The rt entity can be a task group. We will account execution time for
each task. For consistency, we don't need to account execution time for
task group.

Pass a parameter to update_current_exec_runtime, let the caller decide
whether account execution time.

Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
---
v3: Pass a parameter to update_current_exec_runtime.
v2: Add the missing '#endif'.
v1: https://lore.kernel.org/all/20231023065418.1548239-1-yajun.deng@linux.dev/
---
 kernel/sched/deadline.c  |  2 +-
 kernel/sched/rt.c        |  3 ++-
 kernel/sched/sched.h     | 10 ++++++----
 kernel/sched/stop_task.c |  2 +-
 4 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index b28114478b82..a9f84428c4b5 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -1303,7 +1303,7 @@ static void update_curr_dl(struct rq *rq)
 
 	trace_sched_stat_runtime(curr, delta_exec, 0);
 
-	update_current_exec_runtime(curr, now, delta_exec);
+	update_current_exec_runtime(curr, now, delta_exec, true);
 
 	if (dl_entity_is_special(dl_se))
 		return;
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 6aaf0a3d6081..79cf80d73822 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -1018,7 +1018,8 @@ static void update_curr_rt(struct rq *rq)
 
 	trace_sched_stat_runtime(curr, delta_exec, 0);
 
-	update_current_exec_runtime(curr, now, delta_exec);
+	update_current_exec_runtime(curr, now, delta_exec,
+				    rt_entity_is_task(rt_se));
 
 	if (!rt_bandwidth_enabled())
 		return;
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 2e5a95486a42..6f0169d9b306 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -3262,13 +3262,15 @@ extern void sched_dynamic_update(int mode);
 #endif
 
 static inline void update_current_exec_runtime(struct task_struct *curr,
-						u64 now, u64 delta_exec)
+					       u64 now, u64 delta_exec, bool task)
 {
 	curr->se.sum_exec_runtime += delta_exec;
-	account_group_exec_runtime(curr, delta_exec);
-
 	curr->se.exec_start = now;
-	cgroup_account_cputime(curr, delta_exec);
+
+	if (task) {
+		account_group_exec_runtime(curr, delta_exec);
+		cgroup_account_cputime(curr, delta_exec);
+	}
 }
 
 #ifdef CONFIG_SCHED_MM_CID
diff --git a/kernel/sched/stop_task.c b/kernel/sched/stop_task.c
index 6cf7304e6449..1bec2af7ce8d 100644
--- a/kernel/sched/stop_task.c
+++ b/kernel/sched/stop_task.c
@@ -81,7 +81,7 @@ static void put_prev_task_stop(struct rq *rq, struct task_struct *prev)
 	schedstat_set(curr->stats.exec_max,
 		      max(curr->stats.exec_max, delta_exec));
 
-	update_current_exec_runtime(curr, now, delta_exec);
+	update_current_exec_runtime(curr, now, delta_exec, true);
 }
 
 /*
-- 
2.25.1

On Tue, Oct 31, 2023 at 08:59:26PM +0800, Yajun Deng wrote:
> The rt entity can be a task group. We will account execution time for
> each task. For consistency, we don't need to account execution time for
> task group.
> 
> Pass a parameter to update_current_exec_runtime, let the caller decide
> whether account execution time.
> 

> diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
> index 6aaf0a3d6081..79cf80d73822 100644
> --- a/kernel/sched/rt.c
> +++ b/kernel/sched/rt.c
> @@ -1018,7 +1018,8 @@ static void update_curr_rt(struct rq *rq)
>  
>  	trace_sched_stat_runtime(curr, delta_exec, 0);
>  
> -	update_current_exec_runtime(curr, now, delta_exec);
> +	update_current_exec_runtime(curr, now, delta_exec,
> +				    rt_entity_is_task(rt_se));
>  
>  	if (!rt_bandwidth_enabled())
>  		return;

ok, I think I've managed to confuse myself again.

But at this point rt_se := &rq->curr->rt, which is *always* a task, no?

On 2023/11/6 20:49, Peter Zijlstra wrote:
> On Tue, Oct 31, 2023 at 08:59:26PM +0800, Yajun Deng wrote:
>> The rt entity can be a task group. We will account execution time for
>> each task. For consistency, we don't need to account execution time for
>> task group.
>>
>> Pass a parameter to update_current_exec_runtime, let the caller decide
>> whether account execution time.
>>
>> diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
>> index 6aaf0a3d6081..79cf80d73822 100644
>> --- a/kernel/sched/rt.c
>> +++ b/kernel/sched/rt.c
>> @@ -1018,7 +1018,8 @@ static void update_curr_rt(struct rq *rq)
>>   
>>   	trace_sched_stat_runtime(curr, delta_exec, 0);
>>   
>> -	update_current_exec_runtime(curr, now, delta_exec);
>> +	update_current_exec_runtime(curr, now, delta_exec,
>> +				    rt_entity_is_task(rt_se));
>>   
>>   	if (!rt_bandwidth_enabled())
>>   		return;
> ok, I think I've managed to confuse myself again.
>
> But at this point rt_se := &rq->curr->rt, which is *always* a task, no?


I think so, but it can be safer to use rt_entity_is_task().