From ed911b43adb889c37a37fa57a995f0b460c633b6 Mon Sep 17 00:00:00 2001
From: Minfei Huang <mnghuan@gmail.com>
Date: Sat, 28 May 2016 20:27:43 +0800
Subject: [PATCH] pvclock: Get rid of __pvclock_read_cycles in function
pvclock_read_flags
There is a generic function __pvclock_read_cycles to be used to get both
flags and cycles. For function pvclock_read_flags, it's useless to get
cycles value. To make this function be more effective, get this variable
flags directly in function.
Signed-off-by: Minfei Huang <mnghuan@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kernel/pvclock.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/pvclock.c b/arch/x86/kernel/pvclock.c
index 7f82fe0a6807c..06c58ce46762e 100644
--- a/arch/x86/kernel/pvclock.c
+++ b/arch/x86/kernel/pvclock.c
@@ -61,11 +61,14 @@ void pvclock_resume(void)
u8 pvclock_read_flags(struct pvclock_vcpu_time_info *src)
{
unsigned version;
- cycle_t ret;
u8 flags;
do {
- version = __pvclock_read_cycles(src, &ret, &flags);
+ version = src->version;
+ /* Make the latest version visible */
+ smp_rmb();
+
+ flags = src->flags;
/* Make sure that the version double-check is last. */
smp_rmb();
} while ((src->version & 1) || version != src->version);
--
2.30.2