Piotr Zarycki <[email protected]> writes: > Replace the open-coded NOP loop with udelay() which was added to KVM > selftests in commit 6b878cbb87bf ("KVM: selftests: Add guest udelay() > utility for x86"). The NOP loop is CPU speed dependent while udelay() > provides a deterministic delay regardless of host CPU frequency. > > Signed-off-by: Piotr Zarycki <[email protected]>
Reviewed-by: Vitaly Kuznetsov <[email protected]> Thanks! > --- > .../testing/selftests/kvm/x86/hyperv_tlb_flush.c | 15 ++------------- > 1 file changed, 2 insertions(+), 13 deletions(-) > > diff --git a/tools/testing/selftests/kvm/x86/hyperv_tlb_flush.c > b/tools/testing/selftests/kvm/x86/hyperv_tlb_flush.c > index c542cc4762b1..4b7f089542c1 100644 > --- a/tools/testing/selftests/kvm/x86/hyperv_tlb_flush.c > +++ b/tools/testing/selftests/kvm/x86/hyperv_tlb_flush.c > @@ -141,17 +141,6 @@ static void swap_two_test_pages(vm_paddr_t pte_gva1, > vm_paddr_t pte_gva2) > *(uint64_t *)pte_gva2 = tmp; > } > > -/* > - * TODO: replace the silly NOP loop with a proper udelay() implementation. > - */ > -static inline void do_delay(void) > -{ > - int i; > - > - for (i = 0; i < 1000000; i++) > - asm volatile("nop"); > -} > - > /* > * Prepare to test: 'disable' workers by setting the expectation to '0', > * clear hypercall input page and then swap two test pages. > @@ -169,7 +158,7 @@ static inline void prepare_to_test(struct test_data *data) > wmb(); > > /* Make sure workers have enough time to notice */ > - do_delay(); > + udelay(100); > > /* Swap test page mappings */ > swap_two_test_pages(data->test_pages_pte[0], data->test_pages_pte[1]); > @@ -189,7 +178,7 @@ static inline void post_test(struct test_data *data, u64 > exp1, u64 exp2) > set_expected_val((void *)data->test_pages, exp2, WORKER_VCPU_ID_2); > > /* Make sure workers have enough time to test */ > - do_delay(); > + udelay(100); > } > > #define TESTVAL1 0x0101010101010101 -- Vitaly
