[PATCH 2/2] perf tool: evsel: say which PMU Hardware event doesn't support sampling/overflow-interrupts

[Kim Phillips]

Help identify to the user the event with the unsupported sampling
error.  Also provide an alternative action.

BEFORE:

$ sudo ./oldperf record -e 
armv8_pmuv3/mem_access/,ccn/cycles/,armv8_pmuv3/l2d_cache/ true
Error:
PMU Hardware doesn't support sampling/overflow-interrupts.

AFTER:

$ sudo ./newperf record -e 
armv8_pmuv3/mem_access/,ccn/cycles/,armv8_pmuv3/l2d_cache/ true
Error:
ccn/cycles/: PMU Hardware doesn't support sampling/overflow-interrupts. Try 
'perf stat'

Signed-off-by: Kim Phillips <kim.phill...@arm.com>
---
 tools/perf/util/evsel.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index f894893c203d..a0f298726324 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2739,8 +2739,9 @@ int perf_evsel__open_strerror(struct perf_evsel *evsel, 
struct target *target,
                break;
        case EOPNOTSUPP:
                if (evsel->attr.sample_period != 0)
-                       return scnprintf(msg, size, "%s",
-       "PMU Hardware doesn't support sampling/overflow-interrupts.");
+                       return scnprintf(msg, size,
+       "%s: PMU Hardware doesn't support sampling/overflow-interrupts. Try 
'perf stat'",
+                                        perf_evsel__name(evsel));
                if (evsel->attr.precise_ip)
                        return scnprintf(msg, size, "%s",
        "\'precise\' request may not be supported. Try removing 'p' modifier.");
-- 
2.14.2