linux-kernel - [PATCH v3 06/57] sched: Simplify sysctl_sched_uclamp

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Message-ID: <20230612093537.833273038@infradead.org>
Date:   Mon, 12 Jun 2023 11:07:19 +0200
From:   Peter Zijlstra <peterz@...radead.org>
To:     torvalds@...ux-foundation.org, keescook@...omium.org,
        gregkh@...uxfoundation.org, pbonzini@...hat.com
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Subject: [PATCH v3 06/57] sched: Simplify sysctl_sched_uclamp_handler()

Use guards to reduce gotos and simplify control flow.

Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
---
 kernel/sched/core.c |   11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1801,7 +1801,8 @@ static int sysctl_sched_uclamp_handler(s
 	int old_min, old_max, old_min_rt;
 	int result;
 
-	mutex_lock(&uclamp_mutex);
+	guard(mutex)(&uclamp_mutex);
+
 	old_min = sysctl_sched_uclamp_util_min;
 	old_max = sysctl_sched_uclamp_util_max;
 	old_min_rt = sysctl_sched_uclamp_util_min_rt_default;
@@ -1810,7 +1811,7 @@ static int sysctl_sched_uclamp_handler(s
 	if (result)
 		goto undo;
 	if (!write)
-		goto done;
+		return result;
 
 	if (sysctl_sched_uclamp_util_min > sysctl_sched_uclamp_util_max ||
 	    sysctl_sched_uclamp_util_max > SCHED_CAPACITY_SCALE	||
@@ -1846,16 +1847,12 @@ static int sysctl_sched_uclamp_handler(s
 	 * Otherwise, keep it simple and do just a lazy update at each next
 	 * task enqueue time.
 	 */
-
-	goto done;
+	return result;
 
 undo:
 	sysctl_sched_uclamp_util_min = old_min;
 	sysctl_sched_uclamp_util_max = old_max;
 	sysctl_sched_uclamp_util_min_rt_default = old_min_rt;
-done:
-	mutex_unlock(&uclamp_mutex);
-
 	return result;
 }
 #endif