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authorPaolo Bonzini2016-06-09 20:12:34 +0200
committerPaolo Bonzini2016-08-04 13:52:21 +0200
commitabe9efa79be02cf2ba27f643b214b07877bb050b (patch)
treec6dc89fa650f50a2409307d0a92ed00d5d8fbb32
parent3aed64f6d341cdb62bb2d6232589fb13448ce063 (diff)
x86: vdso: use __pvclock_read_cycles
The new simplified __pvclock_read_cycles does the same computation as vread_pvclock, except that (because it takes the pvclock_vcpu_time_info pointer) it has to be moved inside the loop. Since the loop is expected to never roll, this makes no difference. Acked-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r--arch/x86/entry/vdso/vclock_gettime.c16
1 files changed, 3 insertions, 13 deletions
diff --git a/arch/x86/entry/vdso/vclock_gettime.c b/arch/x86/entry/vdso/vclock_gettime.c
index db1e3b4c3693..94d54d0defa7 100644
--- a/arch/x86/entry/vdso/vclock_gettime.c
+++ b/arch/x86/entry/vdso/vclock_gettime.c
@@ -96,9 +96,8 @@ static notrace cycle_t vread_pvclock(int *mode)
{
const struct pvclock_vcpu_time_info *pvti = &get_pvti0()->pvti;
cycle_t ret;
- u64 tsc, pvti_tsc;
- u64 last, delta, pvti_system_time;
- u32 version, pvti_tsc_to_system_mul, pvti_tsc_shift;
+ u64 last;
+ u32 version;
/*
* Note: The kernel and hypervisor must guarantee that cpu ID
@@ -130,18 +129,9 @@ static notrace cycle_t vread_pvclock(int *mode)
return 0;
}
- tsc = rdtsc_ordered();
- pvti_tsc_to_system_mul = pvti->tsc_to_system_mul;
- pvti_tsc_shift = pvti->tsc_shift;
- pvti_system_time = pvti->system_time;
- pvti_tsc = pvti->tsc_timestamp;
+ ret = __pvclock_read_cycles(pvti);
} while (pvclock_read_retry(pvti, version));
- delta = tsc - pvti_tsc;
- ret = pvti_system_time +
- pvclock_scale_delta(delta, pvti_tsc_to_system_mul,
- pvti_tsc_shift);
-
/* refer to vread_tsc() comment for rationale */
last = gtod->cycle_last;