[tip: sched/core] sched/topology: Wrappers for sched_domains_mutex

[tip-bot2 for Juri Lelli]

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

Commit-ID:     56209334dda1832c0a919e1d74768c6d0f3b2ca9
Gitweb:        https://git.kernel.org/tip/56209334dda1832c0a919e1d74768c6d0f3b2ca9
Author:        Juri Lelli <juri.lelli@xxxxxxxxxx>
AuthorDate:    Thu, 13 Mar 2025 18:03:32 +01:00
Committer:     Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Mon, 17 Mar 2025 11:23:41 +01:00

sched/topology: Wrappers for sched_domains_mutex

Create wrappers for sched_domains_mutex so that it can transparently be
used on both CONFIG_SMP and !CONFIG_SMP, as some function will need to
do.

Fixes: 53916d5fd3c0 ("sched/deadline: Check bandwidth overflow earlier for hotplug")
Reported-by: Jon Hunter <jonathanh@xxxxxxxxxx>
Signed-off-by: Juri Lelli <juri.lelli@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Valentin Schneider <vschneid@xxxxxxxxxx>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@xxxxxxx>
Tested-by: Waiman Long <longman@xxxxxxxxxx>
Tested-by: Jon Hunter <jonathanh@xxxxxxxxxx>
Tested-by: Dietmar Eggemann <dietmar.eggemann@xxxxxxx>
Link: https://lore.kernel.org/r/Z9MP5Oq9RB8jBs3y@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
---
 include/linux/sched.h   |  5 +++++
 kernel/cgroup/cpuset.c  |  4 ++--
 kernel/sched/core.c     |  4 ++--
 kernel/sched/debug.c    |  8 ++++----
 kernel/sched/topology.c | 12 ++++++++++--
 5 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 9632e33..0785268 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -382,6 +382,11 @@ enum uclamp_id {
 #ifdef CONFIG_SMP
 extern struct root_domain def_root_domain;
 extern struct mutex sched_domains_mutex;
+extern void sched_domains_mutex_lock(void);
+extern void sched_domains_mutex_unlock(void);
+#else
+static inline void sched_domains_mutex_lock(void) { }
+static inline void sched_domains_mutex_unlock(void) { }
 #endif
 
 struct sched_param {
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index 0f910c8..f87526e 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -994,10 +994,10 @@ static void
 partition_and_rebuild_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
 				    struct sched_domain_attr *dattr_new)
 {
-	mutex_lock(&sched_domains_mutex);
+	sched_domains_mutex_lock();
 	partition_sched_domains_locked(ndoms_new, doms_new, dattr_new);
 	dl_rebuild_rd_accounting();
-	mutex_unlock(&sched_domains_mutex);
+	sched_domains_mutex_unlock();
 }
 
 /*
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index c734724..84f6800 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -8470,9 +8470,9 @@ void __init sched_init_smp(void)
 	 * CPU masks are stable and all blatant races in the below code cannot
 	 * happen.
 	 */
-	mutex_lock(&sched_domains_mutex);
+	sched_domains_mutex_lock();
 	sched_init_domains(cpu_active_mask);
-	mutex_unlock(&sched_domains_mutex);
+	sched_domains_mutex_unlock();
 
 	/* Move init over to a non-isolated CPU */
 	if (set_cpus_allowed_ptr(current, housekeeping_cpumask(HK_TYPE_DOMAIN)) < 0)
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 39be739..56ae54e 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -294,7 +294,7 @@ static ssize_t sched_verbose_write(struct file *filp, const char __user *ubuf,
 	bool orig;
 
 	cpus_read_lock();
-	mutex_lock(&sched_domains_mutex);
+	sched_domains_mutex_lock();
 
 	orig = sched_debug_verbose;
 	result = debugfs_write_file_bool(filp, ubuf, cnt, ppos);
@@ -306,7 +306,7 @@ static ssize_t sched_verbose_write(struct file *filp, const char __user *ubuf,
 		sd_dentry = NULL;
 	}
 
-	mutex_unlock(&sched_domains_mutex);
+	sched_domains_mutex_unlock();
 	cpus_read_unlock();
 
 	return result;
@@ -517,9 +517,9 @@ static __init int sched_init_debug(void)
 	debugfs_create_u32("migration_cost_ns", 0644, debugfs_sched, &sysctl_sched_migration_cost);
 	debugfs_create_u32("nr_migrate", 0644, debugfs_sched, &sysctl_sched_nr_migrate);
 
-	mutex_lock(&sched_domains_mutex);
+	sched_domains_mutex_lock();
 	update_sched_domain_debugfs();
-	mutex_unlock(&sched_domains_mutex);
+	sched_domains_mutex_unlock();
 #endif
 
 #ifdef CONFIG_NUMA_BALANCING
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index c49aea8..296ff2a 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -6,6 +6,14 @@
 #include <linux/bsearch.h>
 
 DEFINE_MUTEX(sched_domains_mutex);
+void sched_domains_mutex_lock(void)
+{
+	mutex_lock(&sched_domains_mutex);
+}
+void sched_domains_mutex_unlock(void)
+{
+	mutex_unlock(&sched_domains_mutex);
+}
 
 /* Protected by sched_domains_mutex: */
 static cpumask_var_t sched_domains_tmpmask;
@@ -2791,7 +2799,7 @@ match3:
 void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
 			     struct sched_domain_attr *dattr_new)
 {
-	mutex_lock(&sched_domains_mutex);
+	sched_domains_mutex_lock();
 	partition_sched_domains_locked(ndoms_new, doms_new, dattr_new);
-	mutex_unlock(&sched_domains_mutex);
+	sched_domains_mutex_unlock();
 }