Re: [PATCH 4/5] perf metricgroup: Support metric constraint

From: Jiri Olsa
Date: Thu Feb 20 2020 - 06:35:43 EST


On Wed, Feb 19, 2020 at 11:08:39AM -0800, kan.liang@xxxxxxxxxxxxxxx wrote:

SNIP

> +static bool violate_nmi_constraint;
> +
> +static bool metricgroup__has_constraint(struct pmu_event *pe)
> +{
> + if (!pe->metric_constraint)
> + return false;
> +
> + if (!strcmp(pe->metric_constraint, "NO_NMI_WATCHDOG") &&
> + sysctl__nmi_watchdog_enabled()) {
> + pr_warning("Splitting metric group %s into standalone metrics.\n",
> + pe->metric_name);
> + violate_nmi_constraint = true;

no static flags plz.. can't you just print that rest of the warning in here?

jirka

> + return true;
> + }
> +
> + return false;
> +}
> +
> static int metricgroup__add_metric(const char *metric, struct strbuf *events,
> struct list_head *group_list)
> {
> @@ -460,7 +490,10 @@ static int metricgroup__add_metric(const char *metric, struct strbuf *events,
> if (events->len > 0)
> strbuf_addf(events, ",");
>
> - metricgroup__add_metric_weak_group(events, ids, idnum);
> + if (metricgroup__has_constraint(pe))
> + metricgroup__add_metric_non_group(events, ids, idnum);
> + else
> + metricgroup__add_metric_weak_group(events, ids, idnum);
>
> eg = malloc(sizeof(struct egroup));
> if (!eg) {
> @@ -544,6 +577,13 @@ int metricgroup__parse_groups(const struct option *opt,
> strbuf_release(&extra_events);
> ret = metricgroup__setup_events(&group_list, perf_evlist,
> metric_events);
> +
> + if (violate_nmi_constraint) {
> + pr_warning("Try disabling the NMI watchdog to comply NO_NMI_WATCHDOG metric constraint:\n"
> + " echo 0 > /proc/sys/kernel/nmi_watchdog\n"
> + " perf stat ...\n"
> + " echo 1 > /proc/sys/kernel/nmi_watchdog\n");
> + }
> out:
> metricgroup__free_egroups(&group_list);
> return ret;
> --
> 2.7.4
>