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* [PATCH] rcu: Report a quiescent state of TASKS_RCU on a tick from user
@ 2018-05-15  0:33 Byungchul Park
  2018-05-15  4:11 ` Paul E. McKenney
  0 siblings, 1 reply; 3+ messages in thread
From: Byungchul Park @ 2018-05-15  0:33 UTC (permalink / raw)
  To: jiangshanlai, paulmck, josh, rostedt, mathieu.desnoyers
  Cc: linux-kernel, kernel-team, joel

Hello Paul,

You removed the reporing while simplifying the commit 508880df6 :)
Fold this patch onto the commit or add, whatever you want.

Thanks,
Byungchul

----->8-----
>From 18a2d8da3baf79d0edd5ccf94abe6f989da5b1c1 Mon Sep 17 00:00:00 2001
From: Byungchul Park <byungchul.park@lge.com>
Date: Tue, 15 May 2018 09:21:43 +0900
Subject: [PATCH] rcu: Report a quiescent state of TASKS_RCU on a tick from
 user

The reporting was removed while simplifying the commit 508880df6 (rcu:
Improve rcu_note_voluntary_context_switch() reporting). Add it back.

Signed-off-by: Byungchul Park <byungchul.park@lge.com>
---
 kernel/rcu/tiny.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c
index befc932..3345596 100644
--- a/kernel/rcu/tiny.c
+++ b/kernel/rcu/tiny.c
@@ -120,8 +120,10 @@ void rcu_bh_qs(void)
  */
 void rcu_check_callbacks(int user)
 {
-	if (user)
+	if (user) {
 		rcu_sched_qs();
+		rcu_tasks_qs();
+	}
 	if (user || !in_softirq())
 		rcu_bh_qs();
 }
-- 
1.9.1

^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] rcu: Report a quiescent state of TASKS_RCU on a tick from user
  2018-05-15  0:33 [PATCH] rcu: Report a quiescent state of TASKS_RCU on a tick from user Byungchul Park
@ 2018-05-15  4:11 ` Paul E. McKenney
  2018-05-15  4:19   ` Byungchul Park
  0 siblings, 1 reply; 3+ messages in thread
From: Paul E. McKenney @ 2018-05-15  4:11 UTC (permalink / raw)
  To: Byungchul Park
  Cc: jiangshanlai, josh, rostedt, mathieu.desnoyers, linux-kernel,
	kernel-team, joel

On Tue, May 15, 2018 at 09:33:46AM +0900, Byungchul Park wrote:
> Hello Paul,
> 
> You removed the reporing while simplifying the commit 508880df6 :)
> Fold this patch onto the commit or add, whatever you want.

First, thank you for checking!

But second, the removal was intentional.  Tiny RCU only exists in
PREEMPT=n kernels, and in such kernels there can be no RCU-tasks.
This is the reason for this line in the new commit log:

[ paulmck: Simplify rcutiny portion given no RCU-tasks for !PREEMPT. ]

							Thanx, Paul

> Thanks,
> Byungchul
> 
> ----->8-----
> >From 18a2d8da3baf79d0edd5ccf94abe6f989da5b1c1 Mon Sep 17 00:00:00 2001
> From: Byungchul Park <byungchul.park@lge.com>
> Date: Tue, 15 May 2018 09:21:43 +0900
> Subject: [PATCH] rcu: Report a quiescent state of TASKS_RCU on a tick from
>  user
> 
> The reporting was removed while simplifying the commit 508880df6 (rcu:
> Improve rcu_note_voluntary_context_switch() reporting). Add it back.
> 
> Signed-off-by: Byungchul Park <byungchul.park@lge.com>
> ---
>  kernel/rcu/tiny.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c
> index befc932..3345596 100644
> --- a/kernel/rcu/tiny.c
> +++ b/kernel/rcu/tiny.c
> @@ -120,8 +120,10 @@ void rcu_bh_qs(void)
>   */
>  void rcu_check_callbacks(int user)
>  {
> -	if (user)
> +	if (user) {
>  		rcu_sched_qs();
> +		rcu_tasks_qs();
> +	}
>  	if (user || !in_softirq())
>  		rcu_bh_qs();
>  }
> -- 
> 1.9.1
> 

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] rcu: Report a quiescent state of TASKS_RCU on a tick from user
  2018-05-15  4:11 ` Paul E. McKenney
@ 2018-05-15  4:19   ` Byungchul Park
  0 siblings, 0 replies; 3+ messages in thread
From: Byungchul Park @ 2018-05-15  4:19 UTC (permalink / raw)
  To: paulmck
  Cc: jiangshanlai, josh, rostedt, mathieu.desnoyers, linux-kernel,
	kernel-team, joel



On 2018-05-15 13:11, Paul E. McKenney wrote:
> On Tue, May 15, 2018 at 09:33:46AM +0900, Byungchul Park wrote:
>> Hello Paul,
>>
>> You removed the reporing while simplifying the commit 508880df6 :)
>> Fold this patch onto the commit or add, whatever you want.
> 
> First, thank you for checking!
> 
> But second, the removal was intentional.  Tiny RCU only exists in
> PREEMPT=n kernels, and in such kernels there can be no RCU-tasks.
> This is the reason for this line in the new commit log:

I see. Thank you.

> [ paulmck: Simplify rcutiny portion given no RCU-tasks for !PREEMPT. ]
> 
> 							Thanx, Paul
> 
>> Thanks,
>> Byungchul
>>
>> ----->8-----
>> >From 18a2d8da3baf79d0edd5ccf94abe6f989da5b1c1 Mon Sep 17 00:00:00 2001
>> From: Byungchul Park <byungchul.park@lge.com>
>> Date: Tue, 15 May 2018 09:21:43 +0900
>> Subject: [PATCH] rcu: Report a quiescent state of TASKS_RCU on a tick from
>>   user
>>
>> The reporting was removed while simplifying the commit 508880df6 (rcu:
>> Improve rcu_note_voluntary_context_switch() reporting). Add it back.
>>
>> Signed-off-by: Byungchul Park <byungchul.park@lge.com>
>> ---
>>   kernel/rcu/tiny.c | 4 +++-
>>   1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c
>> index befc932..3345596 100644
>> --- a/kernel/rcu/tiny.c
>> +++ b/kernel/rcu/tiny.c
>> @@ -120,8 +120,10 @@ void rcu_bh_qs(void)
>>    */
>>   void rcu_check_callbacks(int user)
>>   {
>> -	if (user)
>> +	if (user) {
>>   		rcu_sched_qs();
>> +		rcu_tasks_qs();
>> +	}
>>   	if (user || !in_softirq())
>>   		rcu_bh_qs();
>>   }
>> -- 
>> 1.9.1
>>
> 
> 

-- 
Thanks,
Byungchul

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2018-05-15  4:19 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2018-05-15  0:33 [PATCH] rcu: Report a quiescent state of TASKS_RCU on a tick from user Byungchul Park
2018-05-15  4:11 ` Paul E. McKenney
2018-05-15  4:19   ` Byungchul Park

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