[libvirt] [PATCH v2 2/2] test_driver: implement virDomainGetCPUStats

Ilias Stamatis stamatis.iliass at gmail.com
Mon Jul 29 13:42:34 UTC 2019


On Mon, Jul 29, 2019 at 3:28 PM Erik Skultety <eskultet at redhat.com> wrote:
>
> On Sun, Jul 28, 2019 at 12:02:21PM +0200, Ilias Stamatis wrote:
> > Signed-off-by: Ilias Stamatis <stamatis.iliass at gmail.com>
> > ---
> >  src/test/test_driver.c | 132 +++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 132 insertions(+)
> >
> > diff --git a/src/test/test_driver.c b/src/test/test_driver.c
> > index ab0f8b06d6..56f08fc3d2 100755
> > --- a/src/test/test_driver.c
> > +++ b/src/test/test_driver.c
> > @@ -3629,6 +3629,137 @@ static int testDomainSetMetadata(virDomainPtr dom,
> >      return ret;
> >  }
> >
> > +#define TEST_TOTAL_CPUTIME 48772617035
>
> Let's be explicit with ullong ^here by adding LL

Oops. I had seen Daniel's comment but forgot to apply.

>
> > +
> > +static int
> > +testDomainGetDomainTotalCpuStats(virTypedParameterPtr params,
> > +                                int nparams)
>
> indent is off
>
> > +{
> > +    if (nparams == 0) /* return supported number of params */
> > +        return 3;
> > +
> > +    if (virTypedParameterAssign(&params[0], VIR_DOMAIN_CPU_STATS_CPUTIME,
> > +                                VIR_TYPED_PARAM_ULLONG, TEST_TOTAL_CPUTIME) < 0)
> > +        return -1;
> > +
> > +    if (nparams > 1 &&
> > +        virTypedParameterAssign(&params[1],
> > +                                VIR_DOMAIN_CPU_STATS_USERTIME,
> > +                                VIR_TYPED_PARAM_ULLONG, 5540000000) < 0)
> > +        return -1;
> > +
> > +    if (nparams > 2 &&
> > +        virTypedParameterAssign(&params[2],
> > +                                VIR_DOMAIN_CPU_STATS_SYSTEMTIME,
> > +                                VIR_TYPED_PARAM_ULLONG, 6460000000) < 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;
>
> @ret is unnecessary, see below
>
> > +
> > +    /* 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;
>
>         return total_cpus;
>
> > +    }
> > +
> > +    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 -1;
>
> > +    }
> > +
> > +    /* 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;
>
> How about initializing i = start_cpu straight away instead?
>
> > +        int idx = (i - start_cpu) * nparams + param_idx;
> > +        if (virTypedParameterAssign(&params[idx],
> > +                                    VIR_DOMAIN_CPU_STATS_CPUTIME,
> > +                                    VIR_TYPED_PARAM_ULLONG,
> > +                                    (TEST_TOTAL_CPUTIME / total_cpus) + i) < 0)
>
> I'd strongly prefer if we didn't perform the division in each iteration,

I think the compiler will be smart enough to optimize this? But ok
sure, let's not make assumptions.

> the "+ i" also seems unnecessary.

I just added it in order for different CPUs to return different values.
+1, +2 etc. are trivial quantities so the results still make sense imo


>
> > +            goto cleanup;
>
>         return -1;
>
> > +    }
> > +
> > +    /* return percpu vcputime in index 1 */
> > +    param_idx = 1;
> > +
> > +    if (param_idx < nparams) {
> > +        for (i = start_cpu; i < need_cpus; i++) {
> > +            int idx = (i - start_cpu) * nparams + param_idx;
> > +            if (virTypedParameterAssign(&params[idx],
> > +                                        VIR_DOMAIN_CPU_STATS_VCPUTIME,
> > +                                        VIR_TYPED_PARAM_ULLONG,
> > +                                        (TEST_TOTAL_CPUTIME / total_cpus) - 1234567890 + i) < 0)
>
> Same as above...
>
> > +                goto cleanup;
>
>         return -1;
>
> > +        }
> > +        param_idx++;
> > +    }
> > +
> > +    ret = param_idx;
>
> return param_idx;
>
> > + cleanup:
> > +    return ret;
>
> Drop the cleanup label.

Yeah, totally. That was a leftover from previous code and I didn't
realize it after adjusting.

>
> > +}
> > +
> > +
> > +static int
> > +testDomainGetCPUStats(virDomainPtr dom,
> > +                      virTypedParameterPtr params,
> > +                      unsigned int nparams,
> > +                      int start_cpu,
> > +                      unsigned int ncpus,
> > +                      unsigned int flags)
> > +{
> > +    virDomainObjPtr vm = NULL;
> > +    testDriverPtr privconn = dom->conn->privateData;
> > +    int ret = -1;
> > +
> > +    virCheckFlags(VIR_TYPED_PARAM_STRING_OKAY, -1);
> > +
> > +    if (!(vm = testDomObjFromDomain(dom)))
> > +        return -1;
> > +
> > +    if (virDomainObjCheckActive(vm) < 0)
> > +        goto cleanup;
> > +
> > +    if (start_cpu == -1)
> > +        ret = testDomainGetDomainTotalCpuStats(params, nparams);
> > +    else
> > +        ret = testDomainGetPercpuStats(params, nparams, start_cpu, ncpus,
> > +                                       privconn->nodeInfo.cores);
> > +
> > + cleanup:
> > +    virDomainObjEndAPI(&vm);
> > +    return ret;
> > +}
> > +
> > +
> >  static int
> >  testDomainSendProcessSignal(virDomainPtr dom,
> >                              long long pid_value,
> > @@ -8552,6 +8683,7 @@ static virHypervisorDriver testHypervisorDriver = {
> >      .domainSendKey = testDomainSendKey, /* 5.5.0 */
> >      .domainGetMetadata = testDomainGetMetadata, /* 1.1.3 */
> >      .domainSetMetadata = testDomainSetMetadata, /* 1.1.3 */
> > +    .domainGetCPUStats = testDomainGetCPUStats, /* 5.6.0 */
> >      .domainSendProcessSignal = testDomainSendProcessSignal, /* 5.5.0 */
> >      .connectGetCPUModelNames = testConnectGetCPUModelNames, /* 1.1.3 */
> >      .domainManagedSave = testDomainManagedSave, /* 1.1.4 */
> > --
>
> I'll adjust the code before merging.

Sure, thanks for the review!

Ilias

> Reviewed-by: Erik Skultety <eskultet at redhat.com>




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