[libvirt] [PATCH] test_driver: implement virDomainGetCPUStats

[Erik Skultety]

On Thu, Jul 18, 2019 at 12:02:43PM +0200, Ilias Stamatis wrote:
> Signed-off-by: Ilias Stamatis <stamatis.iliass at gmail.com>
> ---
>  src/test/test_driver.c | 131 +++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 131 insertions(+)
>
> diff --git a/src/test/test_driver.c b/src/test/test_driver.c
> index fcb80c9e47..2907c043cb 100644
> --- a/src/test/test_driver.c
> +++ b/src/test/test_driver.c
> @@ -3258,6 +3258,136 @@ static int testDomainSetMetadata(virDomainPtr dom,
>      return ret;
>  }
>
> +
> +static int
> +testDomainGetDomainTotalCpuStats(virTypedParameterPtr params,
> +                                int nparams)
> +{
> +    if (nparams == 0) /* return supported number of params */
> +        return 3;
> +
> +    if (virTypedParameterAssign(&params[0], VIR_DOMAIN_CPU_STATS_CPUTIME,
> +                                VIR_TYPED_PARAM_ULLONG, 77102913900) < 0)
> +        return -1;
> +
> +    if (nparams > 1 &&
> +        virTypedParameterAssign(&params[1],
> +                                VIR_DOMAIN_CPU_STATS_USERTIME,
> +                                VIR_TYPED_PARAM_ULLONG, 45650000000) < 0)
> +        return -1;
> +
> +    if (nparams > 2 &&
> +        virTypedParameterAssign(&params[2],
> +                                VIR_DOMAIN_CPU_STATS_SYSTEMTIME,
> +                                VIR_TYPED_PARAM_ULLONG, 11390000000) < 0)
> +        return -1;
> +
> +    if (nparams > 3)
> +        nparams = 3;
> +
> +    return nparams;
> +}
> +
> +
> +static int
> +testDomainGetPercpuStats(virTypedParameterPtr params,
> +                         unsigned int nparams,
> +                         int start_cpu,
> +                         unsigned int ncpus,
> +                         int total_cpus)
> +{
> +    size_t i;
> +    int need_cpus;
> +    int param_idx;
> +    int ret = -1;
> +
> +    /* return the number of supported params */
> +    if (nparams == 0 && ncpus != 0)
> +        return 2;
> +
> +    /* return total number of cpus */
> +    if (ncpus == 0) {
> +        ret = total_cpus;
> +        goto cleanup;
> +    }
> +
> +    if (start_cpu >= total_cpus) {
> +        virReportError(VIR_ERR_INVALID_ARG,
> +                       _("start_cpu %d larger than maximum of %d"),
> +                       start_cpu, total_cpus - 1);
> +        goto cleanup;
> +    }
> +
> +    /* return percpu cputime in index 0 */
> +    param_idx = 0;
> +
> +    /* number of cpus to compute */
> +    need_cpus = MIN(total_cpus, start_cpu + ncpus);
> +
> +    for (i = 0; i < need_cpus; i++) {
> +        if (i < start_cpu)
> +            continue;
> +        int idx = (i - start_cpu) * nparams + param_idx;
> +        if (virTypedParameterAssign(&params[idx],
> +                                    VIR_DOMAIN_CPU_STATS_CPUTIME,
> +                                    VIR_TYPED_PARAM_ULLONG,
> +                                    202542145062 + 10 * i) < 0)

What's the reasoning behind the formula? I'm curious, wouldn't have
202542145062 + i been enough? Anyhow, the CPUTIME should be a portion of the
total cputime of all CPUs, your per-CPU time is much bigger by the total,
that doesn't sound right. I don't care about the exact numbers, but I'd like to
see them to make sense.

Erik