From: Avi Kivity <a...@redhat.com> Scale up iterations until we measure at least 1G cycles.
Signed-off-by: Avi Kivity <a...@redhat.com> diff --git a/kvm/user/test/x86/vmexit.c b/kvm/user/test/x86/vmexit.c index 5088dc9..e7cb5ef 100644 --- a/kvm/user/test/x86/vmexit.c +++ b/kvm/user/test/x86/vmexit.c @@ -17,7 +17,7 @@ static inline unsigned long long rdtsc() return r; } -#define N (1 << 22) +#define GOAL (1ull << 30) #ifdef __x86_64__ # define R "r" @@ -93,6 +93,7 @@ static void do_test(struct test *test) { int i; unsigned long long t1, t2; + unsigned iterations = 32; void (*func)(void) = test->func; if (test->valid && !test->valid()) { @@ -100,11 +101,14 @@ static void do_test(struct test *test) return; } - t1 = rdtsc(); - for (i = 0; i < N; ++i) - func(); - t2 = rdtsc(); - printf("%s %d\n", test->name, (int)((t2 - t1) / N)); + do { + iterations *= 2; + t1 = rdtsc(); + for (i = 0; i < iterations; ++i) + func(); + t2 = rdtsc(); + } while ((t2 - t1) < GOAL); + printf("%s %d\n", test->name, (int)((t2 - t1) / iterations)); } #define ARRAY_SIZE(_x) (sizeof(_x) / sizeof((_x)[0])) -- To unsubscribe from this list: send the line "unsubscribe kvm-commits" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html