@@ -135,6 +135,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
struct timespec ts_diff;
struct kvm_vm *vm;
int i;
+ double vcpu_paging_rate;
vm = memstress_create_vm(mode, nr_vcpus, guest_percpu_mem_size, 1,
p->src_type, p->partition_vcpu_memory_access);
@@ -191,11 +192,17 @@ static void run_test(enum vm_guest_mode mode, void *arg)
uffd_stop_demand_paging(uffd_descs[i]);
}
- pr_info("Total guest execution time: %ld.%.9lds\n",
+ pr_info("Total guest execution time:\t%ld.%.9lds\n",
ts_diff.tv_sec, ts_diff.tv_nsec);
- pr_info("Overall demand paging rate: %f pgs/sec\n",
- memstress_args.vcpu_args[0].pages * nr_vcpus /
- ((double)ts_diff.tv_sec + (double)ts_diff.tv_nsec / NSEC_PER_SEC));
+
+ vcpu_paging_rate =
+ memstress_args.vcpu_args[0].pages
+ / ((double)ts_diff.tv_sec
+ + (double)ts_diff.tv_nsec / NSEC_PER_SEC);
+ pr_info("Per-vcpu demand paging rate:\t%f pgs/sec/vcpu\n",
+ vcpu_paging_rate);
+ pr_info("Overall demand paging rate:\t%f pgs/sec\n",
+ vcpu_paging_rate * nr_vcpus);
memstress_destroy_vm(vm);
Using the overall demand paging rate to measure performance can be slightly misleading when vCPU accesses are not overlapped. Adding more vCPUs will (usually) increase the overall demand paging rate even if performance remains constant or even degrades on a per-vcpu basis. As such, it makes sense to report both the total and per-vcpu paging rates. Signed-off-by: Anish Moorthy <amoorthy@google.com> --- tools/testing/selftests/kvm/demand_paging_test.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-)