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Commit abe9efa7 authored by Paolo Bonzini's avatar Paolo Bonzini
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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: default avatarAndy Lutomirski <luto@kernel.org>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 3aed64f6

arch/x86/entry/vdso/vclock_gettime.c

+3 −13
Original line number Diff line number Diff line
@@ -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;