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| author | Paolo Bonzini <pbonzini@redhat.com> | 2016-06-09 20:12:34 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2016-08-04 13:52:21 +0200 |
| commit | abe9efa79be02cf2ba27f643b214b07877bb050b (patch) | |
| tree | c6dc89fa650f50a2409307d0a92ed00d5d8fbb32 /arch | |
| parent | pvclock: introduce seqcount-like API (diff) | |
| download | linux-abe9efa79be02cf2ba27f643b214b07877bb050b.tar.xz linux-abe9efa79be02cf2ba27f643b214b07877bb050b.zip | |
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>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/entry/vdso/vclock_gettime.c | 16 |
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; |