2024-01-30 13:14:48

by alexs

Subject: [PATCH v2 3/6] sched/fair: cleanup sched_use_asym_prio

From: Alex Shi <[email protected]>

And simplify the one line code. No function change.

Signed-off-by: Alex Shi <[email protected]>
To: Ricardo Neri <[email protected]>
To: Valentin Schneider <[email protected]>
To: Vincent Guittot <[email protected]>
To: Peter Zijlstra <[email protected]>
To: Ingo Molnar <[email protected]>
---
kernel/sched/fair.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 8d70417f5125..ebd659af2d78 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -9741,10 +9741,8 @@ group_type group_classify(unsigned int imbalance_pct,
*/
static bool sched_use_asym_prio(struct sched_domain *sd, int cpu)
{
- if (!sched_smt_active())
- return true;
-
- return sd->flags & SD_SHARE_CPUCAPACITY || is_core_idle(cpu);
+ return (!sched_smt_active()) ||
+ (sd->flags & SD_SHARE_CPUCAPACITY) || is_core_idle(cpu);
}

/**
--
2.43.0

2024-02-01 01:14:49

by Ricardo Neri

Subject: Re: [PATCH v2 3/6] sched/fair: cleanup sched_use_asym_prio

On Tue, Jan 30, 2024 at 09:17:05PM +0800, [email protected] wrote:
> From: Alex Shi <[email protected]>
>
> And simplify the one line code. No function change.
>
> Signed-off-by: Alex Shi <[email protected]>
> To: Ricardo Neri <[email protected]>
> To: Valentin Schneider <[email protected]>
> To: Vincent Guittot <[email protected]>
> To: Peter Zijlstra <[email protected]>
> To: Ingo Molnar <[email protected]>
> ---
> kernel/sched/fair.c | 6 ++----
> 1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 8d70417f5125..ebd659af2d78 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -9741,10 +9741,8 @@ group_type group_classify(unsigned int imbalance_pct,
> */
> static bool sched_use_asym_prio(struct sched_domain *sd, int cpu)
> {
> - if (!sched_smt_active())
> - return true;
> -
> - return sd->flags & SD_SHARE_CPUCAPACITY || is_core_idle(cpu);
> + return (!sched_smt_active()) ||
> + (sd->flags & SD_SHARE_CPUCAPACITY) || is_core_idle(cpu);

I think that compressing the two conditions into one hurts readability.
As implemented, it is clear that no further checks are required if there
is no SMT.

Also, please see my comment in patch 6/6.

2024-02-01 08:42:33

by Alex Shi

Subject: Re: [PATCH v2 3/6] sched/fair: cleanup sched_use_asym_prio

On 2/1/24 9:13 AM, Ricardo Neri wrote:
> On Tue, Jan 30, 2024 at 09:17:05PM +0800, [email protected] wrote:
>> From: Alex Shi <[email protected]>
>>
>> And simplify the one line code. No function change.
>>
>> Signed-off-by: Alex Shi <[email protected]>
>> To: Ricardo Neri <[email protected]>
>> To: Valentin Schneider <[email protected]>
>> To: Vincent Guittot <[email protected]>
>> To: Peter Zijlstra <[email protected]>
>> To: Ingo Molnar <[email protected]>
>> ---
>> kernel/sched/fair.c | 6 ++----
>> 1 file changed, 2 insertions(+), 4 deletions(-)
>>
>> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
>> index 8d70417f5125..ebd659af2d78 100644
>> --- a/kernel/sched/fair.c
>> +++ b/kernel/sched/fair.c
>> @@ -9741,10 +9741,8 @@ group_type group_classify(unsigned int imbalance_pct,
>> */
>> static bool sched_use_asym_prio(struct sched_domain *sd, int cpu)
>> {
>> - if (!sched_smt_active())
>> - return true;
>> -
>> - return sd->flags & SD_SHARE_CPUCAPACITY || is_core_idle(cpu);
>> + return (!sched_smt_active()) ||
>> + (sd->flags & SD_SHARE_CPUCAPACITY) || is_core_idle(cpu);
>
> I think that compressing the two conditions into one hurts readability.

Sure, will remove this change.

Thanks
Alex

> As implemented, it is clear that no further checks are required if there
> is no SMT.
>
> Also, please see my comment in patch 6/6.
>