* [PATCH -next] sched/deadline: Add compare_task_rq helper
@ 2022-08-26 3:11 Shang XiaoJing
2022-08-26 7:10 ` Daniel Bristot de Oliveira
0 siblings, 1 reply; 3+ messages in thread
From: Shang XiaoJing @ 2022-08-26 3:11 UTC (permalink / raw)
To: mingo, peterz, juri.lelli, vincent.guittot, dietmar.eggemann,
rostedt, bsegall, mgorman, bristot, vschneid, linux-kernel
Cc: shangxiaojing
Wrap repeated code in helper function compare_task_rq, which return true
if there is no deadline task on the rq at all, or task's deadline
earlier than the rq.
Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>
---
kernel/sched/deadline.c | 23 +++++++++++------------
1 file changed, 11 insertions(+), 12 deletions(-)
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index d116d2b9d2f9..4a40a462717c 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -1810,6 +1810,13 @@ static void yield_task_dl(struct rq *rq)
#ifdef CONFIG_SMP
+static inline bool compare_task_rq(struct task_struct *p, struct rq *rq)
+{
+ return (!rq->dl.dl_nr_running ||
+ dl_time_before(p->dl.deadline,
+ rq->dl.earliest_dl.curr));
+}
+
static int find_later_rq(struct task_struct *task);
static int
@@ -1852,9 +1859,7 @@ select_task_rq_dl(struct task_struct *p, int cpu, int flags)
int target = find_later_rq(p);
if (target != -1 &&
- (dl_time_before(p->dl.deadline,
- cpu_rq(target)->dl.earliest_dl.curr) ||
- (cpu_rq(target)->dl.dl_nr_running == 0)))
+ compare_task_rq(p, cpu_rq(target)))
cpu = target;
}
rcu_read_unlock();
@@ -2221,9 +2226,7 @@ static struct rq *find_lock_later_rq(struct task_struct *task, struct rq *rq)
later_rq = cpu_rq(cpu);
- if (later_rq->dl.dl_nr_running &&
- !dl_time_before(task->dl.deadline,
- later_rq->dl.earliest_dl.curr)) {
+ if (!compare_task_rq(task, later_rq)) {
/*
* Target rq has tasks of equal or earlier deadline,
* retrying does not release any lock and is unlikely
@@ -2251,9 +2254,7 @@ static struct rq *find_lock_later_rq(struct task_struct *task, struct rq *rq)
* its earliest one has a later deadline than our
* task, the rq is a good one.
*/
- if (!later_rq->dl.dl_nr_running ||
- dl_time_before(task->dl.deadline,
- later_rq->dl.earliest_dl.curr))
+ if (compare_task_rq(task, later_rq))
break;
/* Otherwise we try again. */
@@ -2424,9 +2425,7 @@ static void pull_dl_task(struct rq *this_rq)
* - it will preempt the last one we pulled (if any).
*/
if (p && dl_time_before(p->dl.deadline, dmin) &&
- (!this_rq->dl.dl_nr_running ||
- dl_time_before(p->dl.deadline,
- this_rq->dl.earliest_dl.curr))) {
+ compare_task_rq(p, this_rq)) {
WARN_ON(p == src_rq->curr);
WARN_ON(!task_on_rq_queued(p));
--
2.17.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH -next] sched/deadline: Add compare_task_rq helper
2022-08-26 3:11 [PATCH -next] sched/deadline: Add compare_task_rq helper Shang XiaoJing
@ 2022-08-26 7:10 ` Daniel Bristot de Oliveira
2022-08-26 7:23 ` shangxiaojing
0 siblings, 1 reply; 3+ messages in thread
From: Daniel Bristot de Oliveira @ 2022-08-26 7:10 UTC (permalink / raw)
To: Shang XiaoJing
Cc: mingo, peterz, vincent.guittot, juri.lelli, dietmar.eggemann,
rostedt, bsegall, mgorman, vschneid, linux-kernel
On 8/26/22 05:11, Shang XiaoJing wrote:
> Wrap repeated code in helper function compare_task_rq, which return true
> if there is no deadline task on the rq at all, or task's deadline
> earlier than the rq.
>
> Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>
> ---
> kernel/sched/deadline.c | 23 +++++++++++------------
> 1 file changed, 11 insertions(+), 12 deletions(-)
>
> diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
> index d116d2b9d2f9..4a40a462717c 100644
> --- a/kernel/sched/deadline.c
> +++ b/kernel/sched/deadline.c
> @@ -1810,6 +1810,13 @@ static void yield_task_dl(struct rq *rq)
>
> #ifdef CONFIG_SMP
I see the value of this helper, but "compare_task_rq" is making things more confuse.
Choose a more descriptive name, like, dl_task_is_earliest_deadline() ?
> +static inline bool compare_task_rq(struct task_struct *p, struct rq *rq)
> +{
> + return (!rq->dl.dl_nr_running ||
> + dl_time_before(p->dl.deadline,
> + rq->dl.earliest_dl.curr));
> +}
> +
-- Daniel
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH -next] sched/deadline: Add compare_task_rq helper
2022-08-26 7:10 ` Daniel Bristot de Oliveira
@ 2022-08-26 7:23 ` shangxiaojing
0 siblings, 0 replies; 3+ messages in thread
From: shangxiaojing @ 2022-08-26 7:23 UTC (permalink / raw)
To: Daniel Bristot de Oliveira
Cc: mingo, peterz, vincent.guittot, juri.lelli, dietmar.eggemann,
rostedt, bsegall, mgorman, vschneid, linux-kernel
On 2022/8/26 15:10, Daniel Bristot de Oliveira wrote:
> On 8/26/22 05:11, Shang XiaoJing wrote:
>> Wrap repeated code in helper function compare_task_rq, which return true
>> if there is no deadline task on the rq at all, or task's deadline
>> earlier than the rq.
>>
>> Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>
>> ---
>> kernel/sched/deadline.c | 23 +++++++++++------------
>> 1 file changed, 11 insertions(+), 12 deletions(-)
>>
>> diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
>> index d116d2b9d2f9..4a40a462717c 100644
>> --- a/kernel/sched/deadline.c
>> +++ b/kernel/sched/deadline.c
>> @@ -1810,6 +1810,13 @@ static void yield_task_dl(struct rq *rq)
>>
>> #ifdef CONFIG_SMP
> I see the value of this helper, but "compare_task_rq" is making things more confuse.
>
> Choose a more descriptive name, like, dl_task_is_earliest_deadline() ?
ok, i'll find a better name, or take your advice directly in v2.
>> +static inline bool compare_task_rq(struct task_struct *p, struct rq *rq)
>> +{
>> + return (!rq->dl.dl_nr_running ||
>> + dl_time_before(p->dl.deadline,
>> + rq->dl.earliest_dl.curr));
>> +}
>> +
> -- Daniel
Thanks :-) ,
Shang XiaoJing
^ permalink raw reply [flat|nested] 3+ messages in thread
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2022-08-26 3:11 [PATCH -next] sched/deadline: Add compare_task_rq helper Shang XiaoJing
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