lkml.org 
[lkml]   [2018]   [Jan]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[tip:sched/core] sched/cpufreq: Use the DEADLINE utilization signal
    Commit-ID:  d4edd662ac1657126df7ffd74a278958b133a77d
    Gitweb: https://git.kernel.org/tip/d4edd662ac1657126df7ffd74a278958b133a77d
    Author: Juri Lelli <juri.lelli@arm.com>
    AuthorDate: Mon, 4 Dec 2017 11:23:18 +0100
    Committer: Ingo Molnar <mingo@kernel.org>
    CommitDate: Wed, 10 Jan 2018 11:30:32 +0100

    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>
    ---
    include/linux/sched/cpufreq.h | 2 --
    kernel/sched/cpufreq_schedutil.c | 25 +++++++++++++++----------
    kernel/sched/sched.h | 10 ++++++++++
    3 files changed, 25 insertions(+), 12 deletions(-)

    diff --git a/include/linux/sched/cpufreq.h b/include/linux/sched/cpufreq.h
    index d1ad3d8..0b55834 100644
    --- a/include/linux/sched/cpufreq.h
    +++ b/include/linux/sched/cpufreq.h
    @@ -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);
    diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
    index 6dd1ec9..8d266bc 100644
    --- a/kernel/sched/cpufreq_schedutil.c
    +++ b/kernel/sched/cpufreq_schedutil.c
    @@ -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
    diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
    index 43f5d6e..136ab50 100644
    --- a/kernel/sched/sched.h
    +++ b/kernel/sched/sched.h
    @@ -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;
    +}
    \
     
     \ /
      Last update: 2018-01-14 23:21    [W:5.292 / U:0.020 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site