From ab483d8bc8acb83f0103bc38ef8f2c27d98ffd1b Mon Sep 17 00:00:00 2001 From: Kan Liang Date: Mon, 24 Feb 2020 13:59:23 -0800 Subject: [PATCH] perf metricgroup: Support metric constraint Some metric groups have metric constraints. A metric group can be scheduled as a group only when some constraints are applied. For example, Page_Walks_Utilization has a metric constraint, "NO_NMI_WATCHDOG". When NMI watchdog is disabled, the metric group can be scheduled as a group. Otherwise, splitting the metric group into standalone metrics. Add a new function, metricgroup__has_constraint(), to check whether all constraints are applied. If not, splitting the metric group into standalone metrics. Currently, only one constraint, "NO_NMI_WATCHDOG", is checked. Print a warning for the metric group with the constraint, when NMI WATCHDOG is enabled. Signed-off-by: Kan Liang Acked-by: Jiri Olsa Cc: Andi Kleen Cc: Jin Yao Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Ravi Bangoria Link: http://lore.kernel.org/lkml/1582581564-184429-5-git-send-email-kan.liang@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/metricgroup.c | 54 ++++++++++++++++++++++++++++++++++- 1 file changed, 53 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c index 1cd042cb262e..c3a8c701609a 100644 --- a/tools/perf/util/metricgroup.c +++ b/tools/perf/util/metricgroup.c @@ -22,6 +22,8 @@ #include #include #include +#include +#include "util.h" struct metric_event *metricgroup__lookup(struct rblist *metric_events, struct evsel *evsel, @@ -429,6 +431,49 @@ static void metricgroup__add_metric_weak_group(struct strbuf *events, strbuf_addf(events, "}:W"); } +static void metricgroup__add_metric_non_group(struct strbuf *events, + const char **ids, + int idnum) +{ + int i; + + for (i = 0; i < idnum; i++) + strbuf_addf(events, ",%s", ids[i]); +} + +static void metricgroup___watchdog_constraint_hint(const char *name, bool foot) +{ + static bool violate_nmi_constraint; + + if (!foot) { + pr_warning("Splitting metric group %s into standalone metrics.\n", name); + violate_nmi_constraint = true; + return; + } + + if (!violate_nmi_constraint) + return; + + 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"); +} + +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()) { + metricgroup___watchdog_constraint_hint(pe->metric_name, false); + return true; + } + + return false; +} + static int metricgroup__add_metric(const char *metric, struct strbuf *events, struct list_head *group_list) { @@ -460,7 +505,10 @@ 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) { @@ -502,6 +550,10 @@ static int metricgroup__add_metric_list(const char *list, struct strbuf *events, } } free(nlist); + + if (!ret) + metricgroup___watchdog_constraint_hint(NULL, true); + return ret; }