[tip:perf/core] perf pmu: Improve error messages for missing PMUs

From: tip-bot for Andi Kleen
Date: Fri Sep 22 2017 - 12:45:32 EST


Commit-ID: 333b566559019b146905c623bde7f455c1d5add3
Gitweb: http://git.kernel.org/tip/333b566559019b146905c623bde7f455c1d5add3
Author: Andi Kleen <ak@xxxxxxxxxxxxxxx>
AuthorDate: Wed, 13 Sep 2017 14:50:06 -0700
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Mon, 18 Sep 2017 09:40:20 -0300

perf pmu: Improve error messages for missing PMUs

When a PMU is missing print a better error message mentioning
the missing PMU.

% mkdir empty
% mount --bind empty /sys/devices/msr
% perf stat -M Summary true
event syntax error: '{inst_retired.any,cycles}:W,{cpu_clk_unhalted.thread}:W,{inst_retired.any}:W,{cpu_clk_unhalted.ref_tsc,msr/tsc/}:W,{fp_comp_ops_exe.sse_scalar..'
\___ Cannot find PMU `msr'. Missing kernel support?

It still cannot find the right column for aliases, but it's already a vast improvement.

v2: Check asprintf

Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/20170913215006.32222-1-andi@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/util/metricgroup.c | 2 +-
tools/perf/util/parse-events.c | 18 ++++++++++++------
tools/perf/util/parse-events.h | 3 +++
3 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
index 2d60114..fa37ef7 100644
--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -477,7 +477,7 @@ int metricgroup__parse_groups(const struct option *opt,
memset(&parse_error, 0, sizeof(struct parse_events_error));
ret = parse_events(perf_evlist, extra_events.buf, &parse_error);
if (ret) {
- pr_err("Cannot set up events %s\n", extra_events.buf);
+ parse_events_print_error(&parse_error, extra_events.buf);
goto out;
}
strbuf_release(&extra_events);
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 7558892..9183913 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -1219,11 +1219,17 @@ static int __parse_events_add_pmu(struct parse_events_state *parse_state,
struct perf_pmu_info info;
struct perf_pmu *pmu;
struct perf_evsel *evsel;
+ struct parse_events_error *err = parse_state->error;
LIST_HEAD(config_terms);

pmu = perf_pmu__find(name);
- if (!pmu)
+ if (!pmu) {
+ if (asprintf(&err->str,
+ "Cannot find PMU `%s'. Missing kernel support?",
+ name) < 0)
+ err->str = NULL;
return -EINVAL;
+ }

if (pmu->default_config) {
memcpy(&attr, pmu->default_config,
@@ -1733,8 +1739,8 @@ static int get_term_width(void)
return ws.ws_col > MAX_WIDTH ? MAX_WIDTH : ws.ws_col;
}

-static void parse_events_print_error(struct parse_events_error *err,
- const char *event)
+void parse_events_print_error(struct parse_events_error *err,
+ const char *event)
{
const char *str = "invalid or unsupported event: ";
char _buf[MAX_WIDTH];
@@ -1789,8 +1795,6 @@ static void parse_events_print_error(struct parse_events_error *err,
zfree(&err->str);
zfree(&err->help);
}
-
- fprintf(stderr, "Run 'perf list' for a list of valid events\n");
}

#undef MAX_WIDTH
@@ -1802,8 +1806,10 @@ int parse_events_option(const struct option *opt, const char *str,
struct parse_events_error err = { .idx = 0, };
int ret = parse_events(evlist, str, &err);

- if (ret)
+ if (ret) {
parse_events_print_error(&err, str);
+ fprintf(stderr, "Run 'perf list' for a list of valid events\n");
+ }

return ret;
}
diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index 6351351..3909ca0 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -202,6 +202,9 @@ int is_valid_tracepoint(const char *event_string);
int valid_event_mount(const char *eventfs);
char *parse_events_formats_error_string(char *additional_terms);

+void parse_events_print_error(struct parse_events_error *err,
+ const char *event);
+
#ifdef HAVE_LIBELF_SUPPORT
/*
* If the probe point starts with '%',