[PATCH] sched: remove duplicate ifdefs

[PATCH] sched: remove duplicate ifdefs

[Shrikanth Hegde]

when a ifdef is used in the below manner, second one could be considered as
duplicate.

ifdef DEFINE_A
...code block...
ifdef DEFINE_A       <-- This is a duplicate.
...code block...
endif
else
ifndef DEFINE_A     <-- This is also duplicate.
...code block...
endif
endif
More details about the script and methods used to find these code
patterns are in cover letter of [1]

In the scheduler code, there are two places where above pattern can be
observed.
Hunk1: Code is under check of CONFIG_UCLAMP_TASK in kernel/sched/core.c
from line 1353. Hence the same check at line 1795 is duplicate.
Hunk2: Minor update of comment.
Hunk3: Code is already under the check of CONFIG_SMP in
kernel/sched/fair.c from line 8591. Hence the same check in line 10185
is a duplicate.

No functional change is intended here. It only aims to improve code
readability.

[1]:https://lore.kernel.org/all/20240118080326.13137-1-sshegde@linux.ibm.com/
Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
---
Changes since v2:
- Dropped RFC tag.
- Split the patches into individual from the series.
- Added more context to each Hunk for review.

 kernel/sched/core.c | 4 +---
 kernel/sched/fair.c | 2 --
 2 files changed, 1 insertion(+), 5 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 9116bcc90346..a76c7095f736 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1792,7 +1792,6 @@ static void cpu_util_update_eff(struct cgroup_subsys_state *css);
 #endif

 #ifdef CONFIG_SYSCTL
-#ifdef CONFIG_UCLAMP_TASK
 #ifdef CONFIG_UCLAMP_TASK_GROUP
 static void uclamp_update_root_tg(void)
 {
@@ -1898,7 +1897,6 @@ static int sysctl_sched_uclamp_handler(struct ctl_table *table, int write,
 	return result;
 }
 #endif
-#endif

 static int uclamp_validate(struct task_struct *p,
 			   const struct sched_attr *attr)
@@ -2065,7 +2063,7 @@ static void __init init_uclamp(void)
 	}
 }

-#else /* CONFIG_UCLAMP_TASK */
+#else /* !CONFIG_UCLAMP_TASK */
 static inline void uclamp_rq_inc(struct rq *rq, struct task_struct *p) { }
 static inline void uclamp_rq_dec(struct rq *rq, struct task_struct *p) { }
 static inline int uclamp_validate(struct task_struct *p,
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 533547e3c90a..8e30e2bb77a0 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -10182,10 +10182,8 @@ static int idle_cpu_without(int cpu, struct task_struct *p)
 	 * be computed and tested before calling idle_cpu_without().
 	 */

-#ifdef CONFIG_SMP
 	if (rq->ttwu_pending)
 		return 0;
-#endif

 	return 1;
 }
--
2.39.3

Re: [PATCH] sched: remove duplicate ifdefs

[Vincent Guittot]

On Fri, 16 Feb 2024 at 07:14, Shrikanth Hegde <sshegde@linux.ibm.com> wrote:
>
> when a ifdef is used in the below manner, second one could be considered as
> duplicate.
>
> ifdef DEFINE_A
> ...code block...
> ifdef DEFINE_A       <-- This is a duplicate.
> ...code block...
> endif
> else
> ifndef DEFINE_A     <-- This is also duplicate.
> ...code block...
> endif
> endif
> More details about the script and methods used to find these code
> patterns are in cover letter of [1]
>
> In the scheduler code, there are two places where above pattern can be
> observed.
> Hunk1: Code is under check of CONFIG_UCLAMP_TASK in kernel/sched/core.c
> from line 1353. Hence the same check at line 1795 is duplicate.
> Hunk2: Minor update of comment.
> Hunk3: Code is already under the check of CONFIG_SMP in
> kernel/sched/fair.c from line 8591. Hence the same check in line 10185
> is a duplicate.
>
> No functional change is intended here. It only aims to improve code
> readability.
>
> [1]:https://lore.kernel.org/all/20240118080326.13137-1-sshegde@linux.ibm.com/
> Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>

Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>

> ---
> Changes since v2:
> - Dropped RFC tag.
> - Split the patches into individual from the series.
> - Added more context to each Hunk for review.
>
>  kernel/sched/core.c | 4 +---
>  kernel/sched/fair.c | 2 --
>  2 files changed, 1 insertion(+), 5 deletions(-)
>
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index 9116bcc90346..a76c7095f736 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -1792,7 +1792,6 @@ static void cpu_util_update_eff(struct cgroup_subsys_state *css);
>  #endif
>
>  #ifdef CONFIG_SYSCTL
> -#ifdef CONFIG_UCLAMP_TASK
>  #ifdef CONFIG_UCLAMP_TASK_GROUP
>  static void uclamp_update_root_tg(void)
>  {
> @@ -1898,7 +1897,6 @@ static int sysctl_sched_uclamp_handler(struct ctl_table *table, int write,
>         return result;
>  }
>  #endif
> -#endif
>
>  static int uclamp_validate(struct task_struct *p,
>                            const struct sched_attr *attr)
> @@ -2065,7 +2063,7 @@ static void __init init_uclamp(void)
>         }
>  }
>
> -#else /* CONFIG_UCLAMP_TASK */
> +#else /* !CONFIG_UCLAMP_TASK */
>  static inline void uclamp_rq_inc(struct rq *rq, struct task_struct *p) { }
>  static inline void uclamp_rq_dec(struct rq *rq, struct task_struct *p) { }
>  static inline int uclamp_validate(struct task_struct *p,
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 533547e3c90a..8e30e2bb77a0 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -10182,10 +10182,8 @@ static int idle_cpu_without(int cpu, struct task_struct *p)
>          * be computed and tested before calling idle_cpu_without().
>          */
>
> -#ifdef CONFIG_SMP
>         if (rq->ttwu_pending)
>                 return 0;
> -#endif
>
>         return 1;
>  }
> --
> 2.39.3
>

[tip: sched/core] sched/core: Simplify code by removing duplicate #ifdefs

[tip-bot2 for Shrikanth Hegde]

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     8cec3dd9e5930c82c6bd0af3fdb3a36bcd428310
Gitweb:        https://git.kernel.org/tip/8cec3dd9e5930c82c6bd0af3fdb3a36bcd428310
Author:        Shrikanth Hegde <sshegde@linux.ibm.com>
AuthorDate:    Fri, 16 Feb 2024 11:44:33 +05:30
Committer:     Ingo Molnar <mingo@kernel.org>
CommitterDate: Fri, 16 Feb 2024 09:37:15 +01:00

sched/core: Simplify code by removing duplicate #ifdefs

There's a few cases of nested #ifdefs in the scheduler code
that can be simplified:

  #ifdef DEFINE_A
  ...code block...
    #ifdef DEFINE_A       <-- This is a duplicate.
    ...code block...
    #endif
  #else
    #ifndef DEFINE_A     <-- This is also duplicate.
    ...code block...
    #endif
  #endif

More details about the script and methods used to find these code
patterns can be found at:

  https://lore.kernel.org/all/20240118080326.13137-1-sshegde@linux.ibm.com/

No change in functionality intended.

[ mingo: Clarified the changelog. ]

Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20240216061433.535522-1-sshegde@linux.ibm.com
---
 kernel/sched/core.c | 4 +---
 kernel/sched/fair.c | 2 --
 2 files changed, 1 insertion(+), 5 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 9116bcc..a76c709 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1792,7 +1792,6 @@ static void cpu_util_update_eff(struct cgroup_subsys_state *css);
 #endif
 
 #ifdef CONFIG_SYSCTL
-#ifdef CONFIG_UCLAMP_TASK
 #ifdef CONFIG_UCLAMP_TASK_GROUP
 static void uclamp_update_root_tg(void)
 {
@@ -1898,7 +1897,6 @@ undo:
 	return result;
 }
 #endif
-#endif
 
 static int uclamp_validate(struct task_struct *p,
 			   const struct sched_attr *attr)
@@ -2065,7 +2063,7 @@ static void __init init_uclamp(void)
 	}
 }
 
-#else /* CONFIG_UCLAMP_TASK */
+#else /* !CONFIG_UCLAMP_TASK */
 static inline void uclamp_rq_inc(struct rq *rq, struct task_struct *p) { }
 static inline void uclamp_rq_dec(struct rq *rq, struct task_struct *p) { }
 static inline int uclamp_validate(struct task_struct *p,
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 533547e..8e30e2b 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -10182,10 +10182,8 @@ static int idle_cpu_without(int cpu, struct task_struct *p)
 	 * be computed and tested before calling idle_cpu_without().
 	 */
 
-#ifdef CONFIG_SMP
 	if (rq->ttwu_pending)
 		return 0;
-#endif
 
 	return 1;
 }