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perf evsel: Handle ENODEV on default cycles event 

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@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1374190079-28507-1-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
David Ahern 2013-07-18 17:27:59 -06:00 committed by Arnaldo Carvalho de Melo
parent 2eaa1b407a
commit 2b821cce1c
1 changed files with 1 additions and 1 deletions
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2
tools/perf/util/evsel.c
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@ -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) {
/*