[tip:smp/hotplug] KVM/x86: Remove superfluous SMP function call

[tip-bot for Anna-Maria Gleixner]

Commit-ID:  162e52a117af5d9c5dfc62b7c2ee90b3e91a7b32
Gitweb:     http://git.kernel.org/tip/162e52a117af5d9c5dfc62b7c2ee90b3e91a7b32
Author:     Anna-Maria Gleixner <anna-maria@xxxxxxxxxxxxx>
AuthorDate: Wed, 13 Jul 2016 17:16:32 +0000
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Fri, 15 Jul 2016 10:40:21 +0200

KVM/x86: Remove superfluous SMP function call

Since the following commit:

  1cf4f629d9d2 ("cpu/hotplug: Move online calls to hotplugged cpu")

... the CPU_ONLINE and CPU_DOWN_PREPARE notifiers are always run on the hot
plugged CPU, and as of commit:

  3b9d6da67e11 ("cpu/hotplug: Fix rollback during error-out in __cpu_disable()")

the CPU_DOWN_FAILED notifier also runs on the hot plugged CPU.  This patch
converts the SMP functional calls into direct calls.

smp_function_call_single() executes the function with interrupts
disabled. This calling convention is not preserved because there
is no reason to do so.

Signed-off-by: Anna-Maria Gleixner <anna-maria@xxxxxxxxxxxxx>
Acked-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Radim Krcmar <rkrcmar@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: kvm@xxxxxxxxxxxxxxx
Cc: rt@xxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20160713153335.452527104@xxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 arch/x86/kvm/x86.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 7da5dd2..6f90595 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5662,15 +5662,13 @@ static struct notifier_block kvmclock_cpufreq_notifier_block = {
 static int kvmclock_cpu_notifier(struct notifier_block *nfb,
 					unsigned long action, void *hcpu)
 {
-	unsigned int cpu = (unsigned long)hcpu;
-
 	switch (action) {
 		case CPU_ONLINE:
 		case CPU_DOWN_FAILED:
-			smp_call_function_single(cpu, tsc_khz_changed, NULL, 1);
+			tsc_khz_changed(NULL);
 			break;
 		case CPU_DOWN_PREPARE:
-			smp_call_function_single(cpu, tsc_bad, NULL, 1);
+			tsc_bad(NULL);
 			break;
 	}
 	return NOTIFY_OK;