summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorWanpeng Li <wanpeng.li@hotmail.com>2016-04-22 17:07:24 +0800
committerIngo Molnar <mingo@kernel.org>2016-04-28 10:39:54 +0200
commit594dd290cf5403a9a5818619dfff42d8e8e0518e (patch)
tree31fa5c3c77c6c5cc293a91bd85cef310f0b988e6
parentfec148c000d0f9ac21679601722811eb60b4cc52 (diff)
sched/cpufreq: Optimize cpufreq update kicker to avoid update multiple times
Sometimes delta_exec is 0 due to update_curr() is called multiple times, this is captured by: u64 delta_exec = rq_clock_task(rq) - curr->se.exec_start; This patch optimizes the cpufreq update kicker by bailing out when nothing changed, it will benefit the upcoming schedutil, since otherwise it will (over)react to the special util/max combination. Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1461316044-9520-1-git-send-email-wanpeng.li@hotmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--kernel/sched/deadline.c8
-rw-r--r--kernel/sched/rt.c8
2 files changed, 8 insertions, 8 deletions
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index affd97ec9f65..8f9b5af4e857 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -717,10 +717,6 @@ static void update_curr_dl(struct rq *rq)
if (!dl_task(curr) || !on_dl_rq(dl_se))
return;
- /* Kick cpufreq (see the comment in linux/cpufreq.h). */
- if (cpu_of(rq) == smp_processor_id())
- cpufreq_trigger_update(rq_clock(rq));
-
/*
* Consumed budget is computed considering the time as
* observed by schedulable tasks (excluding time spent
@@ -736,6 +732,10 @@ static void update_curr_dl(struct rq *rq)
return;
}
+ /* kick cpufreq (see the comment in linux/cpufreq.h). */
+ if (cpu_of(rq) == smp_processor_id())
+ cpufreq_trigger_update(rq_clock(rq));
+
schedstat_set(curr->se.statistics.exec_max,
max(curr->se.statistics.exec_max, delta_exec));
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index c41ea7ac1764..19e13060fcd5 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -953,14 +953,14 @@ static void update_curr_rt(struct rq *rq)
if (curr->sched_class != &rt_sched_class)
return;
- /* Kick cpufreq (see the comment in linux/cpufreq.h). */
- if (cpu_of(rq) == smp_processor_id())
- cpufreq_trigger_update(rq_clock(rq));
-
delta_exec = rq_clock_task(rq) - curr->se.exec_start;
if (unlikely((s64)delta_exec <= 0))
return;
+ /* Kick cpufreq (see the comment in linux/cpufreq.h). */
+ if (cpu_of(rq) == smp_processor_id())
+ cpufreq_trigger_update(rq_clock(rq));
+
schedstat_set(curr->se.statistics.exec_max,
max(curr->se.statistics.exec_max, delta_exec));