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-rw-r--r--meta-eas/recipes-kernel/linux/linux-renesas/0015-sched-Extend-scheduler-s-asym-packing.patch208
1 files changed, 208 insertions, 0 deletions
diff --git a/meta-eas/recipes-kernel/linux/linux-renesas/0015-sched-Extend-scheduler-s-asym-packing.patch b/meta-eas/recipes-kernel/linux/linux-renesas/0015-sched-Extend-scheduler-s-asym-packing.patch
new file mode 100644
index 0000000..6d2b9de
--- /dev/null
+++ b/meta-eas/recipes-kernel/linux/linux-renesas/0015-sched-Extend-scheduler-s-asym-packing.patch
@@ -0,0 +1,208 @@
+From e467f39a4c96c4a6f96be66a9224807fe9b7346e Mon Sep 17 00:00:00 2001
+From: Tim Chen <tim.c.chen@linux.intel.com>
+Date: Tue, 22 Nov 2016 12:23:53 -0800
+Subject: [PATCH 15/92] sched: Extend scheduler's asym packing
+
+We generalize the scheduler's asym packing to provide an ordering
+of the cpu beyond just the cpu number. This allows the use of the
+ASYM_PACKING scheduler machinery to move loads to preferred CPU in a
+sched domain. The preference is defined with the cpu priority
+given by arch_asym_cpu_priority(cpu).
+
+We also record the most preferred cpu in a sched group when
+we build the cpu's capacity for fast lookup of preferred cpu
+during load balancing.
+
+Co-developed-by: Peter Zijlstra (Intel) <peterz@infradead.org>
+Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
+Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
+Cc: linux-pm@vger.kernel.org
+Cc: jolsa@redhat.com
+Cc: rjw@rjwysocki.net
+Cc: linux-acpi@vger.kernel.org
+Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
+Cc: bp@suse.de
+Link: http://lkml.kernel.org/r/0e73ae12737dfaafa46c07066cc7c5d3f1675e46.1479844244.git.tim.c.chen@linux.intel.com
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+
+(cherry picked from commit afe06efdf07c12fd9370d5cce5383398cedf6c90)
+Signed-off-by: Gaku Inami <gaku.inami.xw@bp.renesas.com>
+---
+ include/linux/sched.h | 2 ++
+ kernel/sched/core.c | 15 +++++++++++++++
+ kernel/sched/fair.c | 53 ++++++++++++++++++++++++++++++++++-----------------
+ kernel/sched/sched.h | 6 ++++++
+ 4 files changed, 59 insertions(+), 17 deletions(-)
+
+diff --git a/include/linux/sched.h b/include/linux/sched.h
+index e9c009d..2e3c2a1 100644
+--- a/include/linux/sched.h
++++ b/include/linux/sched.h
+@@ -1057,6 +1057,8 @@ static inline int cpu_numa_flags(void)
+ }
+ #endif
+
++extern int arch_asym_cpu_priority(int cpu);
++
+ struct sched_domain_attr {
+ int relax_domain_level;
+ };
+diff --git a/kernel/sched/core.c b/kernel/sched/core.c
+index 391d6c9..209d2ea 100644
+--- a/kernel/sched/core.c
++++ b/kernel/sched/core.c
+@@ -6302,7 +6302,22 @@ static void init_sched_groups_capacity(int cpu, struct sched_domain *sd)
+ WARN_ON(!sg);
+
+ do {
++ int cpu, max_cpu = -1;
++
+ sg->group_weight = cpumask_weight(sched_group_cpus(sg));
++
++ if (!(sd->flags & SD_ASYM_PACKING))
++ goto next;
++
++ for_each_cpu(cpu, sched_group_cpus(sg)) {
++ if (max_cpu < 0)
++ max_cpu = cpu;
++ else if (sched_asym_prefer(cpu, max_cpu))
++ max_cpu = cpu;
++ }
++ sg->asym_prefer_cpu = max_cpu;
++
++next:
+ sg = sg->next;
+ } while (sg != sd->groups);
+
+diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
+index aa47589..18d9e75 100644
+--- a/kernel/sched/fair.c
++++ b/kernel/sched/fair.c
+@@ -97,6 +97,16 @@
+
+ const_debug unsigned int sysctl_sched_migration_cost = 500000UL;
+
++#ifdef CONFIG_SMP
++/*
++ * For asym packing, by default the lower numbered cpu has higher priority.
++ */
++int __weak arch_asym_cpu_priority(int cpu)
++{
++ return -cpu;
++}
++#endif
++
+ #ifdef CONFIG_CFS_BANDWIDTH
+ /*
+ * Amount of runtime to allocate from global (tg) to local (per-cfs_rq) pool
+@@ -7388,16 +7398,18 @@ static bool update_sd_pick_busiest(struct lb_env *env,
+ if (env->idle == CPU_NOT_IDLE)
+ return true;
+ /*
+- * ASYM_PACKING needs to move all the work to the lowest
+- * numbered CPUs in the group, therefore mark all groups
+- * higher than ourself as busy.
++ * ASYM_PACKING needs to move all the work to the highest
++ * prority CPUs in the group, therefore mark all groups
++ * of lower priority than ourself as busy.
+ */
+- if (sgs->sum_nr_running && env->dst_cpu < group_first_cpu(sg)) {
++ if (sgs->sum_nr_running &&
++ sched_asym_prefer(env->dst_cpu, sg->asym_prefer_cpu)) {
+ if (!sds->busiest)
+ return true;
+
+- /* Prefer to move from highest possible cpu's work */
+- if (group_first_cpu(sds->busiest) < group_first_cpu(sg))
++ /* Prefer to move from lowest priority cpu's work */
++ if (sched_asym_prefer(sds->busiest->asym_prefer_cpu,
++ sg->asym_prefer_cpu))
+ return true;
+ }
+
+@@ -7549,8 +7561,8 @@ static int check_asym_packing(struct lb_env *env, struct sd_lb_stats *sds)
+ if (!sds->busiest)
+ return 0;
+
+- busiest_cpu = group_first_cpu(sds->busiest);
+- if (env->dst_cpu > busiest_cpu)
++ busiest_cpu = sds->busiest->asym_prefer_cpu;
++ if (sched_asym_prefer(busiest_cpu, env->dst_cpu))
+ return 0;
+
+ env->imbalance = DIV_ROUND_CLOSEST(
+@@ -7888,10 +7900,11 @@ static int need_active_balance(struct lb_env *env)
+
+ /*
+ * ASYM_PACKING needs to force migrate tasks from busy but
+- * higher numbered CPUs in order to pack all tasks in the
+- * lowest numbered CPUs.
++ * lower priority CPUs in order to pack all tasks in the
++ * highest priority CPUs.
+ */
+- if ((sd->flags & SD_ASYM_PACKING) && env->src_cpu > env->dst_cpu)
++ if ((sd->flags & SD_ASYM_PACKING) &&
++ sched_asym_prefer(env->dst_cpu, env->src_cpu))
+ return 1;
+ }
+
+@@ -8740,7 +8753,7 @@ static inline bool nohz_kick_needed(struct rq *rq)
+ unsigned long now = jiffies;
+ struct sched_domain_shared *sds;
+ struct sched_domain *sd;
+- int nr_busy, cpu = rq->cpu;
++ int nr_busy, i, cpu = rq->cpu;
+ bool kick = false;
+
+ if (unlikely(rq->idle_balance))
+@@ -8791,12 +8804,18 @@ static inline bool nohz_kick_needed(struct rq *rq)
+ }
+
+ sd = rcu_dereference(per_cpu(sd_asym, cpu));
+- if (sd && (cpumask_first_and(nohz.idle_cpus_mask,
+- sched_domain_span(sd)) < cpu)) {
+- kick = true;
+- goto unlock;
+- }
++ if (sd) {
++ for_each_cpu(i, sched_domain_span(sd)) {
++ if (i == cpu ||
++ !cpumask_test_cpu(i, nohz.idle_cpus_mask))
++ continue;
+
++ if (sched_asym_prefer(i, cpu)) {
++ kick = true;
++ goto unlock;
++ }
++ }
++ }
+ unlock:
+ rcu_read_unlock();
+ return kick;
+diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
+index d7e3931..7b34c78 100644
+--- a/kernel/sched/sched.h
++++ b/kernel/sched/sched.h
+@@ -540,6 +540,11 @@ struct dl_rq {
+
+ #ifdef CONFIG_SMP
+
++static inline bool sched_asym_prefer(int a, int b)
++{
++ return arch_asym_cpu_priority(a) > arch_asym_cpu_priority(b);
++}
++
+ /*
+ * We add the notion of a root-domain which will be used to define per-domain
+ * variables. Each exclusive cpuset essentially defines an island domain by
+@@ -908,6 +913,7 @@ struct sched_group {
+
+ unsigned int group_weight;
+ struct sched_group_capacity *sgc;
++ int asym_prefer_cpu; /* cpu of highest priority in group */
+
+ /*
+ * The CPUs this group covers.
+--
+1.9.1
+