cpufreq: Use the DEADLINE utilization signal 

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>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luca Abeni <luca.abeni@santannapisa.it>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: alessio.balsini@arm.com
Cc: bristot@redhat.com
Cc: dietmar.eggemann@arm.com
Cc: joelaf@google.com
Cc: juri.lelli@redhat.com
Cc: mathieu.poirier@linaro.org
Cc: morten.rasmussen@arm.com
Cc: patrick.bellasi@arm.com
Cc: rjw@rjwysocki.net
Cc: rostedt@goodmis.org
Cc: tkjos@android.com
Cc: tommaso.cucinotta@santannapisa.it
Cc: vincent.guittot@linaro.org
Link: http://lkml.kernel.org/r/20171204102325.5110-2-juri.lelli@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Juri Lelli 2017-12-04 11:23:18 +01:00 committed by Ingo Molnar
parent 34be39305a
commit d4edd662ac
3 changed files with 25 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
include/linux/sched/cpufreq.h
View File

@ -12,8 +12,6 @@
#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);

25
kernel/sched/cpufreq_schedutil.c
View File

@ -179,12 +179,17 @@ static unsigned int get_next_freq(struct sugov_policy *sg_policy,
static void sugov_get_util(unsigned long *util, unsigned long *max, int cpu)
{
struct rq *rq = cpu_rq(cpu);
unsigned long cfs_max;
unsigned long util_cfs = cpu_util_cfs(rq);
unsigned long util_dl = cpu_util_dl(rq);
cfs_max = arch_scale_cpu_capacity(NULL, cpu);
*max = arch_scale_cpu_capacity(NULL, cpu);
*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(util_cfs + util_dl, *max);
}
static void sugov_set_iowait_boost(struct sugov_cpu *sg_cpu, u64 time)
@ -271,7 +276,7 @@ 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, sg_cpu->cpu);
@ -316,7 +321,7 @@ static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu, u64 time)
j_sg_cpu->iowait_boost_pending = false;
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;
@ -352,7 +357,7 @@ 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);
@ -382,9 +387,9 @@ 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

10
kernel/sched/sched.h
View File

@ -2084,3 +2084,13 @@ static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) {}
#else /* arch_scale_freq_capacity */
#define arch_scale_freq_invariant() (false)
#endif
static inline unsigned long cpu_util_dl(struct rq *rq)
{
return (rq->dl.running_bw * SCHED_CAPACITY_SCALE) >> BW_SHIFT;
}
static inline unsigned long cpu_util_cfs(struct rq *rq)
{
return rq->cfs.avg.util_avg;
}