[PATCH v1 2/6] perf pmu: Drop "default_core" from alias names

[Ian Rogers <irogers@google.com>]

"default_core" is used by jevents.py for json events' PMU name when
none is specified. On x86 the "default_core" is typically the PMU
"cpu". When creating an alias see if the event's PMU name is
"default_core" in which case don't record it. This means in places
like "perf list" the PMU's name will be used in its place.

Before:
```
$ perf list --details
...
cache:
  l1d.replacement
       [Counts the number of cache lines replaced in L1 data cache]
        default_core/event=0x51,period=0x186a3,umask=0x1/
...
```

After:
```
$ perf list --details
...
cache:
  l1d.replacement
       [Counts the number of cache lines replaced in L1 data cache. Unit: cpu]
        cpu/event=0x51,period=0x186a3,umask=0x1/
...
```

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/pmu.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index f39cbbc1a7ec..24be587e3537 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -518,7 +518,8 @@ static int perf_pmu__new_alias(struct perf_pmu *pmu, const char *name,
 		unit = pe->unit;
 		perpkg = pe->perpkg;
 		deprecated = pe->deprecated;
-		pmu_name = pe->pmu;
+		if (pe->pmu && strcmp(pe->pmu, "default_core"))
+			pmu_name = pe->pmu;
 	}
 
 	alias = zalloc(sizeof(*alias));
-- 
2.44.0.278.ge034bb2e1d-goog