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* [RESEND PATCH v3 1/2] sched/deadline: Add cpudl_maximum_dl() for clean-up
@ 2017-12-28 23:32 Byungchul Park
  2017-12-28 23:32 ` [RESEND PATCH v3 2/2] sched/deadline: Initialize cp->elements[].cpu to an invalid value Byungchul Park
  0 siblings, 1 reply; 15+ messages in thread
From: Byungchul Park @ 2017-12-28 23:32 UTC (permalink / raw)
  To: peterz, mingo, rostedt
  Cc: tglx, raistlin, linux-kernel, juri.lelli, bristot, kernel-team

Changes from v2
 - Run spellchecker over the text and fix typos
 - Add acked-by Daniel

Changes from v1
 - Enhance commit msg
 - Prevent WARN in cpumask_test_cpu() in cpudl_find() when best_cpu == -1

-----8<-----
>From 7735382d07ae6a61d740ae39ba2ecf169d43b8a2 Mon Sep 17 00:00:00 2001
From: Byungchul Park <byungchul.park@lge.com>
Date: Wed, 22 Mar 2017 14:25:56 +0900
Subject: [RESEND PATCH v3 1/2] sched/deadline: Add cpudl_maximum_dl() for clean-up

Current code uses cpudl_maximum() to get the root node's cpu, while it
directly accesses the root node like 'cp->elements[0].dl' to get the
root node's dl. It would be more readable to add a function for the dl,
as well. Added it.

Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Daniel Bristot de Oliveira <bristot@redhat.com>
---
 kernel/sched/cpudeadline.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c
index 8d9562d..9f02035 100644
--- a/kernel/sched/cpudeadline.c
+++ b/kernel/sched/cpudeadline.c
@@ -108,11 +108,16 @@ static void cpudl_heapify(struct cpudl *cp, int idx)
 		cpudl_heapify_down(cp, idx);
 }
 
-static inline int cpudl_maximum(struct cpudl *cp)
+static inline int cpudl_maximum_cpu(struct cpudl *cp)
 {
 	return cp->elements[0].cpu;
 }
 
+static inline u64 cpudl_maximum_dl(struct cpudl *cp)
+{
+	return cp->elements[0].dl;
+}
+
 /*
  * cpudl_find - find the best (later-dl) CPU in the system
  * @cp: the cpudl max-heap context
@@ -130,11 +135,11 @@ int cpudl_find(struct cpudl *cp, struct task_struct *p,
 	    cpumask_and(later_mask, cp->free_cpus, &p->cpus_allowed)) {
 		return 1;
 	} else {
-		int best_cpu = cpudl_maximum(cp);
+		int best_cpu = cpudl_maximum_cpu(cp);
 		WARN_ON(best_cpu != -1 && !cpu_present(best_cpu));
 
 		if (cpumask_test_cpu(best_cpu, &p->cpus_allowed) &&
-		    dl_time_before(dl_se->deadline, cp->elements[0].dl)) {
+		    dl_time_before(dl_se->deadline, cpudl_maximum_dl(cp))) {
 			if (later_mask)
 				cpumask_set_cpu(best_cpu, later_mask);
 
-- 
1.9.1

^ permalink raw reply related	[flat|nested] 15+ messages in thread

* [RESEND PATCH v3 2/2] sched/deadline: Initialize cp->elements[].cpu to an invalid value
  2017-12-28 23:32 [RESEND PATCH v3 1/2] sched/deadline: Add cpudl_maximum_dl() for clean-up Byungchul Park
@ 2017-12-28 23:32 ` Byungchul Park
  0 siblings, 0 replies; 15+ messages in thread
From: Byungchul Park @ 2017-12-28 23:32 UTC (permalink / raw)
  To: peterz, mingo, rostedt
  Cc: tglx, raistlin, linux-kernel, juri.lelli, bristot, kernel-team

Currently, migrating tasks to cpu0 unconditionally happens when the
heap is empty, since cp->elements[].cpu was initialized to 0(=cpu0).
We have to distinguish between the empty case and cpu0 to avoid the
unnecessary migrations. Therefore, it has to return an invalid value
e.i. -1 in that case.

Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Daniel Bristot de Oliveira <bristot@redhat.com>
---
 kernel/sched/cpudeadline.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c
index 9f02035..bcf903f 100644
--- a/kernel/sched/cpudeadline.c
+++ b/kernel/sched/cpudeadline.c
@@ -138,6 +138,12 @@ int cpudl_find(struct cpudl *cp, struct task_struct *p,
 		int best_cpu = cpudl_maximum_cpu(cp);
 		WARN_ON(best_cpu != -1 && !cpu_present(best_cpu));
 
+		/*
+		 * The heap tree is empty for now, just return.
+		 */
+		if (best_cpu == -1)
+			return 0;
+
 		if (cpumask_test_cpu(best_cpu, &p->cpus_allowed) &&
 		    dl_time_before(dl_se->deadline, cpudl_maximum_dl(cp))) {
 			if (later_mask)
@@ -265,8 +271,10 @@ int cpudl_init(struct cpudl *cp)
 		return -ENOMEM;
 	}
 
-	for_each_possible_cpu(i)
+	for_each_possible_cpu(i) {
+		cp->elements[i].cpu = -1;
 		cp->elements[i].idx = IDX_INVALID;
+	}
 
 	return 0;
 }
-- 
1.9.1

^ permalink raw reply related	[flat|nested] 15+ messages in thread

* Re: [RESEND PATCH v3 1/2] sched/deadline: Add cpudl_maximum_dl() for clean-up
  2018-06-01  6:02         ` Joel Fernandes
@ 2018-06-01  6:30           ` Byungchul Park
  0 siblings, 0 replies; 15+ messages in thread
From: Byungchul Park @ 2018-06-01  6:30 UTC (permalink / raw)
  To: Joel Fernandes
  Cc: Peter Zijlstra, mingo, rostedt, tglx, raistlin, linux-kernel,
	juri.lelli, bristot, kernel-team



On 2018-06-01 15:02, Joel Fernandes wrote:
> On Fri, Jun 01, 2018 at 12:07:48PM +0900, Byungchul Park wrote:
>>
>>
>> On 2018-05-25 14:13, Byungchul Park wrote:
>>>
>>>
>>> On 2018-05-09 15:33, Byungchul Park wrote:
>>>> On Thu, Jan 11, 2018 at 10:07:16AM +0100, Peter Zijlstra wrote:
>>>>>
>>>>>
>>>>> Sorry for the huge delay on this, but I'll have to postpone further.
>>>>> Still busy with meltdown/spectre stuff.
>>>>
>>>> Please consider this. Even though it's not a big bug, anyway leading
>>>> mis-behavior in certain situaions.
>>>
>>> Could you see this patches, it's been too long since the start tho?
>>
>> Please, any opinion.
> 
> Just my opinion: this patch [1] is just a cosmetic change. I would argue that
> there's no readability improvement by wrapping up elements[0].dl. Infact I
> even feel that the elements[0].cpu should directly be accessed since both
> .cpu and .dl for the 0th element are directly accessed only from one place
> (cpudl_find) and only one time, and explicitly accessing index 0 makes it
> more clear that this is the root of the max-heap.
> 
> IOW I don't see any benefit in hiding it behind a wrapper which hides the
> fact that we're accessing the root of the max heap, but I don't terribly hate
> this patch and I'm Ok if maintainers and other reviewers think its worth it.

Hi Joel,

Talking about the *1st patch*, no matter whether denied or not, even
though I think it looks weird to abstract only p->elements[0].cpu with
a function, but not cp->elements[0].dl.

> thanks,
> 
>   - Joel
> 
> [1] https://patchwork.kernel.org/patch/10149099/
> 
> 

-- 
Thanks,
Byungchul

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [RESEND PATCH v3 1/2] sched/deadline: Add cpudl_maximum_dl() for clean-up
  2018-06-01  3:07       ` Byungchul Park
@ 2018-06-01  6:02         ` Joel Fernandes
  2018-06-01  6:30           ` Byungchul Park
  0 siblings, 1 reply; 15+ messages in thread
From: Joel Fernandes @ 2018-06-01  6:02 UTC (permalink / raw)
  To: Byungchul Park
  Cc: Peter Zijlstra, mingo, rostedt, tglx, raistlin, linux-kernel,
	juri.lelli, bristot, kernel-team

On Fri, Jun 01, 2018 at 12:07:48PM +0900, Byungchul Park wrote:
> 
> 
> On 2018-05-25 14:13, Byungchul Park wrote:
> > 
> > 
> > On 2018-05-09 15:33, Byungchul Park wrote:
> > > On Thu, Jan 11, 2018 at 10:07:16AM +0100, Peter Zijlstra wrote:
> > > > 
> > > > 
> > > > Sorry for the huge delay on this, but I'll have to postpone further.
> > > > Still busy with meltdown/spectre stuff.
> > > 
> > > Please consider this. Even though it's not a big bug, anyway leading
> > > mis-behavior in certain situaions.
> > 
> > Could you see this patches, it's been too long since the start tho?
> 
> Please, any opinion.

Just my opinion: this patch [1] is just a cosmetic change. I would argue that
there's no readability improvement by wrapping up elements[0].dl. Infact I
even feel that the elements[0].cpu should directly be accessed since both
.cpu and .dl for the 0th element are directly accessed only from one place
(cpudl_find) and only one time, and explicitly accessing index 0 makes it
more clear that this is the root of the max-heap.

IOW I don't see any benefit in hiding it behind a wrapper which hides the
fact that we're accessing the root of the max heap, but I don't terribly hate
this patch and I'm Ok if maintainers and other reviewers think its worth it.

thanks,

 - Joel

[1] https://patchwork.kernel.org/patch/10149099/

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [RESEND PATCH v3 1/2] sched/deadline: Add cpudl_maximum_dl() for clean-up
  2018-05-25  5:13     ` Byungchul Park
@ 2018-06-01  3:07       ` Byungchul Park
  2018-06-01  6:02         ` Joel Fernandes
  0 siblings, 1 reply; 15+ messages in thread
From: Byungchul Park @ 2018-06-01  3:07 UTC (permalink / raw)
  To: Peter Zijlstra
  Cc: mingo, rostedt, tglx, raistlin, linux-kernel, juri.lelli,
	bristot, kernel-team



On 2018-05-25 14:13, Byungchul Park wrote:
> 
> 
> On 2018-05-09 15:33, Byungchul Park wrote:
>> On Thu, Jan 11, 2018 at 10:07:16AM +0100, Peter Zijlstra wrote:
>>>
>>>
>>> Sorry for the huge delay on this, but I'll have to postpone further.
>>> Still busy with meltdown/spectre stuff.
>>
>> Please consider this. Even though it's not a big bug, anyway leading
>> mis-behavior in certain situaions.
> 
> Could you see this patches, it's been too long since the start tho?

Please, any opinion.

-- 
Thanks,
Byungchul

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [RESEND PATCH v3 1/2] sched/deadline: Add cpudl_maximum_dl() for clean-up
  2018-05-09  6:33   ` Byungchul Park
@ 2018-05-25  5:13     ` Byungchul Park
  2018-06-01  3:07       ` Byungchul Park
  0 siblings, 1 reply; 15+ messages in thread
From: Byungchul Park @ 2018-05-25  5:13 UTC (permalink / raw)
  To: Peter Zijlstra
  Cc: mingo, rostedt, tglx, raistlin, linux-kernel, juri.lelli,
	bristot, kernel-team



On 2018-05-09 15:33, Byungchul Park wrote:
> On Thu, Jan 11, 2018 at 10:07:16AM +0100, Peter Zijlstra wrote:
>>
>>
>> Sorry for the huge delay on this, but I'll have to postpone further.
>> Still busy with meltdown/spectre stuff.
> 
> Please consider this. Even though it's not a big bug, anyway leading
> mis-behavior in certain situaions.

Could you see this patches, it's been too long since the start tho?

-- 
Thanks,
Byungchul

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [RESEND PATCH v3 1/2] sched/deadline: Add cpudl_maximum_dl() for clean-up
  2018-01-11  9:07 ` Peter Zijlstra
                     ` (2 preceding siblings ...)
  2018-03-13  5:52   ` Byungchul Park
@ 2018-05-09  6:33   ` Byungchul Park
  2018-05-25  5:13     ` Byungchul Park
  3 siblings, 1 reply; 15+ messages in thread
From: Byungchul Park @ 2018-05-09  6:33 UTC (permalink / raw)
  To: Peter Zijlstra
  Cc: mingo, rostedt, tglx, raistlin, linux-kernel, juri.lelli,
	bristot, kernel-team

On Thu, Jan 11, 2018 at 10:07:16AM +0100, Peter Zijlstra wrote:
> 
> 
> Sorry for the huge delay on this, but I'll have to postpone further.
> Still busy with meltdown/spectre stuff.

Please consider this. Even though it's not a big bug, anyway leading
mis-behavior in certain situaions.

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [RESEND PATCH v3 1/2] sched/deadline: Add cpudl_maximum_dl() for clean-up
  2018-03-13  5:52   ` Byungchul Park
@ 2018-04-23  7:01     ` Byungchul Park
  0 siblings, 0 replies; 15+ messages in thread
From: Byungchul Park @ 2018-04-23  7:01 UTC (permalink / raw)
  To: Peter Zijlstra
  Cc: mingo, rostedt, tglx, raistlin, linux-kernel, juri.lelli,
	bristot, kernel-team

On 3/13/2018 2:52 PM, Byungchul Park wrote:
> On 1/11/2018 6:07 PM, Peter Zijlstra wrote:
>>
>>
>> Sorry for the huge delay on this, but I'll have to postpone further.
>> Still busy with meltdown/spectre stuff.
> 
> Could you review the patch?

Hello,

Could you see the patch now?

-- 
Thanks,
Byungchul

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [RESEND PATCH v3 1/2] sched/deadline: Add cpudl_maximum_dl() for clean-up
  2018-01-11  9:07 ` Peter Zijlstra
  2018-02-09  0:37   ` Byungchul Park
  2018-02-26  7:51   ` Byungchul Park
@ 2018-03-13  5:52   ` Byungchul Park
  2018-04-23  7:01     ` Byungchul Park
  2018-05-09  6:33   ` Byungchul Park
  3 siblings, 1 reply; 15+ messages in thread
From: Byungchul Park @ 2018-03-13  5:52 UTC (permalink / raw)
  To: Peter Zijlstra
  Cc: mingo, rostedt, tglx, raistlin, linux-kernel, juri.lelli,
	bristot, kernel-team

On 1/11/2018 6:07 PM, Peter Zijlstra wrote:
> 
> 
> Sorry for the huge delay on this, but I'll have to postpone further.
> Still busy with meltdown/spectre stuff.

Could you review the patch?

-- 
Thanks,
Byungchul

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [RESEND PATCH v3 1/2] sched/deadline: Add cpudl_maximum_dl() for clean-up
  2018-01-11  9:07 ` Peter Zijlstra
  2018-02-09  0:37   ` Byungchul Park
@ 2018-02-26  7:51   ` Byungchul Park
  2018-03-13  5:52   ` Byungchul Park
  2018-05-09  6:33   ` Byungchul Park
  3 siblings, 0 replies; 15+ messages in thread
From: Byungchul Park @ 2018-02-26  7:51 UTC (permalink / raw)
  To: Peter Zijlstra
  Cc: mingo, rostedt, tglx, raistlin, linux-kernel, juri.lelli,
	bristot, kernel-team

On 1/11/2018 6:07 PM, Peter Zijlstra wrote:
> 
> 
> Sorry for the huge delay on this, but I'll have to postpone further.
> Still busy with meltdown/spectre stuff.

Do you have time to see the patch, now that it seems to be managed
to solve those security issues?

-- 
Thanks,
Byungchul

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [RESEND PATCH v3 1/2] sched/deadline: Add cpudl_maximum_dl() for clean-up
  2018-01-11  9:07 ` Peter Zijlstra
@ 2018-02-09  0:37   ` Byungchul Park
  2018-02-26  7:51   ` Byungchul Park
                     ` (2 subsequent siblings)
  3 siblings, 0 replies; 15+ messages in thread
From: Byungchul Park @ 2018-02-09  0:37 UTC (permalink / raw)
  To: Peter Zijlstra
  Cc: mingo, rostedt, tglx, raistlin, linux-kernel, juri.lelli,
	bristot, kernel-team

On 1/11/2018 6:07 PM, Peter Zijlstra wrote:
> 
> 
> Sorry for the huge delay on this, but I'll have to postpone further.
> Still busy with meltdown/spectre stuff.

Do you have time to see these patches and another set, now?

-- 
Thanks,
Byungchul

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [RESEND PATCH v3 1/2] sched/deadline: Add cpudl_maximum_dl() for clean-up
  2018-01-08  6:14 [RESEND PATCH v3 1/2] sched/deadline: Add cpudl_maximum_dl() for clean-up Byungchul Park
@ 2018-01-11  9:07 ` Peter Zijlstra
  2018-02-09  0:37   ` Byungchul Park
                     ` (3 more replies)
  0 siblings, 4 replies; 15+ messages in thread
From: Peter Zijlstra @ 2018-01-11  9:07 UTC (permalink / raw)
  To: Byungchul Park
  Cc: mingo, rostedt, tglx, raistlin, linux-kernel, juri.lelli,
	bristot, kernel-team



Sorry for the huge delay on this, but I'll have to postpone further.
Still busy with meltdown/spectre stuff.

^ permalink raw reply	[flat|nested] 15+ messages in thread

* [RESEND PATCH v3 1/2] sched/deadline: Add cpudl_maximum_dl() for clean-up
@ 2018-01-08  6:14 Byungchul Park
  2018-01-11  9:07 ` Peter Zijlstra
  0 siblings, 1 reply; 15+ messages in thread
From: Byungchul Park @ 2018-01-08  6:14 UTC (permalink / raw)
  To: peterz, mingo, rostedt
  Cc: tglx, raistlin, linux-kernel, juri.lelli, bristot, kernel-team

Changes from v2
 - Run spellchecker over the text and fix typos
 - Add acked-by Daniel

Changes from v1
 - Enhance commit msg
 - Prevent WARN in cpumask_test_cpu() in cpudl_find() when best_cpu == -1

-----8<-----
>From 7735382d07ae6a61d740ae39ba2ecf169d43b8a2 Mon Sep 17 00:00:00 2001
From: Byungchul Park <byungchul.park@lge.com>
Date: Wed, 22 Mar 2017 14:25:56 +0900
Subject: [RESEND PATCH v3 1/2] sched/deadline: Add cpudl_maximum_dl() for clean-up

Current code uses cpudl_maximum() to get the root node's cpu, while it
directly accesses the root node like 'cp->elements[0].dl' to get the
root node's dl. It would be more readable to add a function for the dl,
as well. Added it.

Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Daniel Bristot de Oliveira <bristot@redhat.com>
---
 kernel/sched/cpudeadline.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c
index 8d9562d..9f02035 100644
--- a/kernel/sched/cpudeadline.c
+++ b/kernel/sched/cpudeadline.c
@@ -108,11 +108,16 @@ static void cpudl_heapify(struct cpudl *cp, int idx)
 		cpudl_heapify_down(cp, idx);
 }
 
-static inline int cpudl_maximum(struct cpudl *cp)
+static inline int cpudl_maximum_cpu(struct cpudl *cp)
 {
 	return cp->elements[0].cpu;
 }
 
+static inline u64 cpudl_maximum_dl(struct cpudl *cp)
+{
+	return cp->elements[0].dl;
+}
+
 /*
  * cpudl_find - find the best (later-dl) CPU in the system
  * @cp: the cpudl max-heap context
@@ -130,11 +135,11 @@ int cpudl_find(struct cpudl *cp, struct task_struct *p,
 	    cpumask_and(later_mask, cp->free_cpus, &p->cpus_allowed)) {
 		return 1;
 	} else {
-		int best_cpu = cpudl_maximum(cp);
+		int best_cpu = cpudl_maximum_cpu(cp);
 		WARN_ON(best_cpu != -1 && !cpu_present(best_cpu));
 
 		if (cpumask_test_cpu(best_cpu, &p->cpus_allowed) &&
-		    dl_time_before(dl_se->deadline, cp->elements[0].dl)) {
+		    dl_time_before(dl_se->deadline, cpudl_maximum_dl(cp))) {
 			if (later_mask)
 				cpumask_set_cpu(best_cpu, later_mask);
 
-- 
1.9.1

^ permalink raw reply related	[flat|nested] 15+ messages in thread

* Re: [RESEND PATCH v3 1/2] sched/deadline: Add cpudl_maximum_dl() for clean-up
  2017-12-19  1:19 Byungchul Park
@ 2017-12-22  6:53 ` Byungchul Park
  0 siblings, 0 replies; 15+ messages in thread
From: Byungchul Park @ 2017-12-22  6:53 UTC (permalink / raw)
  To: peterz, mingo, rostedt
  Cc: tglx, raistlin, linux-kernel, juri.lelli, bristot, kernel-team

On Tue, Dec 19, 2017 at 10:19:23AM +0900, Byungchul Park wrote:
> Changes from v2
>  - Run spellchecker over the text and fix typos
>  - Add acked-by Daniel
> 
> Changes from v1
>  - Enhance commit msg
>  - Prevent WARN in cpumask_test_cpu() in cpudl_find() when best_cpu == -1

Hello, shall I stop sending this? Let me know if so.

> -----8<-----
> >From 7735382d07ae6a61d740ae39ba2ecf169d43b8a2 Mon Sep 17 00:00:00 2001
> From: Byungchul Park <byungchul.park@lge.com>
> Date: Wed, 22 Mar 2017 14:25:56 +0900
> Subject: [RESEND PATCH v3 1/2] sched/deadline: Add cpudl_maximum_dl() for clean-up
> 
> Current code uses cpudl_maximum() to get the root node's cpu, while it
> directly accesses the root node like 'cp->elements[0].dl' to get the
> root node's dl. It would be more readable to add a function for the dl,
> as well. Added it.
> 
> Signed-off-by: Byungchul Park <byungchul.park@lge.com>
> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
> Acked-by: Daniel Bristot de Oliveira <bristot@redhat.com>
> ---
>  kernel/sched/cpudeadline.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c
> index 8d9562d..9f02035 100644
> --- a/kernel/sched/cpudeadline.c
> +++ b/kernel/sched/cpudeadline.c
> @@ -108,11 +108,16 @@ static void cpudl_heapify(struct cpudl *cp, int idx)
>  		cpudl_heapify_down(cp, idx);
>  }
>  
> -static inline int cpudl_maximum(struct cpudl *cp)
> +static inline int cpudl_maximum_cpu(struct cpudl *cp)
>  {
>  	return cp->elements[0].cpu;
>  }
>  
> +static inline u64 cpudl_maximum_dl(struct cpudl *cp)
> +{
> +	return cp->elements[0].dl;
> +}
> +
>  /*
>   * cpudl_find - find the best (later-dl) CPU in the system
>   * @cp: the cpudl max-heap context
> @@ -130,11 +135,11 @@ int cpudl_find(struct cpudl *cp, struct task_struct *p,
>  	    cpumask_and(later_mask, cp->free_cpus, &p->cpus_allowed)) {
>  		return 1;
>  	} else {
> -		int best_cpu = cpudl_maximum(cp);
> +		int best_cpu = cpudl_maximum_cpu(cp);
>  		WARN_ON(best_cpu != -1 && !cpu_present(best_cpu));
>  
>  		if (cpumask_test_cpu(best_cpu, &p->cpus_allowed) &&
> -		    dl_time_before(dl_se->deadline, cp->elements[0].dl)) {
> +		    dl_time_before(dl_se->deadline, cpudl_maximum_dl(cp))) {
>  			if (later_mask)
>  				cpumask_set_cpu(best_cpu, later_mask);
>  
> -- 
> 1.9.1

^ permalink raw reply	[flat|nested] 15+ messages in thread

* [RESEND PATCH v3 1/2] sched/deadline: Add cpudl_maximum_dl() for clean-up
@ 2017-12-19  1:19 Byungchul Park
  2017-12-22  6:53 ` Byungchul Park
  0 siblings, 1 reply; 15+ messages in thread
From: Byungchul Park @ 2017-12-19  1:19 UTC (permalink / raw)
  To: peterz, mingo, rostedt
  Cc: tglx, raistlin, linux-kernel, juri.lelli, bristot, kernel-team

Changes from v2
 - Run spellchecker over the text and fix typos
 - Add acked-by Daniel

Changes from v1
 - Enhance commit msg
 - Prevent WARN in cpumask_test_cpu() in cpudl_find() when best_cpu == -1

-----8<-----
>From 7735382d07ae6a61d740ae39ba2ecf169d43b8a2 Mon Sep 17 00:00:00 2001
From: Byungchul Park <byungchul.park@lge.com>
Date: Wed, 22 Mar 2017 14:25:56 +0900
Subject: [RESEND PATCH v3 1/2] sched/deadline: Add cpudl_maximum_dl() for clean-up

Current code uses cpudl_maximum() to get the root node's cpu, while it
directly accesses the root node like 'cp->elements[0].dl' to get the
root node's dl. It would be more readable to add a function for the dl,
as well. Added it.

Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Daniel Bristot de Oliveira <bristot@redhat.com>
---
 kernel/sched/cpudeadline.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c
index 8d9562d..9f02035 100644
--- a/kernel/sched/cpudeadline.c
+++ b/kernel/sched/cpudeadline.c
@@ -108,11 +108,16 @@ static void cpudl_heapify(struct cpudl *cp, int idx)
 		cpudl_heapify_down(cp, idx);
 }
 
-static inline int cpudl_maximum(struct cpudl *cp)
+static inline int cpudl_maximum_cpu(struct cpudl *cp)
 {
 	return cp->elements[0].cpu;
 }
 
+static inline u64 cpudl_maximum_dl(struct cpudl *cp)
+{
+	return cp->elements[0].dl;
+}
+
 /*
  * cpudl_find - find the best (later-dl) CPU in the system
  * @cp: the cpudl max-heap context
@@ -130,11 +135,11 @@ int cpudl_find(struct cpudl *cp, struct task_struct *p,
 	    cpumask_and(later_mask, cp->free_cpus, &p->cpus_allowed)) {
 		return 1;
 	} else {
-		int best_cpu = cpudl_maximum(cp);
+		int best_cpu = cpudl_maximum_cpu(cp);
 		WARN_ON(best_cpu != -1 && !cpu_present(best_cpu));
 
 		if (cpumask_test_cpu(best_cpu, &p->cpus_allowed) &&
-		    dl_time_before(dl_se->deadline, cp->elements[0].dl)) {
+		    dl_time_before(dl_se->deadline, cpudl_maximum_dl(cp))) {
 			if (later_mask)
 				cpumask_set_cpu(best_cpu, later_mask);
 
-- 
1.9.1

^ permalink raw reply related	[flat|nested] 15+ messages in thread

end of thread, other threads:[~2018-06-01  6:30 UTC | newest]

Thread overview: 15+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-12-28 23:32 [RESEND PATCH v3 1/2] sched/deadline: Add cpudl_maximum_dl() for clean-up Byungchul Park
2017-12-28 23:32 ` [RESEND PATCH v3 2/2] sched/deadline: Initialize cp->elements[].cpu to an invalid value Byungchul Park
  -- strict thread matches above, loose matches on Subject: below --
2018-01-08  6:14 [RESEND PATCH v3 1/2] sched/deadline: Add cpudl_maximum_dl() for clean-up Byungchul Park
2018-01-11  9:07 ` Peter Zijlstra
2018-02-09  0:37   ` Byungchul Park
2018-02-26  7:51   ` Byungchul Park
2018-03-13  5:52   ` Byungchul Park
2018-04-23  7:01     ` Byungchul Park
2018-05-09  6:33   ` Byungchul Park
2018-05-25  5:13     ` Byungchul Park
2018-06-01  3:07       ` Byungchul Park
2018-06-01  6:02         ` Joel Fernandes
2018-06-01  6:30           ` Byungchul Park
2017-12-19  1:19 Byungchul Park
2017-12-22  6:53 ` Byungchul Park

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