linux-kernel - [PATCH 5/5] x86: remove enter_idle(), exit

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Date:   Fri, 18 Nov 2016 01:23:21 -0500
From:   Len Brown <lenb@...nel.org>
To:     x86@...nel.org
Cc:     linux-kernel@...r.kernel.org, Len Brown <len.brown@...el.com>
Subject: [PATCH 5/5] x86: remove enter_idle(), exit_idle()

From: Len Brown <len.brown@...el.com>

Upon removal of the is_idle flag, these routines became NOPs.

Signed-off-by: Len Brown <len.brown@...el.com>
Acked-by: Peter Zijlstra (Intel) <peterz@...radead.org>
---
 arch/x86/include/asm/apic.h      |  1 -
 arch/x86/include/asm/idle.h      |  9 ---------
 arch/x86/kernel/kvm.c            |  2 --
 arch/x86/kernel/process.c        | 25 -------------------------
 drivers/xen/events/events_base.c |  1 -
 5 files changed, 38 deletions(-)

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index f5aaf6c83222..5731274bfdba 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -639,7 +639,6 @@ extern void irq_exit(void);
 static inline void entering_irq(void)
 {
 	irq_enter();
-	exit_idle();
 }
 
 static inline void entering_ack_irq(void)
diff --git a/arch/x86/include/asm/idle.h b/arch/x86/include/asm/idle.h
index 02bab09707f2..dcebb1c634f1 100644
--- a/arch/x86/include/asm/idle.h
+++ b/arch/x86/include/asm/idle.h
@@ -1,15 +1,6 @@
 #ifndef _ASM_X86_IDLE_H
 #define _ASM_X86_IDLE_H
 
-#ifdef CONFIG_X86_64
-void enter_idle(void);
-void exit_idle(void);
-#else /* !CONFIG_X86_64 */
-static inline void enter_idle(void) { }
-static inline void exit_idle(void) { }
-static inline void __exit_idle(void) { }
-#endif /* CONFIG_X86_64 */
-
 void amd_e400_remove_cpu(int cpu);
 
 #endif /* _ASM_X86_IDLE_H */
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index edbbfc854e39..093f550f372d 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -267,13 +267,11 @@ do_async_page_fault(struct pt_regs *regs, unsigned long error_code)
 	case KVM_PV_REASON_PAGE_NOT_PRESENT:
 		/* page is swapped out by the host. */
 		prev_state = exception_enter();
-		exit_idle();
 		kvm_async_pf_task_wait((u32)read_cr2());
 		exception_exit(prev_state);
 		break;
 	case KVM_PV_REASON_PAGE_READY:
 		rcu_irq_enter();
-		exit_idle();
 		kvm_async_pf_task_wake((u32)read_cr2());
 		rcu_irq_exit();
 		break;
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index d8e9d794e114..ee023919e476 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -234,34 +234,9 @@ static inline void play_dead(void)
 }
 #endif
 
-#ifdef CONFIG_X86_64
-void enter_idle(void)
-{
-}
-
-static void __exit_idle(void)
-{
-}
-
-/* Called from interrupts to signify idle end */
-void exit_idle(void)
-{
-	/* idle loop has pid 0 */
-	if (current->pid)
-		return;
-	__exit_idle();
-}
-#endif
-
 void arch_cpu_idle_enter(void)
 {
 	local_touch_nmi();
-	enter_idle();
-}
-
-void arch_cpu_idle_exit(void)
-{
-	__exit_idle();
 }
 
 void arch_cpu_idle_dead(void)
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index 9ecfcdcdd6d6..9ad622ab05dc 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -1256,7 +1256,6 @@ void xen_evtchn_do_upcall(struct pt_regs *regs)
 
 	irq_enter();
 #ifdef CONFIG_X86
-	exit_idle();
 	inc_irq_stat(irq_hv_callback_count);
 #endif
 
-- 
2.11.0.rc1