linux-kernel - [PATCH] sched: remove duplicate ifdefs

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Date: Fri, 16 Feb 2024 11:44:33 +0530
From: Shrikanth Hegde <sshegde@...ux.ibm.com>
To: mingo@...nel.org, peterz@...radead.org, vincent.guittot@...aro.org
Cc: sshegde@...ux.vnet.ibm.com, linux-kernel@...r.kernel.org
Subject: [PATCH] sched: remove duplicate ifdefs

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@...ux.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