On Wed, Jul 15, 2020 at 2:13 PM Jiri Olsa <[email protected]> wrote:
>
> On Tue, Jul 14, 2020 at 05:07:04PM -0700, Ian Rogers wrote:
> > On Sun, Jul 12, 2020 at 6:27 AM Jiri Olsa <[email protected]> wrote:
> > >
> > > Collecting referenced metrics in struct metric_ref_node object,
> > > so we can process them later on.
> > >
> > > The change will parse nested metric names out of expression and
> > > 'resolve' them.
> > >
> > > All referenced metrics are dissolved into one context, meaning all
> > > nested metrics events and added to the parent context.
> > >
> > > Signed-off-by: Jiri Olsa <[email protected]>
> > > ---
> > > tools/perf/util/metricgroup.c | 147 ++++++++++++++++++++++++++++++----
> > > 1 file changed, 132 insertions(+), 15 deletions(-)
> > >
> > > diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
> > > index f0b0a053bfd2..9923eef1e2d4 100644
> > > --- a/tools/perf/util/metricgroup.c
> > > +++ b/tools/perf/util/metricgroup.c
> > > @@ -102,12 +102,20 @@ void metricgroup__rblist_exit(struct rblist
> > > *metric_events)
> > > rblist__exit(metric_events);
> > > }
> > >
> > > +struct metric_ref_node {
> > > + const char *metric_name;
> > > + const char *metric_expr;
> > > + struct list_head list;
> > > +};
> >
> > Perhaps a comment like this above:
> > /* A node in the list of referenced metrics. metric_expr is held as a
> > convenience to avoid a search through the metric list. */
>
> sounds good
>
> >
> > > +
> > > struct egroup {
> > > struct list_head nd;
> > > struct expr_parse_ctx pctx;
> > > const char *metric_name;
> > > const char *metric_expr;
> > > const char *metric_unit;
> > > + struct list_head refs;
> > > + int refs_cnt;
> >
> > A comment would be nice here as refs is a pretty overloaded term. For
> > example, is refs_cnt a reference count for memory management or the
> > length of the refs list? I'm unpopular and would use a long variable
> > name here of something like referenced_metrics for the list.
>
> how about metric_refs ? ;-)
Sounds great, thanks!
Ian
> >
> > > int runtime;
> > > bool has_constraint;
> > > };
> > > @@ -574,27 +582,66 @@ int __weak arch_get_runtimeparam(void)
> > > static int __add_metric(struct list_head *group_list,
> > > struct pmu_event *pe,
> > > bool metric_no_group,
> > > - int runtime)
> > > + int runtime,
> > > + struct egroup **egp)
> >
> > Rather than egp perhaps parent_eg or parent_metric?
>
> I'm changing that later on, but perhaps not to parent_metric,
> which sounds good, I'll check
>
> >
> > > {
> > > + struct metric_ref_node *ref;
> > > struct egroup *eg;
> > >
> > > - eg = malloc(sizeof(*eg));
> > > - if (!eg)
> > > - return -ENOMEM;
> > > + if (*egp == NULL) {
> > > + /*
> > > + * We got in here for the master group,
> > > + * allocate it and put it on the list.
> > > + */
> > > + eg = malloc(sizeof(*eg));
> > > + if (!eg)
> > > + return -ENOMEM;
> > > +
> > > + expr__ctx_init(&eg->pctx);
> > > + eg->metric_name = pe->metric_name;
> > > + eg->metric_expr = pe->metric_expr;
> > > + eg->metric_unit = pe->unit;
> > > + eg->runtime = runtime;
> > > + eg->has_constraint = metric_no_group ||
> > > metricgroup__has_constraint(pe);
> > > + INIT_LIST_HEAD(&eg->refs);
> > > + eg->refs_cnt = 0;
> > > + *egp = eg;
> > > + } else {
> > > + /*
> > > + * We got here for the referenced metric, via the
> > > + * recursive metricgroup__add_metric call, add
> > > + * it to the master group.
> >
> > Probably want to avoid the term master here and below:
> > https://www.kernel.org/doc/html/latest/process/coding-style.html?highlight=language%20master#naming
> > Perhaps parent or referencing metric?
>
> right.. will change
>
> >
> > > + */
> > > + eg = *egp;
> > > +
> > > + ref = malloc(sizeof(*ref));
> > > + if (!ref)
> > > + return -ENOMEM;
> > >
> > > - expr__ctx_init(&eg->pctx);
> > > - eg->metric_name = pe->metric_name;
> > > - eg->metric_expr = pe->metric_expr;
> > > - eg->metric_unit = pe->unit;
> > > - eg->runtime = runtime;
> > > - eg->has_constraint = metric_no_group ||
> > > metricgroup__has_constraint(pe);
> > > + ref->metric_name = pe->metric_name;
> > > + ref->metric_expr = pe->metric_expr;
> > > + list_add(&ref->list, &eg->refs);
> > > + eg->refs_cnt++;
> > > + eg->has_constraint |= metricgroup__has_constraint(pe);
> >
> > Why not metric_no_group here? Perhaps use a function to avoid
> > duplication with the code above.
>
> oops, I think that has_constraint update should not be there at al,
> just for the 'parent' metric, thanks!
>
> >
> > > + }
> > >
> > > + /*
> > > + * For both the master and referenced metrics, we parse
> > > + * all the metric's IDs and add it to the parent context.
> > > + */
> > > if (expr__find_other(pe->metric_expr, NULL, &eg->pctx, runtime) <
> > > 0) {
> > > expr__ctx_clear(&eg->pctx);
> > > free(eg);
> > > return -EINVAL;
> > > }
> > >
> > > + /*
> > > + * We add new group only in the 'master' call,
> > > + * so bail out for referenced metric case.
> > > + */
> > > + if (eg->refs_cnt)
> > > + return 0;
> > > +
> > > if (list_empty(group_list))
> > > list_add(&eg->nd, group_list);
> > > else {
> > > @@ -636,14 +683,63 @@ static struct pmu_event *find_metric(const char
> > > *metric, struct pmu_events_map *
> > >
> > > static int add_metric(struct list_head *group_list,
> > > struct pmu_event *pe,
> > > - bool metric_no_group)
> > > + bool metric_no_group,
> > > + struct egroup **egp);
> > > +
> > > +static int resolve_metric(struct egroup *eg,
> > > + bool metric_no_group,
> > > + struct list_head *group_list,
> > > + struct pmu_events_map *map)
> > > +{
> > > + struct hashmap_entry *cur;
> > > + size_t bkt;
> > > + bool all;
> > > + int ret;
> > > +
> > > + /*
> > > + * Iterate all the parsed IDs and if there's metric,
> > > + * add it to the context.
> > > + */
> >
> > Does this mean that the ID doesn't need to begin "metric:" to
> > reference a different metric as per Andi Kleen's request?
>
> correct, that's why I separated find_metric function earlier,
> now I see I did not put this to the changelog :-\ sry
>
> >
> > > + do {
> > > + all = true;
> > > + hashmap__for_each_entry((&eg->pctx.ids), cur, bkt) {
> > > + struct pmu_event *pe;
> > > +
> > > + pe = find_metric(cur->key, map);
> > > + if (!pe)
> > > + continue;
> > > +
> > > + all = false;
> > > + /* The metric key itself needs to go out.. */
> > > + expr__del_id(&eg->pctx, cur->key);
> > > +
> > > + /* ... and it gets resolved to the parent
> > > context. */
> > > + ret = add_metric(group_list, pe, metric_no_group,
> > > &eg);
> > > + if (ret)
> > > + return ret;
> > > +
> > > + /*
> > > + * We added new metric to hashmap, so we need
> > > + * to break the iteration and start over.
> > > + */
> > > + break;
> > > + }
> > > + } while (!all);
> > > +
> > > + return 0;
> > > +}
>
> SNIP
>
