[PATCH] perf record/top: handle ENODEV on default cycles event

[David Ahern]

Some systems (e.g., VMs on qemu-0.13 with the default vcpu model) report
an unsupported CPU model:

Performance Events: unsupported p6 CPU model 2 no PMU driver, software events only.

Subsequent invocations of perf fail with:

The sys_perf_event_open() syscall returned with 19 (No such device) for event (cycles).
/bin/dmesg may provide additional information.
No CONFIG_PERF_EVENTS=y kernel support configured?

Add ENODEV to the list of errno's to fallback to cpu-clock.

Signed-off-by: David Ahern <dsahern@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
---
 tools/perf/util/evsel.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index a635461..8bed0c1 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1482,7 +1482,7 @@ out:
 bool perf_evsel__fallback(struct perf_evsel *evsel, int err,
 			  char *msg, size_t msgsize)
 {
-	if ((err == ENOENT || err == ENXIO) &&
+	if ((err == ENOENT || err == ENXIO || err == ENODEV) &&
 	    evsel->attr.type   == PERF_TYPE_HARDWARE &&
 	    evsel->attr.config == PERF_COUNT_HW_CPU_CYCLES) {
 		/*
-- 
1.7.10.1

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