[PATCH v1 3/4] perf stat: Fix group lookup for metric group

From: Andi Kleen
Date: Mon Jun 24 2019 - 15:37:24 EST


From: Andi Kleen <ak@xxxxxxxxxxxxxxx>

The metric group code tries to find a group it added earlier
in the evlist. Fix the lookup to handle groups with partially
overlaps correctly. When a sub string match fails and we reset
the match, we have to compare the first element again.

I also renamed the find_evsel function to find_evsel_group
to make its purpose clearer.

With the earlier changes this fixes:

Before:

% perf stat -M UPI,IPC sleep 1
...
1,032,922 uops_retired.retire_slots # 1.1 UPI
1,896,096 inst_retired.any
1,896,096 inst_retired.any
1,177,254 cpu_clk_unhalted.thread

After:

% perf stat -M UPI,IPC sleep 1
...
1,013,193 uops_retired.retire_slots # 1.1 UPI
932,033 inst_retired.any
932,033 inst_retired.any # 0.9 IPC
1,091,245 cpu_clk_unhalted.thread

Fixes: b18f3e365019 ("perf stat: Support JSON metrics ...")
Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
---
tools/perf/util/metricgroup.c | 47 ++++++++++++++++++++++++++---------
1 file changed, 35 insertions(+), 12 deletions(-)

diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
index 699e020737d9..fabdb6dde88e 100644
--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -85,26 +85,49 @@ struct egroup {
const char *metric_expr;
};

-static struct perf_evsel *find_evsel(struct perf_evlist *perf_evlist,
- const char **ids,
- int idnum,
- struct perf_evsel **metric_events)
+static bool record_evsel(int *ind, struct perf_evsel **start,
+ int idnum,
+ struct perf_evsel **metric_events,
+ struct perf_evsel *ev)
+{
+ metric_events[*ind] = ev;
+ if (*ind == 0)
+ *start = ev;
+ if (++*ind == idnum) {
+ metric_events[*ind] = NULL;
+ return true;
+ }
+ return false;
+}
+
+static struct perf_evsel *find_evsel_group(struct perf_evlist *perf_evlist,
+ const char **ids,
+ int idnum,
+ struct perf_evsel **metric_events)
{
struct perf_evsel *ev, *start = NULL;
int ind = 0;

evlist__for_each_entry (perf_evlist, ev) {
+ if (ev->collect_stat)
+ continue;
if (!strcmp(ev->name, ids[ind])) {
- metric_events[ind] = ev;
- if (ind == 0)
- start = ev;
- if (++ind == idnum) {
- metric_events[ind] = NULL;
+ if (record_evsel(&ind, &start, idnum,
+ metric_events, ev))
return start;
- }
} else {
+ /*
+ * We saw some other event that is not
+ * in our list of events. Discard
+ * the whole match and start again.
+ */
ind = 0;
start = NULL;
+ if (!strcmp(ev->name, ids[ind])) {
+ if (record_evsel(&ind, &start, idnum,
+ metric_events, ev))
+ return start;
+ }
}
}
/*
@@ -134,8 +157,8 @@ static int metricgroup__setup_events(struct list_head *groups,
ret = -ENOMEM;
break;
}
- evsel = find_evsel(perf_evlist, eg->ids, eg->idnum,
- metric_events);
+ evsel = find_evsel_group(perf_evlist, eg->ids, eg->idnum,
+ metric_events);
if (!evsel) {
pr_debug("Cannot resolve %s: %s\n",
eg->metric_name, eg->metric_expr);
--
2.20.1