On Tue, Jan 12, 2021, Ben Gardon wrote:
> Currently the population stage in the dirty_log_perf_test does nothing
> as the per-vCPU iteration counters are not initialized and the loop does
> not wait for each vCPU. Remedy those errors.
>
> Reviewed-by: Jacob Xu <jacobhxu@xxxxxxxxxx>
> Reviewed-by: Makarand Sonare <makarandsonare@xxxxxxxxxx>
>
> Signed-off-by: Ben Gardon <bgardon@xxxxxxxxxx>
> ---
> tools/testing/selftests/kvm/dirty_log_perf_test.c | 11 ++++++++---
> 1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/tools/testing/selftests/kvm/dirty_log_perf_test.c b/tools/testing/selftests/kvm/dirty_log_perf_test.c
> index 3875f22d7283..fb6eb7fa0b45 100644
> --- a/tools/testing/selftests/kvm/dirty_log_perf_test.c
> +++ b/tools/testing/selftests/kvm/dirty_log_perf_test.c
> @@ -139,14 +139,19 @@ static void run_test(enum vm_guest_mode mode, void *arg)
>
> clock_gettime(CLOCK_MONOTONIC, &start);
> for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
> + vcpu_last_completed_iteration[vcpu_id] = -1;
> +
> pthread_create(&vcpu_threads[vcpu_id], NULL, vcpu_worker,
> &perf_test_args.vcpu_args[vcpu_id]);
> }
>
> - /* Allow the vCPU to populate memory */
> + /* Allow the vCPUs to populate memory */
> pr_debug("Starting iteration %d - Populating\n", iteration);
> - while (READ_ONCE(vcpu_last_completed_iteration[vcpu_id]) != iteration)
> - ;
> + for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
> + while (READ_ONCE(vcpu_last_completed_iteration[vcpu_id]) !=
> + iteration)
Same comment as earlier. I vote to let this poke out, or shorten the variables
so that the lines aren't so long.
> + ;
> + }
>
> ts_diff = timespec_elapsed(start);
> pr_info("Populate memory time: %ld.%.9lds\n",
> --
> 2.30.0.284.gd98b1dd5eaa7-goog
>
