[tip: timers/core] timers: Move timer sysctl into the timer code

["tip-bot2 for tangmeng" <tip-bot2@linutronix.de>]

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

Commit-ID:     efaa0227f6c6a5073951b20cf2f8c63c4155306c
Gitweb:        https://git.kernel.org/tip/efaa0227f6c6a5073951b20cf2f8c63c4155306c
Author:        tangmeng <tangmeng@uniontech.com>
AuthorDate:    Tue, 15 Feb 2022 14:50:19 +08:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Sun, 10 Apr 2022 12:38:45 +02:00

timers: Move timer sysctl into the timer code

This is part of the effort to reduce kernel/sysctl.c to only contain the
core logic.

Signed-off-by: tangmeng <tangmeng@uniontech.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220215065019.7520-1-tangmeng@uniontech.com

---
 include/linux/timer.h |  8 +------
 kernel/sysctl.c       | 11 +---------
 kernel/time/timer.c   | 53 ++++++++++++++++++++++++++++++------------
 3 files changed, 38 insertions(+), 34 deletions(-)

diff --git a/include/linux/timer.h b/include/linux/timer.h
index fda13c9..648f001 100644
--- a/include/linux/timer.h
+++ b/include/linux/timer.h
@@ -196,14 +196,6 @@ extern void init_timers(void);
 struct hrtimer;
 extern enum hrtimer_restart it_real_fn(struct hrtimer *);
 
-#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
-struct ctl_table;
-
-extern unsigned int sysctl_timer_migration;
-int timer_migration_handler(struct ctl_table *table, int write,
-			    void *buffer, size_t *lenp, loff_t *ppos);
-#endif
-
 unsigned long __round_jiffies(unsigned long j, int cpu);
 unsigned long __round_jiffies_relative(unsigned long j, int cpu);
 unsigned long round_jiffies(unsigned long j);
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 830aaf8..5b7b1a8 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2288,17 +2288,6 @@ static struct ctl_table kern_table[] = {
 		.extra1		= SYSCTL_ZERO,
 		.extra2		= SYSCTL_ONE,
 	},
-#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
-	{
-		.procname	= "timer_migration",
-		.data		= &sysctl_timer_migration,
-		.maxlen		= sizeof(unsigned int),
-		.mode		= 0644,
-		.proc_handler	= timer_migration_handler,
-		.extra1		= SYSCTL_ZERO,
-		.extra2		= SYSCTL_ONE,
-	},
-#endif
 #ifdef CONFIG_BPF_SYSCALL
 	{
 		.procname	= "unprivileged_bpf_disabled",
diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index 60aebf2..ef082d4 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -44,6 +44,7 @@
 #include <linux/slab.h>
 #include <linux/compat.h>
 #include <linux/random.h>
+#include <linux/sysctl.h>
 
 #include <linux/uaccess.h>
 #include <asm/unistd.h>
@@ -223,7 +224,7 @@ static void timer_update_keys(struct work_struct *work);
 static DECLARE_WORK(timer_update_work, timer_update_keys);
 
 #ifdef CONFIG_SMP
-unsigned int sysctl_timer_migration = 1;
+static unsigned int sysctl_timer_migration = 1;
 
 DEFINE_STATIC_KEY_FALSE(timers_migration_enabled);
 
@@ -234,7 +235,42 @@ static void timers_update_migration(void)
 	else
 		static_branch_disable(&timers_migration_enabled);
 }
-#else
+
+#ifdef CONFIG_SYSCTL
+static int timer_migration_handler(struct ctl_table *table, int write,
+			    void *buffer, size_t *lenp, loff_t *ppos)
+{
+	int ret;
+
+	mutex_lock(&timer_keys_mutex);
+	ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
+	if (!ret && write)
+		timers_update_migration();
+	mutex_unlock(&timer_keys_mutex);
+	return ret;
+}
+
+static struct ctl_table timer_sysctl[] = {
+	{
+		.procname	= "timer_migration",
+		.data		= &sysctl_timer_migration,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= timer_migration_handler,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_ONE,
+	},
+	{}
+};
+
+static int __init timer_sysctl_init(void)
+{
+	register_sysctl("kernel", timer_sysctl);
+	return 0;
+}
+device_initcall(timer_sysctl_init);
+#endif /* CONFIG_SYSCTL */
+#else /* CONFIG_SMP */
 static inline void timers_update_migration(void) { }
 #endif /* !CONFIG_SMP */
 
@@ -251,19 +287,6 @@ void timers_update_nohz(void)
 	schedule_work(&timer_update_work);
 }
 
-int timer_migration_handler(struct ctl_table *table, int write,
-			    void *buffer, size_t *lenp, loff_t *ppos)
-{
-	int ret;
-
-	mutex_lock(&timer_keys_mutex);
-	ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
-	if (!ret && write)
-		timers_update_migration();
-	mutex_unlock(&timer_keys_mutex);
-	return ret;
-}
-
 static inline bool is_timers_nohz_active(void)
 {
 	return static_branch_unlikely(&timers_nohz_active);