On Wed, 16 Oct 2019 at 17:16, Andrew Jones <drjo...@redhat.com> wrote:
>
> On Wed, Oct 16, 2019 at 04:16:57PM +0100, Beata Michalska wrote:
> > On Wed, 16 Oct 2019 at 14:50, Andrew Jones <drjo...@redhat.com> wrote:
> > >
> > > On Wed, Oct 16, 2019 at 02:24:50PM +0100, Beata Michalska wrote:
> > > > On Tue, 15 Oct 2019 at 12:56, Beata Michalska
> > > > <beata.michal...@linaro.org> wrote:
> > > > >
> > > > > On Tue, 15 Oct 2019 at 11:56, Andrew Jones <drjo...@redhat.com> wrote:
> > > > > >
> > > > > > On Tue, Oct 15, 2019 at 10:59:16AM +0100, Beata Michalska wrote:
> > > > > > > On Tue, 1 Oct 2019 at 14:04, Andrew Jones <drjo...@redhat.com>
> > > > > > > wrote:
> > > > > > > > +
> > > > > > > > + obj = object_new(object_class_get_name(oc));
> > > > > > > > +
> > > > > > > > + if (qdict_in) {
> > > > > > > > + Visitor *visitor;
> > > > > > > > + Error *err = NULL;
> > > > > > > > +
> > > > > > > > + visitor = qobject_input_visitor_new(model->props);
> > > > > > > > + visit_start_struct(visitor, NULL, NULL, 0, &err);
> > > > > > > > + if (err) {
> > > > > > > > + object_unref(obj);
> > > > > > >
> > > > > > > Shouldn't we free the 'visitor' here as well ?
> > > > > >
> > > > > > Yes. Good catch. So we also need to fix
> > > > > > target/s390x/cpu_models.c:cpu_model_from_info(), which has the same
> > > > > > construction (the construction from which I derived this)
> > > > > >
> > > > > > >
> > > > > > > > + error_propagate(errp, err);
> > > > > > > > + return NULL;
> > > > > > > > + }
> > > > > > > > +
> > > > > >
> > > > > > What about the rest of the patch? With that fixed for v6 can I
> > > > > > add your r-b?
> > > > > >
> > > > >
> > > > > I still got this feeling that we could optimize that a bit - which I'm
> > > > > currently on, so hopefully I'll be able to add more comments soon if
> > > > > that proves to be the case.
> > > > >
> > > > > BR
> > > > > Beata
> > > >
> > > > I think there are few options that might be considered though the gain
> > > > is not huge .. but it's always smth:
> > > >
> > > > > +CpuModelExpansionInfo
> > > > > *qmp_query_cpu_model_expansion(CpuModelExpansionType type,
> > > > > + CpuModelInfo
> > > > > *model,
> > > > > + Error **errp)
> > > > > +{
> > > > > + CpuModelExpansionInfo *expansion_info;
> > > > > + const QDict *qdict_in = NULL;
> > > > > + QDict *qdict_out;
> > > > > + ObjectClass *oc;
> > > > > + Object *obj;
> > > > > + const char *name;
> > > > > + int i;
> > > > > +
> > > > > + if (type != CPU_MODEL_EXPANSION_TYPE_FULL) {
> > > > > + error_setg(errp, "The requested expansion type is not
> > > > > supported");
> > > > > + return NULL;
> > > > > + }
> > > > > +
> > > > > + if (!kvm_enabled() && !strcmp(model->name, "host")) {
> > > > > + error_setg(errp, "The CPU type '%s' requires KVM",
> > > > > model->name);
> > > > > + return NULL;
> > > > > + }
> > > > > +
> > > > > + oc = cpu_class_by_name(TYPE_ARM_CPU, model->name);
> > > > > + if (!oc) {
> > > > > + error_setg(errp, "The CPU type '%s' is not a recognized ARM
> > > > > CPU type",
> > > > > + model->name);
> > > > > + return NULL;
> > > > > + }
> > > > > +
> > > > > + if (kvm_enabled()) {
> > > > > + const char *cpu_type = current_machine->cpu_type;
> > > > > + int len = strlen(cpu_type) - strlen(ARM_CPU_TYPE_SUFFIX);
> > > > > + bool supported = false;
> > > > > +
> > > > > + if (!strcmp(model->name, "host") || !strcmp(model->name,
> > > > > "max")) {
> > > > > + /* These are kvmarm's recommended cpu types */
> > > > > + supported = true;
> > > > > + } else if (strlen(model->name) == len &&
> > > > > + !strncmp(model->name, cpu_type, len)) {
> > > > > + /* KVM is enabled and we're using this type, so it
> > > > > works. */
> > > > > + supported = true;
> > > > > + }
> > > > > + if (!supported) {
> > > > > + error_setg(errp, "We cannot guarantee the CPU type '%s'
> > > > > works "
> > > > > + "with KVM on this host", model->name);
> > > > > + return NULL;
> > > > > + }
> > > > > + }
> > > > > +
> > > >
> > > > The above section can be slightly reduced and rearranged - preferably
> > > > moved to a separate function
> > > > -> get_cpu_model (...) ?
> > > >
> > > > * You can check the 'host' model first and then validate the
> > > > accelerator ->
> > > > if ( !strcmp(model->name, "host")
> > > > if (!kvm_enabled())
> > > > log_error & leave
> > > > else
> > > > goto cpu_class_by_name /*cpu_class_by_name moved after the
> > > > final model check @see below */
> > > >
> > > > * the kvm_enabled section can be than slightly improved (dropping the
> > > > second compare against 'host')
> > > >
> > > > if (kvm_enabled() && strcmp(model->name, "max") {
> > > > /*Validate the current_machine->cpu_type against the
> > > > model->name and report error case mismatch
> > > > /* otherwise just fall through */
> > > > }
> > > > * cpu_class_by_name moved here ...
> > > > > + if (model->props) {
> > > > MInor: the CPUModelInfo seems to have dedicated field for that
> > > > verification -> has_props
> > > >
> > > > > + qdict_in = qobject_to(QDict, model->props);
> > > > > + if (!qdict_in) {
> > > > > + error_setg(errp, QERR_INVALID_PARAMETER_TYPE, "props",
> > > > > "dict");
> > > > > + return NULL;
> > > > > + }
> > > > > + }
> > > > > +
> > > > > + obj = object_new(object_class_get_name(oc));
> > > > > +
> > > > > + if (qdict_in) {
> > > > > + Visitor *visitor;
> > > > > + Error *err = NULL;
> > > > > +
> > > > > + visitor = qobject_input_visitor_new(model->props);
> > > > > + visit_start_struct(visitor, NULL, NULL, 0, &err);
> > > > > + if (err) {
> > > > > + object_unref(obj);
> > > > > + error_propagate(errp, err);
> > > > > + return NULL;
> > > > > + }
> > > > > +
> > > > > + i = 0;
> > > > > + while ((name = cpu_model_advertised_features[i++]) != NULL) {
> > > > > + if (qdict_get(qdict_in, name)) {
> > > > > + object_property_set(obj, visitor, name, &err);
> > > > > + if (err) {
> > > > > + break;
> > > > > + }
> > > > > + }
> > > > > + }
> > > > > +
> > > > > + if (!err) {
> > > > > + visit_check_struct(visitor, &err);
> > > > > + }
> > > > > + visit_end_struct(visitor, NULL);
> > > > > + visit_free(visitor);
> > > > > + if (err) {
> > > > > + object_unref(obj);
> > > > > + error_propagate(errp, err);
> > > > > + return NULL;
> > > > > + }
> > > > > + }
> > > >
> > > > The both >> if (err) << blocks could be extracted and moved at the end
> > > > of the function
> > > > to mark a 'cleanup section' and both here and few lines before
> > > > (with the visit_start_struct failure) could use goto.
> > > > Easier to maintain and to make sure we make the proper cleanup in any
> > > > case.
> > > >
> > > > > +
> > > > > + expansion_info = g_new0(CpuModelExpansionInfo, 1);
> > > > > + expansion_info->model =
> > > > > g_malloc0(sizeof(*expansion_info->model));
> > > > > + expansion_info->model->name = g_strdup(model->name);
> > > > > +
> > > > > + qdict_out = qdict_new();
> > > > > +
> > > > > + i = 0;
> > > > > + while ((name = cpu_model_advertised_features[i++]) != NULL) {
> > > > > + ObjectProperty *prop = object_property_find(obj, name, NULL);
> > > > > + if (prop) {
> > > > > + Error *err = NULL;
> > > > > + QObject *value;
> > > > > +
> > > > > + assert(prop->get);
> > > > > + value = object_property_get_qobject(obj, name, &err);
> > > > > + assert(!err);
> > > > > +
> > > > > + qdict_put_obj(qdict_out, name, value);
> > > > > + }
> > > > > + }
> > > > > +
> > > >
> > > > This could be merged with the first iteration over the features,
> > > > smth like:
> > > >
> > > > while () {
> > > > if ((value = qdict_get(qdict_in, name))) {
> > > > object_property_set ...
> > > > if (!err)
> > > > qobject_ref(value) /* we have the weak reference */
> > > > else
> > > > break;
> > > > } else {
> > > > value = object_property_get_qobject()
> > > > }
> > > > if (value) qdict_put_object(qdict_out, name, value)
> > > > }
> > > >
> > > > This way you iterate over the table once and you do not query
> > > > for the same property twice by getting the value from the qdict_in.
> > > > If the value is not acceptable we will fail either way so should be all
> > > > good.
> > > >
> > > >
> > > > > + if (!qdict_size(qdict_out)) {
> > > > > + qobject_unref(qdict_out);
> > > > > + } else {
> > > > > + expansion_info->model->props = QOBJECT(qdict_out);
> > > > > + expansion_info->model->has_props = true;
> > > > > + }
> > > > > +
> > > > > + object_unref(obj);
> > > > > +
> > > > > + return expansion_info;
> > > >
> > > > Mentioned earlier cleanup section:
> > > > cleanup:
> > > > object_unref(obj);
> > > > qobject_unref(qdict_out) ; /* if single loop is used */
> > > > error_propagate(errp,err);
> > > > return NULL;
> > > >
> > > > > +}
> > > > > --
> > > > > 2.20.1
> > > > >
> > > >
> > > > Hope I haven't missed anything.
> > > > What do you think ?
> > > >
> > >
> > > I think you need to post an entire function that incorporates all the
> > > proposed changes, or at least a diff that I can apply in order to get
> > > the entirely changed function. I also think that it's fine the way
> > > it is, so it would take a justification stronger than a potential
> > > micro optimization to get me to change it.
> > >
> >
> > The numbers I can pull out of it are not thrilling and this is not
> > on a fast path so I will not be pushing for changes.
> > Though extracting the clean-up might be worth considering -
> > for improved maintenance.
> >
> > For a reference though:
>
> It doesn't apply for me - even after fixing up the damager your mailer did
> to it. I'd be surprised if it worked though. Merging the two loops over
> features makes the output generation depend on the caller providing input.
> Did you try the arm-cpu-features test with these changes?
>
Apologies for the late reply.
Indeed, the patch got bit messed-up. Apologies for that as well.
I have been testing manually but I did try the test you have provided
and yes it fails - there is a slight problem with the case when qdict_in
is empty,but this can be easily solved still keeping the single loop.
Otherwise I have seen you have posted a new patchest so I guess we are
dropping the idea of refactoring ?
One more question: in case of querying a property which is not supported
by given cpu model - we are returning properties that are actually valid
(the test case for cortex-a15 and aarch64 prop).
Shouldn't we return an error there? I honestly must admit I do not know
what is the expected behaviour for the qmp query in such cases.
Best Regards
Beata
> drew
>
> >
> > _______________________________________________________
> >
> > ---
> > target/arm/monitor.c | 100
> > +++++++++++++++++++++++++--------------------------
> > 1 file changed, 50 insertions(+), 50 deletions(-)
> >
> > diff --git a/target/arm/monitor.c b/target/arm/monitor.c
> > index edca8aa..0d6bd42 100644
> > --- a/target/arm/monitor.c
> > +++ b/target/arm/monitor.c
> > @@ -112,17 +112,40 @@ CpuModelExpansionInfo
> > *qmp_query_cpu_model_expansion(CpuModelExpansionType type,
> > Object *obj;
> > const char *name;
> > int i;
> > + Error *err = NULL;
> >
> > if (type != CPU_MODEL_EXPANSION_TYPE_FULL) {
> > error_setg(errp, "The requested expansion type is not supported");
> > return NULL;
> > }
> >
> > - if (!kvm_enabled() && !strcmp(model->name, "host")) {
> > - error_setg(errp, "The CPU type '%s' requires KVM", model->name);
> > - return NULL;
> > + /* CPU type => 'host' */
> > + if (!strcmp(model->name, "host")) {
> > + if (!kvm_enabled()) {
> > + error_setg(errp, "The CPU type '%s' requires KVM",
> > model->name);
> > + return NULL;
> > + } else {
> > + goto valid;
> > + }
> > + }
> > +
> > +
> > + /* Case when KVM is enabled and the model is a specific cpu model ...
> > */
> > + if (kvm_enabled() && strcmp(model->name, "max")) {
> > + const char *cpu_type = current_machine->cpu_type;
> > + int len = strlen(cpu_type) - strlen("-" TYPE_ARM_CPU);
> > +
> > + if (strlen(model->name) == len
> > + && !strncmp(cpu_type, model->name, len)) {
> > + error_setg(errp, "We cannot guarantee the CPU type '%s'
> > works "
> > + "with KVM on this host", model->name);
> > + return NULL;
> > + }
> > +
> > }
> >
> > +valid:
> > +
> > oc = cpu_class_by_name(TYPE_ARM_CPU, model->name);
> > if (!oc) {
> > error_setg(errp, "The CPU type '%s' is not a recognized ARM CPU
> > type",
> > @@ -130,25 +153,6 @@ CpuModelExpansionInfo
> > *qmp_query_cpu_model_expansion(CpuModelExpansionType type,
> > return NULL;
> > }
> >
> > - if (kvm_enabled()) {
> > - const char *cpu_type = current_machine->cpu_type;
> > - int len = strlen(cpu_type) - strlen(ARM_CPU_TYPE_SUFFIX);
> > - bool supported = false;
> > -
> > - if (!strcmp(model->name, "host") || !strcmp(model->name, "max")) {
> > - /* These are kvmarm's recommended cpu types */
> > - supported = true;
> > - } else if (strlen(model->name) == len &&
> > - !strncmp(model->name, cpu_type, len)) {
> > - /* KVM is enabled and we're using this type, so it works. */
> > - supported = true;
> > - }
> > - if (!supported) {
> > - error_setg(errp, "We cannot guarantee the CPU type '%s' works "
> > - "with KVM on this host", model->name);
> > - return NULL;
> > - }
> > - }
> >
> > if (model->props) {
> > qdict_in = qobject_to(QDict, model->props);
> > @@ -159,62 +163,52 @@ CpuModelExpansionInfo
> > *qmp_query_cpu_model_expansion(CpuModelExpansionType type,
> > }
> >
> > obj = object_new(object_class_get_name(oc));
> > + qdict_out = qdict_new();
> >
> > if (qdict_in) {
> > Visitor *visitor;
> > - Error *err = NULL;
> > + QObject *value;
> >
> > visitor = qobject_input_visitor_new(model->props);
> > visit_start_struct(visitor, NULL, NULL, 0, &err);
> > if (err) {
> > - object_unref(obj);
> > - error_propagate(errp, err);
> > - return NULL;
> > + visit_free(visitor);
> > + goto cleanup;
> > }
> > -
> > i = 0;
> > while ((name = cpu_model_advertised_features[i++]) != NULL) {
> > - if (qdict_get(qdict_in, name)) {
> > + value = qdict_get(qdict_in, name);
> > + if (value) {
> > object_property_set(obj, visitor, name, &err);
> > - if (err) {
> > + if (!err) {
> > + qobject_ref(value);
> > + } else {
> > break;
> > }
> > +
> > + } else {
> > + value = object_property_get_qobject(obj, name, &err);
> > }
> > - }
> >
> > + if (value) {
> > + qdict_put_obj(qdict_out, name, value);
> > + }
> > + }
> > if (!err) {
> > visit_check_struct(visitor, &err);
> > }
> > visit_end_struct(visitor, NULL);
> > visit_free(visitor);
> > if (err) {
> > - object_unref(obj);
> > - error_propagate(errp, err);
> > - return NULL;
> > + goto cleanup;
> > }
> > +
> > }
> >
> > expansion_info = g_new0(CpuModelExpansionInfo, 1);
> > expansion_info->model = g_malloc0(sizeof(*expansion_info->model));
> > expansion_info->model->name = g_strdup(model->name);
> >
> > - qdict_out = qdict_new();
> > -
> > - i = 0;
> > - while ((name = cpu_model_advertised_features[i++]) != NULL) {
> > - ObjectProperty *prop = object_property_find(obj, name, NULL);
> > - if (prop) {
> > - Error *err = NULL;
> > - QObject *value;
> > -
> > - assert(prop->get);
> > - value = object_property_get_qobject(obj, name, &err);
> > - assert(!err);
> > -
> > - qdict_put_obj(qdict_out, name, value);
> > - }
> > - }
> > -
> > if (!qdict_size(qdict_out)) {
> > qobject_unref(qdict_out);
> > } else {
> > @@ -225,4 +219,10 @@ CpuModelExpansionInfo
> > *qmp_query_cpu_model_expansion(CpuModelExpansionType type,
> > object_unref(obj);
> >
> > return expansion_info;
> > +
> > +cleanup:
> > + object_unref(obj);
> > + qobject_unref(qdict_out);
> > + error_propagate(errp, err);
> > + return NULL;
> > }
> > --
> > 2.7.4
> >
> > BR
> > Beata
> >
> > > Thanks,
> > > drew
> >
