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authorMinfei Huang <mnghuan@gmail.com>2016-05-28 20:27:43 +0800
committerPaolo Bonzini <pbonzini@redhat.com>2016-06-27 15:12:15 +0200
commited911b43adb889c37a37fa57a995f0b460c633b6 (patch)
tree8ddec33ffec607c9255063dfd388c6b69249a378 /arch/x86/kernel/pvclock.c
parentf7550d076d55c1b5f02f95012e3a5a84d264c47d (diff)
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>
Diffstat (limited to 'arch/x86/kernel/pvclock.c')
-rw-r--r--arch/x86/kernel/pvclock.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/x86/kernel/pvclock.c b/arch/x86/kernel/pvclock.c
index 7f82fe0a6807..06c58ce46762 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);