Merge tag 'sched-core-2023-02-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:

 - Improve the scalability of the CFS bandwidth unthrottling logic with
   large number of CPUs.

 - Fix & rework various cpuidle routines, simplify interaction with the
   generic scheduler code. Add __cpuidle methods as noinstr to objtool's
   noinstr detection and fix boatloads of cpuidle bugs & quirks.

 - Add new ABI: introduce MEMBARRIER_CMD_GET_REGISTRATIONS, to query
   previously issued registrations.

 - Limit scheduler slice duration to the sysctl_sched_latency period, to
   improve scheduling granularity with a large number of SCHED_IDLE
   tasks.

 - Debuggability enhancement on sys_exit(): warn about disabled IRQs,
   but also enable them to prevent a cascade of followup problems and
   repeat warnings.

 - Fix the rescheduling logic in prio_changed_dl().

 - Micro-optimize cpufreq and sched-util methods.

 - Micro-optimize ttwu_runnable()

 - Micro-optimize the idle-scanning in update_numa_stats(),
   select_idle_capacity() and steal_cookie_task().

 - Update the RSEQ code & self-tests

 - Constify various scheduler methods

 - Remove unused methods

 - Refine __init tags

 - Documentation updates

 - Misc other cleanups, fixes

* tag 'sched-core-2023-02-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (110 commits)
  sched/rt: pick_next_rt_entity(): check list_entry
  sched/deadline: Add more reschedule cases to prio_changed_dl()
  sched/fair: sanitize vruntime of entity being placed
  sched/fair: Remove capacity inversion detection
  sched/fair: unlink misfit task from cpu overutilized
  objtool: mem*() are not uaccess safe
  cpuidle: Fix poll_idle() noinstr annotation
  sched/clock: Make local_clock() noinstr
  sched/clock/x86: Mark sched_clock() noinstr
  x86/pvclock: Improve atomic update of last_value in pvclock_clocksource_read()
  x86/atomics: Always inline arch_atomic64*()
  cpuidle: tracing, preempt: Squash _rcuidle tracing
  cpuidle: tracing: Warn about !rcu_is_watching()
  cpuidle: lib/bug: Disable rcu_is_watching() during WARN/BUG
  cpuidle: drivers: firmware: psci: Dont instrument suspend code
  KVM: selftests: Fix build of rseq test
  exit: Detect and fix irq disabled state in oops
  cpuidle, arm64: Fix the ARM64 cpuidle logic
  cpuidle: mvebu: Fix duplicate flags assignment
  sched/fair: Limit sched slice duration
  ...

1 files changed, 32 insertions, 33 deletions

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 40d156a31676..e57cd31bfec4 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -24,6 +24,7 @@
 #include <linux/cpuidle.h>
 #include <linux/acpi.h>
 #include <linux/elf-randomize.h>
+#include <linux/static_call.h>
 #include <trace/events/power.h>
 #include <linux/hw_breakpoint.h>
 #include <asm/cpu.h>
@@ -694,7 +695,24 @@ void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p)
 unsigned long boot_option_idle_override = IDLE_NO_OVERRIDE;
 EXPORT_SYMBOL(boot_option_idle_override);
 
-static void (*x86_idle)(void);
+/*
+ * We use this if we don't have any better idle routine..
+ */
+void __cpuidle default_idle(void)
+{
+	raw_safe_halt();
+	raw_local_irq_disable();
+}
+#if defined(CONFIG_APM_MODULE) || defined(CONFIG_HALTPOLL_CPUIDLE_MODULE)
+EXPORT_SYMBOL(default_idle);
+#endif
+
+DEFINE_STATIC_CALL_NULL(x86_idle, default_idle);
+
+static bool x86_idle_set(void)
+{
+	return !!static_call_query(x86_idle);
+}
 
 #ifndef CONFIG_SMP
 static inline void play_dead(void)
@@ -717,28 +735,17 @@ void arch_cpu_idle_dead(void)
 /*
  * Called from the generic idle code.
  */
-void arch_cpu_idle(void)
-{
-	x86_idle();
-}
-
-/*
- * We use this if we don't have any better idle routine..
- */
-void __cpuidle default_idle(void)
+void __cpuidle arch_cpu_idle(void)
 {
-	raw_safe_halt();
+	static_call(x86_idle)();
 }
-#if defined(CONFIG_APM_MODULE) || defined(CONFIG_HALTPOLL_CPUIDLE_MODULE)
-EXPORT_SYMBOL(default_idle);
-#endif
 
 #ifdef CONFIG_XEN
 bool xen_set_default_idle(void)
 {
-	bool ret = !!x86_idle;
+	bool ret = x86_idle_set();
 
-	x86_idle = default_idle;
+	static_call_update(x86_idle, default_idle);
 
 	return ret;
 }
@@ -800,13 +807,7 @@ static void amd_e400_idle(void)
 
 	default_idle();
 
-	/*
-	 * The switch back from broadcast mode needs to be called with
-	 * interrupts disabled.
-	 */
-	raw_local_irq_disable();
 	tick_broadcast_exit();
-	raw_local_irq_enable();
 }
 
 /*
@@ -864,12 +865,10 @@ static __cpuidle void mwait_idle(void)
 		}
 
 		__monitor((void *)&current_thread_info()->flags, 0, 0);
-		if (!need_resched())
+		if (!need_resched()) {
 			__sti_mwait(0, 0);
-		else
-			raw_local_irq_enable();
-	} else {
-		raw_local_irq_enable();
+			raw_local_irq_disable();
+		}
 	}
 	__current_clr_polling();
 }
@@ -880,20 +879,20 @@ void select_idle_routine(const struct cpuinfo_x86 *c)
 	if (boot_option_idle_override == IDLE_POLL && smp_num_siblings > 1)
 		pr_warn_once("WARNING: polling idle and HT enabled, performance may degrade\n");
 #endif
-	if (x86_idle || boot_option_idle_override == IDLE_POLL)
+	if (x86_idle_set() || boot_option_idle_override == IDLE_POLL)
 		return;
 
 	if (boot_cpu_has_bug(X86_BUG_AMD_E400)) {
 		pr_info("using AMD E400 aware idle routine\n");
-		x86_idle = amd_e400_idle;
+		static_call_update(x86_idle, amd_e400_idle);
 	} else if (prefer_mwait_c1_over_halt(c)) {
 		pr_info("using mwait in idle threads\n");
-		x86_idle = mwait_idle;
+		static_call_update(x86_idle, mwait_idle);
 	} else if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST)) {
 		pr_info("using TDX aware idle routine\n");
-		x86_idle = tdx_safe_halt;
+		static_call_update(x86_idle, tdx_safe_halt);
 	} else
-		x86_idle = default_idle;
+		static_call_update(x86_idle, default_idle);
 }
 
 void amd_e400_c1e_apic_setup(void)
@@ -946,7 +945,7 @@ static int __init idle_setup(char *str)
 		 * To continue to load the CPU idle driver, don't touch
 		 * the boot_option_idle_override.
 		 */
-		x86_idle = default_idle;
+		static_call_update(x86_idle, default_idle);
 		boot_option_idle_override = IDLE_HALT;
 	} else if (!strcmp(str, "nomwait")) {
 		/*