2019-07-22 18:25:32

by Rik van Riel

[permalink] [raw]
Subject: [PATCH 10/14] sched,fair: add helper functions for flattened runqueue

Add helper functions to make the flattened runqueue patch a little smaller.

The task_se_h_weight function is similar to task_se_h_load, but scales the
task weight by the group weight, without taking the task's duty cycle into
account.

The task_se_in_cgroup helper is functionally identical to parent_entity,
but directly calling a function with that name obscures what the other
code is trying to use it for, and would make the code harder to understand.

Signed-off-by: Rik van Riel <[email protected]>
---
kernel/sched/fair.c | 31 +++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index c944729423bd..6073fabb171b 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -243,6 +243,7 @@ static u64 __calc_delta(u64 delta_exec, unsigned long weight, struct load_weight

const struct sched_class fair_sched_class;
static unsigned long task_se_h_load(struct sched_entity *se);
+static unsigned long task_se_h_weight(struct sched_entity *se);

/**************************************************************
* CFS operations on generic schedulable entities:
@@ -431,6 +432,12 @@ static inline struct sched_entity *parent_entity(struct sched_entity *se)
return se->parent;
}

+/* Is this (task) sched_entity in a non-root cgroup? */
+static inline bool task_se_in_cgroup(struct sched_entity *se)
+{
+ return parent_entity(se);
+}
+
static void
find_matching_se(struct sched_entity **se, struct sched_entity **pse)
{
@@ -513,6 +520,11 @@ static inline struct sched_entity *parent_entity(struct sched_entity *se)
return NULL;
}

+static inline bool task_se_in_cgroup(struct sched_entity *se)
+{
+ return false;
+}
+
static inline void
find_matching_se(struct sched_entity **se, struct sched_entity **pse)
{
@@ -7835,6 +7847,20 @@ static void update_cfs_rq_h_load(struct cfs_rq *cfs_rq)
}
}

+static unsigned long task_se_h_weight(struct sched_entity *se)
+{
+ struct cfs_rq *cfs_rq;
+
+ if (!task_se_in_cgroup(se))
+ return se->load.weight;
+
+ cfs_rq = group_cfs_rq_of_parent(se);
+ update_cfs_rq_h_load(cfs_rq);
+
+ /* Reduce the load.weight by the h_load of the group the task is in. */
+ return (cfs_rq->h_load * se->load.weight) >> SCHED_FIXEDPOINT_SHIFT;
+}
+
static unsigned long task_se_h_load(struct sched_entity *se)
{
struct cfs_rq *cfs_rq = group_cfs_rq_of_parent(se);
@@ -7871,6 +7897,11 @@ static unsigned long task_se_h_load(struct sched_entity *se)
{
return se->avg.load_avg;
}
+
+static unsigned long task_se_h_weight(struct sched_entity *se)
+{
+ return se->load.weight;
+}
#endif

/********** Helpers for find_busiest_group ************************/
--
2.20.1