perf tools: Let a user specify a PMU event without any config terms
authorAdrian Hunter <adrian.hunter@intel.com>
Fri, 15 Aug 2014 19:08:40 +0000 (22:08 +0300)
committerArnaldo Carvalho de Melo <acme@redhat.com>
Wed, 17 Sep 2014 20:08:08 +0000 (17:08 -0300)
commitad96227349901838e1a7f96f1dc22d96a97520c0
tree57fc191394188bd76929821d6fe2accb28b3cad5
parent6997af72e6c1e9d8c1cc511dc9485e9ee69a5e20
perf tools: Let a user specify a PMU event without any config terms

This enables a PMU event to be specified in the form:

pmu//

which is effectively the same as:

pmu/config=0/

This patch is a precursor to defining default config for a PMU.

Further explanation extracted from lkml thread:

Imagine that the 'tsc' term did not exist.

Intel PT trace data would not contain TSC packets, and the decoder would
not know how to decode them.

Then imagine that a new version of the hardware adds 'tsc'.

It is such a useful feature that we want it by default, but older
versions of the tools don't know how to decode it, so the kernel cannot
turn it on by default.

It is similar to why the kernel does not select perf_event_attr.mmap2 by
default.

The kernel doesn't know whether the tool supports it.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1408129739-17368-6-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
tools/perf/util/parse-events.c
tools/perf/util/parse-events.y