sched: per-cpu mostly_idle threshold

sched_mostly_idle_load and sched_mostly_idle_nr_run knobs help pack
tasks on cpus to some extent. In some cases, it may be desirable to
have different packing limits for different cpus. For example, pack to
a higher limit on high-performance cpus compared to power-efficient
cpus.

This patch removes the global mostly_idle tunables and makes them
per-cpu, thus letting task packing behavior to be controlled in a
fine-grained manner.

Change-Id: Ifc254cda34b928eae9d6c342ce4c0f64e531e6c2
Signed-off-by: Srivatsa Vaddagiri <vatsa@codeaurora.org>

1 files changed, 95 insertions, 0 deletions

diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 91bbb1959d8d..763fd00c697b 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -180,10 +180,102 @@ static struct attribute_group crash_note_cpu_attr_group = {
 };
 #endif
 
+#ifdef CONFIG_SCHED_HMP
+static ssize_t show_sched_mostly_idle_load(struct device *dev,
+		 struct device_attribute *attr, char *buf)
+{
+	struct cpu *cpu = container_of(dev, struct cpu, dev);
+	ssize_t rc;
+	int cpunum;
+	int mostly_idle_pct;
+
+	cpunum = cpu->dev.id;
+
+	mostly_idle_pct = sched_get_cpu_mostly_idle_load(cpunum);
+
+	rc = snprintf(buf, PAGE_SIZE-2, "%d\n", mostly_idle_pct);
+
+	return rc;
+}
+
+static ssize_t __ref store_sched_mostly_idle_load(struct device *dev,
+				  struct device_attribute *attr,
+				  const char *buf, size_t count)
+{
+	struct cpu *cpu = container_of(dev, struct cpu, dev);
+	int cpuid = cpu->dev.id;
+	int mostly_idle_load, err;
+
+	err = kstrtoint(strstrip((char *)buf), 0, &mostly_idle_load);
+	if (err)
+		return err;
+
+	err = sched_set_cpu_mostly_idle_load(cpuid, mostly_idle_load);
+	if (err >= 0)
+		err = count;
+
+	return err;
+}
+
+static ssize_t show_sched_mostly_idle_nr_run(struct device *dev,
+		 struct device_attribute *attr, char *buf)
+{
+	struct cpu *cpu = container_of(dev, struct cpu, dev);
+	ssize_t rc;
+	int cpunum;
+	int mostly_idle_nr_run;
+
+	cpunum = cpu->dev.id;
+
+	mostly_idle_nr_run = sched_get_cpu_mostly_idle_nr_run(cpunum);
+
+	rc = snprintf(buf, PAGE_SIZE-2, "%d\n", mostly_idle_nr_run);
+
+	return rc;
+}
+
+static ssize_t __ref store_sched_mostly_idle_nr_run(struct device *dev,
+				  struct device_attribute *attr,
+				  const char *buf, size_t count)
+{
+	struct cpu *cpu = container_of(dev, struct cpu, dev);
+	int cpuid = cpu->dev.id;
+	int mostly_idle_nr_run, err;
+
+	err = kstrtoint(strstrip((char *)buf), 0, &mostly_idle_nr_run);
+	if (err)
+		return err;
+
+	err = sched_set_cpu_mostly_idle_nr_run(cpuid, mostly_idle_nr_run);
+	if (err >= 0)
+		err = count;
+
+	return err;
+}
+
+static DEVICE_ATTR(sched_mostly_idle_load, 0664, show_sched_mostly_idle_load,
+						store_sched_mostly_idle_load);
+static DEVICE_ATTR(sched_mostly_idle_nr_run, 0664,
+		show_sched_mostly_idle_nr_run, store_sched_mostly_idle_nr_run);
+
+static struct attribute *hmp_sched_cpu_attrs[] = {
+	&dev_attr_sched_mostly_idle_load.attr,
+	&dev_attr_sched_mostly_idle_nr_run.attr,
+	NULL
+};
+
+static struct attribute_group sched_hmp_cpu_attr_group = {
+	.attrs = hmp_sched_cpu_attrs,
+};
+
+#endif	/* CONFIG_SCHED_HMP */
 static const struct attribute_group *common_cpu_attr_groups[] = {
 #ifdef CONFIG_KEXEC
 	&crash_note_cpu_attr_group,
 #endif
+#ifdef CONFIG_SCHED_HMP
+	&sched_hmp_cpu_attr_group,
+#endif
 	NULL
 };
 
@@ -191,6 +283,9 @@ static const struct attribute_group *hotplugable_cpu_attr_groups[] = {
 #ifdef CONFIG_KEXEC
 	&crash_note_cpu_attr_group,
 #endif
+#ifdef CONFIG_SCHED_HMP
+	&sched_hmp_cpu_attr_group,
+#endif
 	NULL
 };