* [RESEND PATCH v3 1/2] sched/deadline: Add cpudl_maximum_dl() for clean-up
@ 2017-12-19 1:19 Byungchul Park
2017-12-19 1:19 ` [RESEND PATCH v3 2/2] sched/deadline: Initialize cp->elements[].cpu to an invalid value Byungchul Park
2017-12-22 6:53 ` [RESEND PATCH v3 1/2] sched/deadline: Add cpudl_maximum_dl() for clean-up Byungchul Park
0 siblings, 2 replies; 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
* [RESEND PATCH v3 2/2] sched/deadline: Initialize cp->elements[].cpu to an invalid value
2017-12-19 1:19 [RESEND PATCH v3 1/2] sched/deadline: Add cpudl_maximum_dl() for clean-up Byungchul Park
@ 2017-12-19 1:19 ` Byungchul Park
2017-12-22 6:53 ` [RESEND PATCH v3 1/2] sched/deadline: Add cpudl_maximum_dl() for clean-up Byungchul Park
1 sibling, 0 replies; 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
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
2017-12-19 1:19 [RESEND PATCH v3 1/2] sched/deadline: Add cpudl_maximum_dl() for clean-up Byungchul Park
2017-12-19 1:19 ` [RESEND PATCH v3 2/2] sched/deadline: Initialize cp->elements[].cpu to an invalid value Byungchul Park
@ 2017-12-22 6:53 ` Byungchul Park
1 sibling, 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
@ 2017-12-28 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
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 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
2018-01-08 6:14 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
* 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
2018-01-11 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
@ 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
2018-03-13 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
` (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
2018-05-09 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
2018-05-25 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
2018-06-01 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
2018-06-01 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
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 --
2017-12-19 1:19 [RESEND PATCH v3 1/2] sched/deadline: Add cpudl_maximum_dl() for clean-up Byungchul Park
2017-12-19 1:19 ` [RESEND PATCH v3 2/2] sched/deadline: Initialize cp->elements[].cpu to an invalid value Byungchul Park
2017-12-22 6:53 ` [RESEND PATCH v3 1/2] sched/deadline: Add cpudl_maximum_dl() for clean-up Byungchul Park
2017-12-28 23:32 Byungchul Park
2018-01-08 6:14 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
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