[PATCH v2 2/6] sched/fair: Remove SCHED_LOAD_SHIFT and SCHED_LOAD_SCALE

From: Yuyang Du
Date: Thu Oct 22 2015 - 03:13:18 EST


After cleaning up the sched metrics, these two definitions that cause
ambiguity are not needed any more. Use NICE_0_LOAD_SHIFT and NICE_0_LOAD
instead (the names suggest clearly who they are).

Suggested-by: Ben Segall <bsegall@xxxxxxxxxx>
Signed-off-by: Yuyang Du <yuyang.du@xxxxxxxxx>
---
kernel/sched/fair.c | 4 ++--
kernel/sched/sched.h | 22 +++++++++++-----------
2 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index c61fd8e..19d34a5 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -682,7 +682,7 @@ void init_entity_runnable_average(struct sched_entity *se)
sa->period_contrib = 1023;
sa->load_avg = scale_load_down(se->load.weight);
sa->load_sum = sa->load_avg * LOAD_AVG_MAX;
- sa->util_avg = scale_load_down(SCHED_LOAD_SCALE);
+ sa->util_avg = SCHED_CAPACITY_SCALE;
sa->util_sum = sa->util_avg * LOAD_AVG_MAX;
/* when this task enqueue'ed, it will contribute to its cfs_rq's load_avg */
}
@@ -6651,7 +6651,7 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
if (busiest->group_type == group_overloaded &&
local->group_type == group_overloaded) {
load_above_capacity = busiest->sum_nr_running *
- SCHED_LOAD_SCALE;
+ scale_load_down(NICE_0_LOAD);
if (load_above_capacity > busiest->group_capacity)
load_above_capacity -= busiest->group_capacity;
else
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 61a5858..ded3a6d 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -53,25 +53,25 @@ static inline void update_cpu_load_active(struct rq *this_rq) { }
* increased costs.
*/
#if 0 /* BITS_PER_LONG > 32 -- currently broken: it increases power usage under light load */
-# define SCHED_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT + SCHED_FIXEDPOINT_SHIFT)
+# define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT + SCHED_FIXEDPOINT_SHIFT)
# define scale_load(w) ((w) << SCHED_FIXEDPOINT_SHIFT)
# define scale_load_down(w) ((w) >> SCHED_FIXEDPOINT_SHIFT)
#else
-# define SCHED_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT)
+# define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT)
# define scale_load(w) (w)
# define scale_load_down(w) (w)
#endif

-#define SCHED_LOAD_SCALE (1L << SCHED_LOAD_SHIFT)
-
/*
- * NICE_0's weight (visible to user) and its load (invisible to user) have
- * independent ranges, but they should be well calibrated. We use scale_load()
- * and scale_load_down(w) to convert between them, the following must be true:
- * scale_load(prio_to_weight[20]) == NICE_0_LOAD
+ * Task weight (visible to user) and its load (invisible to user) have
+ * independent resolution, but they should be well calibrated. We use
+ * scale_load() and scale_load_down(w) to convert between them. The
+ * following must be true:
+ *
+ * scale_load(prio_to_weight[USER_PRIO(NICE_TO_PRIO(0))]) == NICE_0_LOAD
+ *
*/
-#define NICE_0_LOAD SCHED_LOAD_SCALE
-#define NICE_0_SHIFT SCHED_LOAD_SHIFT
+#define NICE_0_LOAD (1L << NICE_0_LOAD_SHIFT)

/*
* Single value that decides SCHED_DEADLINE internal math precision.
@@ -850,7 +850,7 @@ DECLARE_PER_CPU(struct sched_domain *, sd_asym);
struct sched_group_capacity {
atomic_t ref;
/*
- * CPU capacity of this group, SCHED_LOAD_SCALE being max capacity
+ * CPU capacity of this group, SCHED_CAPACITY_SCALE being max capacity
* for a single CPU.
*/
unsigned int capacity;
--
2.1.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/