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Message-ID: <20160311125746.42e35ea8@canb.auug.org.au>
Date: Fri, 11 Mar 2016 12:57:46 +1100
From: Stephen Rothwell <sfr@...b.auug.org.au>
To: Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...e.hu>,
"H. Peter Anvin" <hpa@...or.com>,
Peter Zijlstra <peterz@...radead.org>,
"Rafael J. Wysocki" <rjw@...ysocki.net>
Cc: linux-next@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: linux-next: manual merge of the tip tree with the pm tree
Hi all,
Today's linux-next merge of the tip tree got a conflict in:
kernel/sched/sched.h
between commit:
adaf9fcd1369 ("cpufreq: Move scheduler-related code to the sched directory")
from the pm tree and commit:
e9532e69b8d1 ("sched/cputime: Fix steal time accounting vs. CPU hotplug")
from the tip tree.
I fixed it up (see below) and can carry the fix as necessary (no action
is required).
--
Cheers,
Stephen Rothwell
diff --cc kernel/sched/sched.h
index faf7e2758dd0,e6d4a3fa3660..000000000000
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@@ -1739,50 -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
+ }
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