[PATCH] x86: remove dead code

[PATCH] x86: remove dead code

[Jan Beulich]

Neither __cpu_disable() nor __cpu_die() are being referenced without
CONFIG_HOTPLUG_CPU.

Signed-off-by: Jan Beulich <jbeulich@novell.com>

 arch/x86/kernel/smpboot_32.c |   11 -----------
 arch/x86/kernel/smpboot_64.c |   12 ------------
 2 files changed, 23 deletions(-)

--- linux-2.6.24-rc5/arch/x86/kernel/smpboot_32.c	2007-12-12 11:28:18.000000000 +0100
+++ 2.6.24-rc5-x86-cpu-die/arch/x86/kernel/smpboot_32.c	2007-12-07 16:12:01.000000000 +0100
@@ -1232,17 +1232,6 @@ void __cpu_die(unsigned int cpu)
 	}
  	printk(KERN_ERR "CPU %u didn't die...\n", cpu);
 }
-#else /* ... !CONFIG_HOTPLUG_CPU */
-int __cpu_disable(void)
-{
-	return -ENOSYS;
-}
-
-void __cpu_die(unsigned int cpu)
-{
-	/* We said "no" in __cpu_disable */
-	BUG();
-}
 #endif /* CONFIG_HOTPLUG_CPU */
 
 int __cpuinit native_cpu_up(unsigned int cpu)
--- linux-2.6.24-rc5/arch/x86/kernel/smpboot_64.c	2007-12-12 11:28:18.000000000 +0100
+++ 2.6.24-rc5-x86-cpu-die/arch/x86/kernel/smpboot_64.c	2007-12-07 16:12:17.000000000 +0100
@@ -1084,16 +1084,4 @@ static __init int setup_additional_cpus(
 }
 early_param("additional_cpus", setup_additional_cpus);
 
-#else /* ... !CONFIG_HOTPLUG_CPU */
-
-int __cpu_disable(void)
-{
-	return -ENOSYS;
-}
-
-void __cpu_die(unsigned int cpu)
-{
-	/* We said "no" in __cpu_disable */
-	BUG();
-}
 #endif /* CONFIG_HOTPLUG_CPU */

[PATCH] x86 : remove dead code

[Daniel Lezcano]

The hlt_use_halt function returns always true and there is only
one definition of it.

The default_idle function can then get ride of the if ... statement and
we can remove the else branch.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 arch/x86/kernel/process.c |   39 ++++++++++++++-------------------------
 1 files changed, 14 insertions(+), 25 deletions(-)

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index b644e1c..2f99e31 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -306,11 +306,6 @@ void (*pm_idle)(void);
 EXPORT_SYMBOL(pm_idle);
 #endif
 
-static inline int hlt_use_halt(void)
-{
-	return 1;
-}
-
 #ifndef CONFIG_SMP
 static inline void play_dead(void)
 {
@@ -410,28 +405,22 @@ void cpu_idle(void)
  */
 void default_idle(void)
 {
-	if (hlt_use_halt()) {
-		trace_power_start_rcuidle(POWER_CSTATE, 1, smp_processor_id());
-		trace_cpu_idle_rcuidle(1, smp_processor_id());
-		current_thread_info()->status &= ~TS_POLLING;
-		/*
-		 * TS_POLLING-cleared state must be visible before we
-		 * test NEED_RESCHED:
-		 */
-		smp_mb();
+	trace_power_start_rcuidle(POWER_CSTATE, 1, smp_processor_id());
+	trace_cpu_idle_rcuidle(1, smp_processor_id());
+	current_thread_info()->status &= ~TS_POLLING;
+	/*
+	 * TS_POLLING-cleared state must be visible before we
+	 * test NEED_RESCHED:
+	 */
+	smp_mb();
 
-		if (!need_resched())
-			safe_halt();	/* enables interrupts racelessly */
-		else
-			local_irq_enable();
-		current_thread_info()->status |= TS_POLLING;
-		trace_power_end_rcuidle(smp_processor_id());
-		trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
-	} else {
+	if (!need_resched())
+		safe_halt();	/* enables interrupts racelessly */
+	else
 		local_irq_enable();
-		/* loop is done by the caller */
-		cpu_relax();
-	}
+	current_thread_info()->status |= TS_POLLING;
+	trace_power_end_rcuidle(smp_processor_id());
+	trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
 }
 #ifdef CONFIG_APM_MODULE
 EXPORT_SYMBOL(default_idle);
-- 
1.7.5.4