From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Thu, 24 Mar 2016 16:42:50 +0000 (-0700)
Subject: Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel... 
X-Git-Tag: v4.6-rc1~36
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=be53f58fa0fcd97c62a84f2eb98cff528f8b2443;p=linux.git

Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Ingo Molnar:
 "Misc fixes: a cgroup fix, a fair-scheduler migration accounting fix, a
  cputime fix and two cpuacct cleanups"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/cpuacct: Simplify the cpuacct code
  sched/cpuacct: Rename parameter in cpuusage_write() for readability
  sched/fair: Add comments to explain select_idle_sibling()
  sched/fair: Fix fairness issue on migration
  sched/cgroup: Fix/cleanup cgroup teardown/init
  sched/cputime: Fix steal time accounting vs. CPU hotplug
---

be53f58fa0fcd97c62a84f2eb98cff528f8b2443
diff --cc kernel/sched/sched.h
index 382848a24ed9,e6d4a3fa3660..ec2e8d23527e
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@@ -1794,50 -1794,15 +1794,63 @@@ static inline u64 irq_time_read(int cpu
  #endif /* CONFIG_64BIT */
  #endif /* CONFIG_IRQ_TIME_ACCOUNTING */
  
 +#ifdef CONFIG_CPU_FREQ
 +DECLARE_PER_CPU(struct update_util_data *, cpufreq_update_util_data);
 +
 +/**
 + * cpufreq_update_util - Take a note about CPU utilization changes.
 + * @time: Current time.
 + * @util: Current utilization.
 + * @max: Utilization ceiling.
 + *
 + * This function is called by the scheduler on every invocation of
 + * update_load_avg() on the CPU whose utilization is being updated.
 + *
 + * It can only be called from RCU-sched read-side critical sections.
 + */
 +static inline void cpufreq_update_util(u64 time, unsigned long util, unsigned long max)
 +{
 +       struct update_util_data *data;
 +
 +       data = rcu_dereference_sched(*this_cpu_ptr(&cpufreq_update_util_data));
 +       if (data)
 +               data->func(data, time, util, max);
 +}
 +
 +/**
 + * cpufreq_trigger_update - Trigger CPU performance state evaluation if needed.
 + * @time: Current time.
 + *
 + * The way cpufreq is currently arranged requires it to evaluate the CPU
 + * performance state (frequency/voltage) on a regular basis to prevent it from
 + * being stuck in a completely inadequate performance level for too long.
 + * That is not guaranteed to happen if the updates are only triggered from CFS,
 + * though, because they may not be coming in if RT or deadline tasks are active
 + * all the time (or there are RT and DL tasks only).
 + *
 + * As a workaround for that issue, this function is called by the RT and DL
 + * sched classes to trigger extra cpufreq updates to prevent it from stalling,
 + * but that really is a band-aid.  Going forward it should be replaced with
 + * solutions targeted more specifically at RT and DL tasks.
 + */
 +static inline void cpufreq_trigger_update(u64 time)
 +{
 +	cpufreq_update_util(time, ULONG_MAX, 0);
 +}
 +#else
 +static inline void cpufreq_update_util(u64 time, unsigned long util, unsigned long max) {}
 +static inline void cpufreq_trigger_update(u64 time) {}
 +#endif /* CONFIG_CPU_FREQ */
++
+ static inline void account_reset_rq(struct rq *rq)
+ {
+ #ifdef CONFIG_IRQ_TIME_ACCOUNTING
+ 	rq->prev_irq_time = 0;
+ #endif
+ #ifdef CONFIG_PARAVIRT
+ 	rq->prev_steal_time = 0;
+ #endif
+ #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
+ 	rq->prev_steal_time_rq = 0;
+ #endif
+ }