timers: Disable the migration of timers among CPUs

tytydraco · DhineshCool · commit 5698429f7481 · 2024-05-07T18:06:12.000+05:30
Usually, when a timer is created on one CPU, it would be able to be migrated to another CPU. However, this increases realtime latencies and scheduling interrupts. It can be turned off.

Signed-off-by: Tyler Nijmeh &lt;tylernij@gmail.com&gt;
diff --git a/kernel/time/timer.c b/kernel/time/timer.c
@@ -212,7 +212,7 @@ struct timer_base timer_base_deferrable;
 static atomic_t deferrable_pending;
 
 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
-unsigned int sysctl_timer_migration = 1;
+unsigned int sysctl_timer_migration = 0;
 
 void timers_update_migration(bool update_nohz)
 {

Original file line number	Diff line number	Diff line change
`@@ -212,7 +212,7 @@ struct timer_base timer_base_deferrable;`
`212`	`212`	`static atomic_t deferrable_pending;`
`213`	`213`
`214`	`214`	`#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)`
`215`		`-unsigned int sysctl_timer_migration = 1;`
	`215`	`+unsigned int sysctl_timer_migration = 0;`
`216`	`216`
`217`	`217`	`void timers_update_migration(bool update_nohz)`
`218`	`218`	`{`