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authorMark Brown <broonie@linaro.org>2013-11-21 11:58:31 +0000
committerMark Brown <broonie@linaro.org>2013-11-21 11:58:31 +0000
commite7004f3e7fd90e611362b78ac64e357ee80c177c (patch)
tree5fd2ee397309fd82be54f895e80d5a46f2e77964 /kernel
parentd09f944ad56e02d4a27c111f9e84e008028c3304 (diff)
parentf5be72980bc321f3491377861835c343cc27af0d (diff)
downloadvexpress-lsk-e7004f3e7fd90e611362b78ac64e357ee80c177c.tar.gz
Merge branch 'for-lsk' of git://git.linaro.org/arm/big.LITTLE/mp into lsk-v3.10-big.LITTLE
Diffstat (limited to 'kernel')
-rw-r--r--kernel/sched/fair.c218
1 files changed, 177 insertions, 41 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 66b5b30159f..c7d808ee0a3 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -31,7 +31,6 @@
#include <linux/task_work.h>
#include <trace/events/sched.h>
-#ifdef CONFIG_HMP_VARIABLE_SCALE
#include <linux/sysfs.h>
#include <linux/vmalloc.h>
#ifdef CONFIG_HMP_FREQUENCY_INVARIANT_SCALE
@@ -40,7 +39,6 @@
*/
#include <linux/cpufreq.h>
#endif /* CONFIG_HMP_FREQUENCY_INVARIANT_SCALE */
-#endif /* CONFIG_HMP_VARIABLE_SCALE */
#include "sched.h"
@@ -1212,8 +1210,6 @@ static u32 __compute_runnable_contrib(u64 n)
return contrib + runnable_avg_yN_sum[n];
}
-#ifdef CONFIG_HMP_VARIABLE_SCALE
-
#define HMP_VARIABLE_SCALE_SHIFT 16ULL
struct hmp_global_attr {
struct attribute attr;
@@ -1224,6 +1220,7 @@ struct hmp_global_attr {
int *value;
int (*to_sysfs)(int);
int (*from_sysfs)(int);
+ ssize_t (*to_sysfs_text)(char *buf, int buf_size);
};
#define HMP_DATA_SYSFS_MAX 8
@@ -1294,7 +1291,6 @@ struct cpufreq_extents {
static struct cpufreq_extents freq_scale[CONFIG_NR_CPUS];
#endif /* CONFIG_HMP_FREQUENCY_INVARIANT_SCALE */
-#endif /* CONFIG_HMP_VARIABLE_SCALE */
/* We can represent the historical contribution to runnable average as the
* coefficients of a geometric series. To do this we sub-divide our runnable
@@ -1340,9 +1336,8 @@ static __always_inline int __update_entity_runnable_avg(u64 now,
#endif /* CONFIG_HMP_FREQUENCY_INVARIANT_SCALE */
delta = now - sa->last_runnable_update;
-#ifdef CONFIG_HMP_VARIABLE_SCALE
+
delta = hmp_variable_scale_convert(delta);
-#endif
/*
* This should only happen when time goes backwards, which it
* unfortunately does during sched clock init when we swap over to TSC.
@@ -3842,7 +3837,6 @@ static inline void hmp_next_down_delay(struct sched_entity *se, int cpu)
cpu_rq(cpu)->avg.hmp_last_up_migration = 0;
}
-#ifdef CONFIG_HMP_VARIABLE_SCALE
/*
* Heterogenous multiprocessor (HMP) optimizations
*
@@ -3875,27 +3869,35 @@ static inline void hmp_next_down_delay(struct sched_entity *se, int cpu)
* The scale factor hmp_data.multiplier is a fixed point
* number: (32-HMP_VARIABLE_SCALE_SHIFT).HMP_VARIABLE_SCALE_SHIFT
*/
-static u64 hmp_variable_scale_convert(u64 delta)
+static inline u64 hmp_variable_scale_convert(u64 delta)
{
+#ifdef CONFIG_HMP_VARIABLE_SCALE
u64 high = delta >> 32ULL;
u64 low = delta & 0xffffffffULL;
low *= hmp_data.multiplier;
high *= hmp_data.multiplier;
return (low >> HMP_VARIABLE_SCALE_SHIFT)
+ (high << (32ULL - HMP_VARIABLE_SCALE_SHIFT));
+#else
+ return delta;
+#endif
}
static ssize_t hmp_show(struct kobject *kobj,
struct attribute *attr, char *buf)
{
- ssize_t ret = 0;
struct hmp_global_attr *hmp_attr =
container_of(attr, struct hmp_global_attr, attr);
- int temp = *(hmp_attr->value);
+ int temp;
+
+ if (hmp_attr->to_sysfs_text != NULL)
+ return hmp_attr->to_sysfs_text(buf, PAGE_SIZE);
+
+ temp = *(hmp_attr->value);
if (hmp_attr->to_sysfs != NULL)
temp = hmp_attr->to_sysfs(temp);
- ret = sprintf(buf, "%d\n", temp);
- return ret;
+
+ return (ssize_t)sprintf(buf, "%d\n", temp);
}
static ssize_t hmp_store(struct kobject *a, struct attribute *attr,
@@ -3924,11 +3926,31 @@ static ssize_t hmp_store(struct kobject *a, struct attribute *attr,
return ret;
}
+static ssize_t hmp_print_domains(char *outbuf, int outbufsize)
+{
+ char buf[64];
+ const char nospace[] = "%s", space[] = " %s";
+ const char *fmt = nospace;
+ struct hmp_domain *domain;
+ struct list_head *pos;
+ int outpos = 0;
+ list_for_each(pos, &hmp_domains) {
+ domain = list_entry(pos, struct hmp_domain, hmp_domains);
+ if (cpumask_scnprintf(buf, 64, &domain->possible_cpus)) {
+ outpos += sprintf(outbuf+outpos, fmt, buf);
+ fmt = space;
+ }
+ }
+ strcat(outbuf, "\n");
+ return outpos+1;
+}
+
+#ifdef CONFIG_HMP_VARIABLE_SCALE
static int hmp_period_tofrom_sysfs(int value)
{
return (LOAD_AVG_PERIOD << HMP_VARIABLE_SCALE_SHIFT) / value;
}
-
+#endif
/* max value for threshold is 1024 */
static int hmp_theshold_from_sysfs(int value)
{
@@ -3936,9 +3958,10 @@ static int hmp_theshold_from_sysfs(int value)
return -1;
return value;
}
-#ifdef CONFIG_HMP_FREQUENCY_INVARIANT_SCALE
-/* freqinvar control is only 0,1 off/on */
-static int hmp_freqinvar_from_sysfs(int value)
+#if defined(CONFIG_SCHED_HMP_LITTLE_PACKING) || \
+ defined(CONFIG_HMP_FREQUENCY_INVARIANT_SCALE)
+/* toggle control is only 0,1 off/on */
+static int hmp_toggle_from_sysfs(int value)
{
if (value < 0 || value > 1)
return -1;
@@ -3958,7 +3981,9 @@ static void hmp_attr_add(
const char *name,
int *value,
int (*to_sysfs)(int),
- int (*from_sysfs)(int))
+ int (*from_sysfs)(int),
+ ssize_t (*to_sysfs_text)(char *, int),
+ umode_t mode)
{
int i = 0;
while (hmp_data.attributes[i] != NULL) {
@@ -3966,13 +3991,17 @@ static void hmp_attr_add(
if (i >= HMP_DATA_SYSFS_MAX)
return;
}
- hmp_data.attr[i].attr.mode = 0644;
+ if (mode)
+ hmp_data.attr[i].attr.mode = mode;
+ else
+ hmp_data.attr[i].attr.mode = 0644;
hmp_data.attr[i].show = hmp_show;
hmp_data.attr[i].store = hmp_store;
hmp_data.attr[i].attr.name = name;
hmp_data.attr[i].value = value;
hmp_data.attr[i].to_sysfs = to_sysfs;
hmp_data.attr[i].from_sysfs = from_sysfs;
+ hmp_data.attr[i].to_sysfs_text = to_sysfs_text;
hmp_data.attributes[i] = &hmp_data.attr[i].attr;
hmp_data.attributes[i + 1] = NULL;
}
@@ -3981,40 +4010,59 @@ static int hmp_attr_init(void)
{
int ret;
memset(&hmp_data, sizeof(hmp_data), 0);
+ hmp_attr_add("hmp_domains",
+ NULL,
+ NULL,
+ NULL,
+ hmp_print_domains,
+ 0444);
+ hmp_attr_add("up_threshold",
+ &hmp_up_threshold,
+ NULL,
+ hmp_theshold_from_sysfs,
+ NULL,
+ 0);
+ hmp_attr_add("down_threshold",
+ &hmp_down_threshold,
+ NULL,
+ hmp_theshold_from_sysfs,
+ NULL,
+ 0);
+#ifdef CONFIG_HMP_VARIABLE_SCALE
/* by default load_avg_period_ms == LOAD_AVG_PERIOD
* meaning no change
*/
hmp_data.multiplier = hmp_period_tofrom_sysfs(LOAD_AVG_PERIOD);
-
hmp_attr_add("load_avg_period_ms",
&hmp_data.multiplier,
hmp_period_tofrom_sysfs,
- hmp_period_tofrom_sysfs);
- hmp_attr_add("up_threshold",
- &hmp_up_threshold,
- NULL,
- hmp_theshold_from_sysfs);
- hmp_attr_add("down_threshold",
- &hmp_down_threshold,
+ hmp_period_tofrom_sysfs,
NULL,
- hmp_theshold_from_sysfs);
+ 0);
+#endif
#ifdef CONFIG_HMP_FREQUENCY_INVARIANT_SCALE
/* default frequency-invariant scaling ON */
hmp_data.freqinvar_load_scale_enabled = 1;
hmp_attr_add("frequency_invariant_load_scale",
&hmp_data.freqinvar_load_scale_enabled,
NULL,
- hmp_freqinvar_from_sysfs);
+ hmp_toggle_from_sysfs,
+ NULL,
+ 0);
#endif
#ifdef CONFIG_SCHED_HMP_LITTLE_PACKING
hmp_attr_add("packing_enable",
&hmp_packing_enabled,
NULL,
- hmp_freqinvar_from_sysfs);
+ hmp_toggle_from_sysfs,
+ NULL,
+ 0);
hmp_attr_add("packing_limit",
&hmp_full_threshold,
NULL,
- hmp_packing_from_sysfs);
+ hmp_packing_from_sysfs,
+ NULL,
+ 0);
#endif
hmp_data.attr_group.name = "hmp";
hmp_data.attr_group.attrs = hmp_data.attributes;
@@ -4023,7 +4071,6 @@ static int hmp_attr_init(void)
return 0;
}
late_initcall(hmp_attr_init);
-#endif /* CONFIG_HMP_VARIABLE_SCALE */
/*
* return the load of the lowest-loaded CPU in a given HMP domain
* min_cpu optionally points to an int to receive the CPU.
@@ -6914,6 +6961,69 @@ out_unlock:
return 0;
}
+/*
+ * Move task in a runnable state to another CPU.
+ *
+ * Tailored on 'active_load_balance_stop_cpu' with slight
+ * modification to locking and pre-transfer checks. Note
+ * rq->lock must be held before calling.
+ */
+static void hmp_migrate_runnable_task(struct rq *rq)
+{
+ struct sched_domain *sd;
+ int src_cpu = cpu_of(rq);
+ struct rq *src_rq = rq;
+ int dst_cpu = rq->push_cpu;
+ struct rq *dst_rq = cpu_rq(dst_cpu);
+ struct task_struct *p = rq->migrate_task;
+ /*
+ * One last check to make sure nobody else is playing
+ * with the source rq.
+ */
+ if (src_rq->active_balance)
+ return;
+
+ if (src_rq->nr_running <= 1)
+ return;
+
+ if (task_rq(p) != src_rq)
+ return;
+ /*
+ * Not sure if this applies here but one can never
+ * be too cautious
+ */
+ BUG_ON(src_rq == dst_rq);
+
+ double_lock_balance(src_rq, dst_rq);
+
+ rcu_read_lock();
+ for_each_domain(dst_cpu, sd) {
+ if (cpumask_test_cpu(src_cpu, sched_domain_span(sd)))
+ break;
+ }
+
+ if (likely(sd)) {
+ struct lb_env env = {
+ .sd = sd,
+ .dst_cpu = dst_cpu,
+ .dst_rq = dst_rq,
+ .src_cpu = src_cpu,
+ .src_rq = src_rq,
+ .idle = CPU_IDLE,
+ };
+
+ schedstat_inc(sd, alb_count);
+
+ if (move_specific_task(&env, p))
+ schedstat_inc(sd, alb_pushed);
+ else
+ schedstat_inc(sd, alb_failed);
+ }
+
+ rcu_read_unlock();
+ double_unlock_balance(src_rq, dst_rq);
+}
+
static DEFINE_SPINLOCK(hmp_force_migration);
/*
@@ -6926,13 +7036,14 @@ static void hmp_force_up_migration(int this_cpu)
struct sched_entity *curr, *orig;
struct rq *target;
unsigned long flags;
- unsigned int force;
+ unsigned int force, got_target;
struct task_struct *p;
if (!spin_trylock(&hmp_force_migration))
return;
for_each_online_cpu(cpu) {
force = 0;
+ got_target = 0;
target = cpu_rq(cpu);
raw_spin_lock_irqsave(&target->lock, flags);
curr = target->cfs.curr;
@@ -6955,15 +7066,14 @@ static void hmp_force_up_migration(int this_cpu)
if (hmp_up_migration(cpu, &target_cpu, curr)) {
if (!target->active_balance) {
get_task_struct(p);
- target->active_balance = 1;
target->push_cpu = target_cpu;
target->migrate_task = p;
- force = 1;
+ got_target = 1;
trace_sched_hmp_migrate(p, target->push_cpu, HMP_MIGRATE_FORCE);
hmp_next_up_delay(&p->se, target->push_cpu);
}
}
- if (!force && !target->active_balance) {
+ if (!got_target && !target->active_balance) {
/*
* For now we just check the currently running task.
* Selecting the lightest task for offloading will
@@ -6974,14 +7084,29 @@ static void hmp_force_up_migration(int this_cpu)
target->push_cpu = hmp_offload_down(cpu, curr);
if (target->push_cpu < NR_CPUS) {
get_task_struct(p);
- target->active_balance = 1;
target->migrate_task = p;
- force = 1;
+ got_target = 1;
trace_sched_hmp_migrate(p, target->push_cpu, HMP_MIGRATE_OFFLOAD);
hmp_next_down_delay(&p->se, target->push_cpu);
}
}
+ /*
+ * We have a target with no active_balance. If the task
+ * is not currently running move it, otherwise let the
+ * CPU stopper take care of it.
+ */
+ if (got_target && !target->active_balance) {
+ if (!task_running(target, p)) {
+ trace_sched_hmp_migrate_force_running(p, 0);
+ hmp_migrate_runnable_task(target);
+ } else {
+ target->active_balance = 1;
+ force = 1;
+ }
+ }
+
raw_spin_unlock_irqrestore(&target->lock, flags);
+
if (force)
stop_one_cpu_nowait(cpu_of(target),
hmp_active_task_migration_cpu_stop,
@@ -7001,7 +7126,7 @@ static unsigned int hmp_idle_pull(int this_cpu)
int cpu;
struct sched_entity *curr, *orig;
struct hmp_domain *hmp_domain = NULL;
- struct rq *target, *rq;
+ struct rq *target = NULL, *rq;
unsigned long flags, ratio = 0;
unsigned int force = 0;
struct task_struct *p = NULL;
@@ -7053,14 +7178,25 @@ static unsigned int hmp_idle_pull(int this_cpu)
raw_spin_lock_irqsave(&target->lock, flags);
if (!target->active_balance && task_rq(p) == target) {
get_task_struct(p);
- target->active_balance = 1;
target->push_cpu = this_cpu;
target->migrate_task = p;
- force = 1;
trace_sched_hmp_migrate(p, target->push_cpu, HMP_MIGRATE_IDLE_PULL);
hmp_next_up_delay(&p->se, target->push_cpu);
+ /*
+ * if the task isn't running move it right away.
+ * Otherwise setup the active_balance mechanic and let
+ * the CPU stopper do its job.
+ */
+ if (!task_running(target, p)) {
+ trace_sched_hmp_migrate_idle_running(p, 0);
+ hmp_migrate_runnable_task(target);
+ } else {
+ target->active_balance = 1;
+ force = 1;
+ }
}
raw_spin_unlock_irqrestore(&target->lock, flags);
+
if (force) {
stop_one_cpu_nowait(cpu_of(target),
hmp_idle_pull_cpu_stop,