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| author | Piotr Zarycki <piotr.zarycki@gmail.com> | 2026-04-22 16:03:07 +0300 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2026-05-13 19:54:44 +0300 |
| commit | 749fbf2bdcd71f6fdd2524f0f8102e1be38f3254 (patch) | |
| tree | 380cb6e552fcd3435cfa7ea48fcacfcd02ed32f1 | |
| parent | b67c030f4f6589c574d98de4f3c4ea3efee9b2be (diff) | |
| download | linux-749fbf2bdcd71f6fdd2524f0f8102e1be38f3254.tar.xz | |
KVM: selftests: hyperv_tlb_flush: replace NOP loop with udelay()
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 <piotr.zarycki@gmail.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://patch.msgid.link/20260422130307.1171808-1-piotr.zarycki@gmail.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
| -rw-r--r-- | tools/testing/selftests/kvm/x86/hyperv_tlb_flush.c | 15 |
1 files 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 15ee8b7bfc11..b4be9a175379 100644 --- a/tools/testing/selftests/kvm/x86/hyperv_tlb_flush.c +++ b/tools/testing/selftests/kvm/x86/hyperv_tlb_flush.c @@ -142,17 +142,6 @@ static void swap_two_test_pages(gpa_t pte_gva1, gpa_t pte_gva2) } /* - * 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 |