diff mbox series

[v3,4/4] sched/fair: Check the SD_ASYM_PACKING flag in sched_use_asym_prio()

Message ID 20240201115447.522627-4-alexs@kernel.org
State New
Headers
Series [v3,1/4] sched/fair: add SD_CLUSTER in comments |

Commit Message

alexs@kernel.org Feb. 1, 2024, 11:54 a.m. UTC 
  From: Alex Shi <alexs@kernel.org>

sched_use_asym_prio() checks whether CPU priorities should be used. It
makes sense to check for the SD_ASYM_PACKING() inside the function.
Since both sched_asym() and sched_group_asym() use sched_use_asym_prio(),
remove the now superfluous checks for the flag in various places"

Signed-off-by: Alex Shi <alexs@kernel.org>
To: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
To: Ben Segall <bsegall@google.com>
To: Steven Rostedt <rostedt@goodmis.org>
To: Dietmar Eggemann <dietmar.eggemann@arm.com>
To: Valentin Schneider <vschneid@redhat.com>
To: Daniel Bristot de Oliveira <bristot@redhat.com>
To: Vincent Guittot <vincent.guittot@linaro.org>
To: Juri Lelli <juri.lelli@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
To: Ingo Molnar <mingo@redhat.com>
---
 kernel/sched/fair.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

Comments

Ricardo Neri Feb. 5, 2024, 10:38 p.m. UTC | #1 
On Thu, Feb 01, 2024 at 07:54:47PM +0800, alexs@kernel.org wrote:
> From: Alex Shi <alexs@kernel.org>
> 
> sched_use_asym_prio() checks whether CPU priorities should be used. It
> makes sense to check for the SD_ASYM_PACKING() inside the function.
> Since both sched_asym() and sched_group_asym() use sched_use_asym_prio(),
> remove the now superfluous checks for the flag in various places"

s/places"/places./

> 
> Signed-off-by: Alex Shi <alexs@kernel.org>
> To: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
> To: Ben Segall <bsegall@google.com>
> To: Steven Rostedt <rostedt@goodmis.org>
> To: Dietmar Eggemann <dietmar.eggemann@arm.com>
> To: Valentin Schneider <vschneid@redhat.com>
> To: Daniel Bristot de Oliveira <bristot@redhat.com>
> To: Vincent Guittot <vincent.guittot@linaro.org>
> To: Juri Lelli <juri.lelli@redhat.com>
> To: Peter Zijlstra <peterz@infradead.org>
> To: Ingo Molnar <mingo@redhat.com>
> ---
>  kernel/sched/fair.c | 15 +++++++--------
>  1 file changed, 7 insertions(+), 8 deletions(-)
> 
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 44fd5e2ca642..bd32efbea688 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -9741,6 +9741,9 @@ group_type group_classify(unsigned int imbalance_pct,
>   */
>  static bool sched_use_asym_prio(struct sched_domain *sd, int cpu)
>  {
> +	if (!(sd->flags & SD_ASYM_PACKING))
> +		return false;
> +
>  	if (!sched_smt_active())
>  		return true;
>  
> @@ -9940,11 +9943,9 @@ static inline void update_sg_lb_stats(struct lb_env *env,
>  	sgs->group_weight = group->group_weight;
>  
>  	/* Check if dst CPU is idle and preferred to this group */
> -	if (!local_group && env->sd->flags & SD_ASYM_PACKING &&
> -	    env->idle != CPU_NOT_IDLE && sgs->sum_h_nr_running &&
> -	    sched_group_asym(env, sgs, group)) {
> +	if (!local_group && env->idle != CPU_NOT_IDLE && sgs->sum_h_nr_running &&
> +			sched_group_asym(env, sgs, group))

You should align sched_group_asym() to !local_group.

>  		sgs->group_asym_packing = 1;
> -	}
>  
>  	/* Check for loaded SMT group to be balanced to dst CPU */
>  	if (!local_group && smt_balance(env, sgs, group))
> @@ -11040,9 +11041,7 @@ static struct rq *find_busiest_queue(struct lb_env *env,
>  		 * If balancing between cores, let lower priority CPUs help
>  		 * SMT cores with more than one busy sibling.
>  		 */
> -		if ((env->sd->flags & SD_ASYM_PACKING) &&
> -		    sched_asym(env->sd, i, env->dst_cpu) &&
> -		    nr_running == 1)
> +		if (sched_asym(env->sd, i, env->dst_cpu) && nr_running == 1)
>  			continue;
>  
>  		switch (env->migration_type) {
> @@ -11138,7 +11137,7 @@ asym_active_balance(struct lb_env *env)
>  	 * the lower priority @env::dst_cpu help it. Do not follow
>  	 * CPU priority.
>  	 */
> -	return env->idle != CPU_NOT_IDLE && (env->sd->flags & SD_ASYM_PACKING) &&
> +	return env->idle != CPU_NOT_IDLE &&
>  	       sched_use_asym_prio(env->sd, env->dst_cpu) &&
>  	       (sched_asym_prefer(env->dst_cpu, env->src_cpu) ||

Perhaps you can rearrange the spaghetti of conditions to make better use of
the full 80-column line.
kuiliang Shi Feb. 6, 2024, 7:57 a.m. UTC | #2 
On 2/6/24 6:38 AM, Ricardo Neri wrote:
> On Thu, Feb 01, 2024 at 07:54:47PM +0800, alexs@kernel.org wrote:
>> From: Alex Shi <alexs@kernel.org>
>>
>> sched_use_asym_prio() checks whether CPU priorities should be used. It
>> makes sense to check for the SD_ASYM_PACKING() inside the function.
>> Since both sched_asym() and sched_group_asym() use sched_use_asym_prio(),
>> remove the now superfluous checks for the flag in various places"
> 
> s/places"/places./
> 
>>
>> Signed-off-by: Alex Shi <alexs@kernel.org>
>> To: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
>> To: Ben Segall <bsegall@google.com>
>> To: Steven Rostedt <rostedt@goodmis.org>
>> To: Dietmar Eggemann <dietmar.eggemann@arm.com>
>> To: Valentin Schneider <vschneid@redhat.com>
>> To: Daniel Bristot de Oliveira <bristot@redhat.com>
>> To: Vincent Guittot <vincent.guittot@linaro.org>
>> To: Juri Lelli <juri.lelli@redhat.com>
>> To: Peter Zijlstra <peterz@infradead.org>
>> To: Ingo Molnar <mingo@redhat.com>
>> ---
>>  kernel/sched/fair.c | 15 +++++++--------
>>  1 file changed, 7 insertions(+), 8 deletions(-)
>>
>> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
>> index 44fd5e2ca642..bd32efbea688 100644
>> --- a/kernel/sched/fair.c
>> +++ b/kernel/sched/fair.c
>> @@ -9741,6 +9741,9 @@ group_type group_classify(unsigned int imbalance_pct,
>>   */
>>  static bool sched_use_asym_prio(struct sched_domain *sd, int cpu)
>>  {
>> +	if (!(sd->flags & SD_ASYM_PACKING))
>> +		return false;
>> +
>>  	if (!sched_smt_active())
>>  		return true;
>>  
>> @@ -9940,11 +9943,9 @@ static inline void update_sg_lb_stats(struct lb_env *env,
>>  	sgs->group_weight = group->group_weight;
>>  
>>  	/* Check if dst CPU is idle and preferred to this group */
>> -	if (!local_group && env->sd->flags & SD_ASYM_PACKING &&
>> -	    env->idle != CPU_NOT_IDLE && sgs->sum_h_nr_running &&
>> -	    sched_group_asym(env, sgs, group)) {
>> +	if (!local_group && env->idle != CPU_NOT_IDLE && sgs->sum_h_nr_running &&
>> +			sched_group_asym(env, sgs, group))
> 
> You should align sched_group_asym() to !local_group.

Thanks for all suggestion. I will take them in next version.

> 
>>  		sgs->group_asym_packing = 1;
>> -	}
>>  
>>  	/* Check for loaded SMT group to be balanced to dst CPU */
>>  	if (!local_group && smt_balance(env, sgs, group))
>> @@ -11040,9 +11041,7 @@ static struct rq *find_busiest_queue(struct lb_env *env,
>>  		 * If balancing between cores, let lower priority CPUs help
>>  		 * SMT cores with more than one busy sibling.
>>  		 */
>> -		if ((env->sd->flags & SD_ASYM_PACKING) &&
>> -		    sched_asym(env->sd, i, env->dst_cpu) &&
>> -		    nr_running == 1)
>> +		if (sched_asym(env->sd, i, env->dst_cpu) && nr_running == 1)
>>  			continue;
>>  
>>  		switch (env->migration_type) {
>> @@ -11138,7 +11137,7 @@ asym_active_balance(struct lb_env *env)
>>  	 * the lower priority @env::dst_cpu help it. Do not follow
>>  	 * CPU priority.
>>  	 */
>> -	return env->idle != CPU_NOT_IDLE && (env->sd->flags & SD_ASYM_PACKING) &&
>> +	return env->idle != CPU_NOT_IDLE &&
>>  	       sched_use_asym_prio(env->sd, env->dst_cpu) &&
>>  	       (sched_asym_prefer(env->dst_cpu, env->src_cpu) ||
> 
> Perhaps you can rearrange the spaghetti of conditions to make better use of
> the full 80-column line.

80-column doesn't work here, will try 100 column.

Thanks
Alex
diff mbox series

Patch

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 44fd5e2ca642..bd32efbea688 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -9741,6 +9741,9 @@  group_type group_classify(unsigned int imbalance_pct,
  */
 static bool sched_use_asym_prio(struct sched_domain *sd, int cpu)
 {
+	if (!(sd->flags & SD_ASYM_PACKING))
+		return false;
+
 	if (!sched_smt_active())
 		return true;
 
@@ -9940,11 +9943,9 @@  static inline void update_sg_lb_stats(struct lb_env *env,
 	sgs->group_weight = group->group_weight;
 
 	/* Check if dst CPU is idle and preferred to this group */
-	if (!local_group && env->sd->flags & SD_ASYM_PACKING &&
-	    env->idle != CPU_NOT_IDLE && sgs->sum_h_nr_running &&
-	    sched_group_asym(env, sgs, group)) {
+	if (!local_group && env->idle != CPU_NOT_IDLE && sgs->sum_h_nr_running &&
+			sched_group_asym(env, sgs, group))
 		sgs->group_asym_packing = 1;
-	}
 
 	/* Check for loaded SMT group to be balanced to dst CPU */
 	if (!local_group && smt_balance(env, sgs, group))
@@ -11040,9 +11041,7 @@  static struct rq *find_busiest_queue(struct lb_env *env,
 		 * If balancing between cores, let lower priority CPUs help
 		 * SMT cores with more than one busy sibling.
 		 */
-		if ((env->sd->flags & SD_ASYM_PACKING) &&
-		    sched_asym(env->sd, i, env->dst_cpu) &&
-		    nr_running == 1)
+		if (sched_asym(env->sd, i, env->dst_cpu) && nr_running == 1)
 			continue;
 
 		switch (env->migration_type) {
@@ -11138,7 +11137,7 @@  asym_active_balance(struct lb_env *env)
 	 * the lower priority @env::dst_cpu help it. Do not follow
 	 * CPU priority.
 	 */
-	return env->idle != CPU_NOT_IDLE && (env->sd->flags & SD_ASYM_PACKING) &&
+	return env->idle != CPU_NOT_IDLE &&
 	       sched_use_asym_prio(env->sd, env->dst_cpu) &&
 	       (sched_asym_prefer(env->dst_cpu, env->src_cpu) ||
 		!sched_use_asym_prio(env->sd, env->src_cpu));