lkml.org 
[lkml]   [2017]   [Feb]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] sched: deadline: Fix confusing comments about selection of top pi-waiter
Date
This comment in the code is incomplete, and I believe it begs a definition of
dl_boosted to make sense of the condition that follows. Rewrite the comment and
also rearrange the condition that follows to reflect the first condition "we
have a top pi-waiter which is a SCHED_DEADLINE task" in that order. Also fix a
typo that follows.

Cc: Juri Lelli <Juri.Lelli@arm.com>
Signed-off-by: Joel Fernandes <joelaf@google.com>
---
kernel/sched/deadline.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 70ef2b1901e4..4b86abcef135 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -928,17 +928,19 @@ static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags)
struct sched_dl_entity *pi_se = &p->dl;

/*
- * Use the scheduling parameters of the top pi-waiter
- * task if we have one and its (absolute) deadline is
- * smaller than our one... OTW we keep our runtime and
- * deadline.
+ * Use the scheduling parameters of the top pi-waiter task if:
+ * - we have a top pi-waiter which is a SCHED_DEADLINE task AND
+ * - our dl_boosted is set (i.e. the pi-waiter's (absolute) deadline is
+ * smaller than our deadline OR we are a !SCHED_DEADLINE task getting
+ * boosted due to a SCHED_DEADLINE pi-waiter).
+ * Otherwise we keep our runtime and deadline.
*/
- if (pi_task && p->dl.dl_boosted && dl_prio(pi_task->normal_prio)) {
+ if (pi_task && dl_prio(pi_task->normal_prio) && p->dl.dl_boosted) {
pi_se = &pi_task->dl;
} else if (!dl_prio(p->normal_prio)) {
/*
* Special case in which we have a !SCHED_DEADLINE task
- * that is going to be deboosted, but exceedes its
+ * that is going to be deboosted, but exceeds its
* runtime while doing so. No point in replenishing
* it, as it's going to return back to its original
* scheduling class after this.
--
2.11.0.483.g087da7b7c-goog
\
 
 \ /
  Last update: 2017-02-23 05:11    [W:0.312 / U:0.032 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site