[PATCH 2/3] pvclock: Cleanup to remove function pvclock_get_nsec_offset

From: Minfei Huang
Date: Fri May 27 2016 - 02:17:22 EST


Function __pvclock_read_cycles is short enough, so there is no need to
have another function pvclock_get_nsec_offset to calculate tsc delta.
It's better to combine it into function __pvclock_read_cycles.

Remove useless variables in function __pvclock_read_cycles.

Signed-off-by: Minfei Huang <mnghuan@xxxxxxxxx>
---
arch/x86/include/asm/pvclock.h | 23 +++++++----------------
1 file changed, 7 insertions(+), 16 deletions(-)

diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h
index 538ae94..7c1c895 100644
--- a/arch/x86/include/asm/pvclock.h
+++ b/arch/x86/include/asm/pvclock.h
@@ -69,31 +69,22 @@ static inline u64 pvclock_scale_delta(u64 delta, u32 mul_frac, int shift)
}

static __always_inline
-u64 pvclock_get_nsec_offset(const struct pvclock_vcpu_time_info *src)
-{
- u64 delta = rdtsc_ordered() - src->tsc_timestamp;
- return pvclock_scale_delta(delta, src->tsc_to_system_mul,
- src->tsc_shift);
-}
-
-static __always_inline
unsigned __pvclock_read_cycles(const struct pvclock_vcpu_time_info *src,
cycle_t *cycles, u8 *flags)
{
unsigned version;
- cycle_t ret, offset;
- u8 ret_flags;
+ cycle_t offset;
+ u64 delta;

version = src->version;
/* Make the latest version visible */
smp_rmb();

- offset = pvclock_get_nsec_offset(src);
- ret = src->system_time + offset;
- ret_flags = src->flags;
-
- *cycles = ret;
- *flags = ret_flags;
+ delta = rdtsc_ordered() - src->tsc_timestamp;
+ offset = pvclock_scale_delta(delta, src->tsc_to_system_mul,
+ src->tsc_shift);
+ *cycles = src->system_time + offset;
+ *flags = src->flags;
return version;
}

--
2.6.3