[PATCH 12/15] sched,fair: flatten update_curr functionality

From: Rik van Riel
Date: Wed Aug 21 2019 - 22:18:45 EST


Make it clear that update_curr only works on tasks any more.

There is no need for task_tick_fair to call it on every sched entity up
the hierarchy, so move the call out of entity_tick.

Signed-off-by: Rik van Riel <riel@xxxxxxxxxxx>`
Signed-off-by: Rik van Riel <riel@xxxxxxxxxxx>
---
kernel/sched/fair.c | 24 +++++++++++-------------
1 file changed, 11 insertions(+), 13 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index fa8e88731821..5cfa3dbeba49 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -872,10 +872,11 @@ static void update_tg_load_avg(struct cfs_rq *cfs_rq, int force)
static void update_curr(struct cfs_rq *cfs_rq)
{
struct sched_entity *curr = cfs_rq->curr;
+ struct task_struct *curtask;
u64 now = rq_clock_task(rq_of(cfs_rq));
u64 delta_exec;

- if (unlikely(!curr))
+ if (unlikely(!curr) || !entity_is_task(curr))
return;

delta_exec = now - curr->exec_start;
@@ -893,13 +894,10 @@ static void update_curr(struct cfs_rq *cfs_rq)
curr->vruntime += calc_delta_fair(delta_exec, curr);
update_min_vruntime(cfs_rq);

- if (entity_is_task(curr)) {
- struct task_struct *curtask = task_of(curr);
-
- trace_sched_stat_runtime(curtask, delta_exec, curr->vruntime);
- cgroup_account_cputime(curtask, delta_exec);
- account_group_exec_runtime(curtask, delta_exec);
- }
+ curtask = task_of(curr);
+ trace_sched_stat_runtime(curtask, delta_exec, curr->vruntime);
+ cgroup_account_cputime(curtask, delta_exec);
+ account_group_exec_runtime(curtask, delta_exec);

account_cfs_rq_runtime(cfs_rq, delta_exec);
}
@@ -4196,11 +4194,6 @@ static void put_prev_entity(struct cfs_rq *cfs_rq, struct sched_entity *prev)
static void
entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr, int queued)
{
- /*
- * Update run-time statistics of the 'current'.
- */
- update_curr(cfs_rq);
-
/*
* Ensure that runnable average is periodically updated.
*/
@@ -10032,6 +10025,11 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued)
struct cfs_rq *cfs_rq;
struct sched_entity *se = &curr->se;

+ /*
+ * Update run-time statistics of the 'current'.
+ */
+ update_curr(&rq->cfs);
+
for_each_sched_entity(se) {
cfs_rq = group_cfs_rq_of_parent(se);
entity_tick(cfs_rq, se, queued);
--
2.20.1