On Thu, Jan 23, 2020 at 10:04:34AM -0800, Ben Gardon wrote: > In order to quantify demand paging performance, time guest execution > during demand paging. > > Signed-off-by: Ben Gardon <bgardon@xxxxxxxxxx> > --- > .../selftests/kvm/demand_paging_test.c | 68 +++++++++++++++++++ > 1 file changed, 68 insertions(+) > > diff --git a/tools/testing/selftests/kvm/demand_paging_test.c b/tools/testing/selftests/kvm/demand_paging_test.c > index 2002032df32cc..0dc5d04718678 100644 > --- a/tools/testing/selftests/kvm/demand_paging_test.c > +++ b/tools/testing/selftests/kvm/demand_paging_test.c > @@ -32,6 +32,12 @@ > > #define DEFAULT_GUEST_TEST_MEM_SIZE (1 << 30) /* 1G */ > > +#ifdef PRINT_PER_PAGE_UPDATES > +#define PER_PAGE_DEBUG(...) DEBUG(__VA_ARGS__) > +#else > +#define PER_PAGE_DEBUG(...) > +#endif > + > #ifdef PRINT_PER_VCPU_UPDATES > #define PER_VCPU_DEBUG(...) DEBUG(__VA_ARGS__) > #else > @@ -64,6 +70,26 @@ static uint64_t guest_test_phys_mem; > */ > static uint64_t guest_test_virt_mem = DEFAULT_GUEST_TEST_MEM; > > +int64_t to_ns(struct timespec ts) > +{ > + return (int64_t)ts.tv_nsec + 1000000000LL * (int64_t)ts.tv_sec; > +} > + > +struct timespec diff(struct timespec start, struct timespec end) > +{ > + struct timespec temp; > + > + if ((end.tv_nsec-start.tv_nsec) < 0) { spaces around the '-' would be nice > + temp.tv_sec = end.tv_sec - start.tv_sec - 1; > + temp.tv_nsec = 1000000000 + end.tv_nsec - start.tv_nsec; > + } else { > + temp.tv_sec = end.tv_sec - start.tv_sec; > + temp.tv_nsec = end.tv_nsec - start.tv_nsec; > + } > + > + return temp; > +} Could probably add these new time utilities to the new test_util.c Thanks, drew