[patch V2 31/67] KVM/x86: Remove superfluous SMP function call

From: Anna-Maria Gleixner
Date: Wed Jul 13 2016 - 13:30:04 EST


From: Anna-Maria Gleixner <anna-maria@xxxxxxxxxxxxx>

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>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Radim Krcmar <rkrcmar@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: kvm@xxxxxxxxxxxxxxx
---
arch/x86/kvm/x86.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5662,15 +5662,13 @@ static struct notifier_block kvmclock_cp
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;